Corrosion & Metallic Coatings Workshop

Volume 12, Issue 2: September 2015 (61)

1. Intergalva 2015: The Global Galvanizing Awards.
2. Report on Intergalva 2015
3. Forms of Corrosion: Corrosion due to incorrect selection of materials
4. Forms of Corrosion: White rust and wet storage stains
5. Bob’s Banter: The role of mathematics education in industry

Volume 12, Issue 1: May 2015 (60)

1. Hot DipGalvanizing: A cost effective protection system.
2. Advertorial:How to achieve savings and a better galvanizing finish with nickel tablets
3. Rail Fasteners:Performance of hot dip galvanized resilient rail fasteners exposed in a severe marine environment
4. Reinforcing in Steel: Shouldn’t more rebar be galvanized?
5. Soil side corrosion
6. High Strength Bolts:The use of high strength bolting assemblies for pre-loading
7. Understanding Distortion
8. Case Study:The performance of Pandrol rail fasteners in a marine environment on the Natal South Coast
9. Bob’s Banter: Doublespeak

Volume 11, Issue 3: November 2014 (59)

1. Projects in the Spotlight: Kirstenbosch Tree Top Walkways.
2. Projects in the Spotlight: Redevelopment of the Tramways Building, Port Elizabeth
3. Projects in the Spotlight: New Military Health Base Depot
4. Projects in the Spotlight: The Last Glass House–new residence in Parktown
5. Projects in the Spotlight: The Druenberg Solar Power Project
6. Projects in the Spotlight: Blast protection covers at Syferfontein
7. Projects in the Spotlight: Cellular towers at Cell C Headquarters in Midrand
8. Projects in the Spotlight: Conveyor river bridges.
9. Projects in the Spotlight: Uzizi Pedestrian Bridge in the Tugela Ferry District
10. Projects in the Spotlight: Beth Diane Armstrong; artist
11. Projects in the Spotlight: New bulk liquid berth and floating breakwater
12. Projects in the Spotlight: Transformer radiators for Eskom or local authority sub stations
13. Projects in the Spotlight: Landing Platforms, Saldanha Bay
14. Bob’s Banter: Achieving our desired future means managing the unexpected
15. Conference: The use of hot dip galvanizing in mining in Southern Africa (part 3)
16. Opinion:General galvanizing–how does SA compare globally? (part 2–technology)
17. On the Couch…. With Mark Thomas and Henry Fagan

Volume 11, Issue 2: November 2014 (58)

Volume 11, Issue 1: November 2014 (57)

1. Conference: The use of hot dip galvanizing in mining in Southern Africa – part one.
2. Case Study: Eskom Coastal Sub-Stations.
3. Case Study: Bellville Transport Interchange upgrade built in 2002 stands the test of time.
4. Duplex: Duplex coating good after 14 years of mild to moderate marine exposure.
5. Poles & Masts: Leading steel pole manufacturer takes delivery of high-end CNC machines.
6. Opinion: General galvanizing – how does SA compare globally? Part 1 – The Market.
7. General: Effectively avoiding weld spatter dramatically increases the quality of the hot dipgalvanized coating.
8. Technical: The difference between Hydrogen and Strain Age Embrittlement.
9. Galvpatch successfully exposed to fridge conditions at minus 25ºC for 8 months
10. Education and Training: Three day Galvanizers Inspectors Course

Volume 10, Issue 4: November 2013 (56)

1. The World of Hot Dip Galvanizing around Us: American Galvanizers Association – Metrolina Greenhouses, South Campus Central Chiller Plant, Franklin Park Conservatory, Blast Deflectors, Brea Power Plant, Electric Vehicle Rail Tramway, Gibbs Street Pedestrian Bridge, Platt Street Bridge Restoration, Solaris Tower, The Christina and John Markey Memorial Pedestrian Bridge, Winged Glory, WinStar Casino Globe.
2. The World of Hot Dip Galvanizing around Us: Galvanizers Association of Australia – Making the moment last long, High stakes skin for Star extension, Galvanized finish guards new rail work, From pit to prestige sport centre, Upholding very green park build.
3. Duplex Coatings: Effective corrosion protection of structural steel
4. General: Thermal Spray Association of Southern Africa (TSASA).
5. Education: Three day Galvanizers Inspectors Course
6. Education: Beware – Salt spray testing! Misleading accelerated corrosion tests
7. Education: Accelerated test methods applied to zinc coatings in terms of SANS 14713 – 1:2011
8. Education: Guide to hot dip galvanizing for sustainable design
9. General: Letter to the Editor
10. On the Couch …. Robert JW Brusse
11. Members News: The Advanced Roof and Building Technology Foundation
12. Members News: What passivation is in practice and what it is not
13. Members News: Fresh dynamics at Cape Galvanising Consolidated
14. Members News: Transvaal Galvanisers
15. Members News: ArcelorMittal involvement in Solar and LSF (Light Steel Frame) Projects
16. Bob’s Banter: Achieving our desired future means managing the unexpected

Volume 13, Issue 1: April 2016 (62)

1. Metallurgical investigation into the origin of cracks at welded connections on a hot dip galvanized
   fabricated structural steel perimeter walkway platform.
2. Galvanizing of steel – all around us.
3. Design considerations: venting and drainage
4. Materials of Construction
5. Purlins manufactured from hot dip coil
6. Bob’s Banter: What a disappointment – there are no black holes!
7. Case Study – Rural Pedestrian Bridges
8. Personality Profile – Bob Wilmot
9. 2016 Annual Golf Day

1. APPEARANCE OF SODIUM DICHROMATE

What is this?

A small amount of Sodium Dichromate is generally added to the quench water bath for passivation.

Cause

Although the recommended quantity of Sodium Dichromate is about 0.15 to 0.3%, occasionally when topping up, more is added.  This often results in a dark yellow to brown colour on the galvanized surface.  The darker colour will provide enhanced initial corrosion protection.

Effect / Remedy / Responsibility

This can be accepted since there is no adverse effect on corrosion control.

The galvanizer should maintain the concentration of Sodium Dichromate at about 0.15 to 0.3%.

2. ASH DEPOSITS

What is this?

Ash deposits are grey, non-metallic deposits consisting of zinc oxide that have been deposited on the hot dip galvanized coating.

Cause

Zinc oxide deposits can take place when the component is dipped or when it is removed from the bath.

Effect / Remedy / Responsibility

This can be accepted or negotiated dependent on functional requirements since the coating is normally intact underneath the ash deposits.  If required, ash must be removed by the galvanizer and the coating thickness verified for conformance to the specification requirements.

In the case of liquid conveyance pipes, all ash should be removed.

3. BARE SPOTS

What is this?

Although excluded from SANS 121:2011 (ISO 1461:2009), bare spots of about 5mm² (2.2 x 2.2mm), due to small localised flaws, are adequately protected by the sacrificial properties of zinc and will have very little effect on the service life of the coating. 

Cause

There are several causes of bare spots.  These include:

• Overdrying. If the time between fluxing and hot dip galvanizing is prolonged or the drying temperature is too high, the barrier protection provided by the flux may be lost.  This is indicated by a rusty appearance on the ungalvanized article, which can result in coating discontinuities after hot dip galvanizing.
• Excess Aluminium. A condition sometimes referred to as black spots may occur if the aluminium content of a bath becomes too high.  No trouble should be experienced if flux concentration is correct and the aluminium content of the bath is maintained below approximately 0.007%.
• Further causes are: Blowouts, flux deposits, stains and inclusions, mechanical damage, touch marks, uncoated surfaces caused – by surface contaminants, scale or sand; welds and weld spatter. See Surface Conditions 5, 15, 17, 28, 31, 32, 33 and 34.

Effect / Remedy / Responsibility

Where necessary, such spots may be repaired using one of the specified repair methods.  Gross uncoated areas are a cause for rejection.

The galvanizer should avoid overdrying and maintain the correct level of aluminium content in the kettle.

4. BLASTING DAMAGE

What is this?

Sweep blasting (done correctly) substantially increases paint adhesion and final coating appearance.  However, done incorrectly it can result in coating damage.

Cause

Incorrect nozzle pressure; nozzle angle; sweeping distance; size of abrasive and recycling of grit.

Effect / Remedy / Responsibility

This is cause for rejection as a hot dip galvanized coating will be partially or fully destroyed by excessive blasting.  Refer to the HDGASA Code of Practice.

5. BLOWOUTS

What is this?

Staining and coating defects around unsealed weld areas and vent holes.  Similar to stains caused by weeping.  See Surface Condition 26

Cause

Pre-treatment chemicals penetrating sealed overlap areas through the required vent holes and escaping during immersion in the molten zinc.  This effect tends to damage the flux coatings, causing localised uncoated areas.

Effect / Remedy / Responsibility

This can be accepted once repaired after cleaning. 

The Designer and fabricator should take this into account during the design and manufacturing phase of the project.

6. CLOGGED HOLES

What is this?

Zinc film clogging or partly bridging holes.

Cause

Molten zinc has a high surface tension and will not easily drain from holes under 8mm in diameter.

Effect / Remedy / Responsibility

This can be accepted once the item has been cleaned if required.

The Designer should make the holes as large as possible.

The removal of molten zinc over the bath by the galvanizer will reduce the likelihood of clogging.

7. CLOGGED THREADS

What is this?

Threaded components or attachments have threads clogged with zinc.

Cause

Insufficient centrifuging or poor drainage of threaded attachments on withdrawal from the galvanizing bath.

Effect / Remedy / Responsibility

This should be rejected and then cleaned by the galvanizer.  The correct centrifuging equipment or post galvanizing thread cleaning by heating and wire brushing or oversize tapping of nuts, will generally remove clogging.

If necessary, specify delivery of bolts and nuts in nutted up form.

8. DAMAGED COATINGS CAUSED BY WELDING OR NON-CONVENTIONAL FIXING METHODS DURING ERECTION

Cause

Conventional drilling and bolting after hot dip galvanizing is preferred.  Should welding or a non-conventional method of fixing be used, which results in damage to the coating, an approved repair method is necessary.

Effect / Remedy / Responsibility

Coating repair can be done by zinc metal spraying or a zinc rich paint or epoxy, providing the product conforms to the requirements of the specification.

9. DISCOLOURATION AFTER HOT DIP GALVANIZING CAUSED BY GRINDING OR OTHER RESIDUES

Cause

Material stored in contact with rusty steel or iron filings, can cause surface rust staining.

Effect / Remedy / Responsibility

This can be accepted as once the cause has been removed the stains will gradually disappear.  The Fabricator should clean if possible.

10. DISTORTION

What is this?

Distortion is the unwanted warping that occasionally becomes evident after hot dip galvanizing.

Cause

The hot dip galvanizing process occurs at a molten zinc temperature of 450°C.  This is at the lower end of the stress relieving temperature for treating steel.  Thus, any inherent rolling or welding stresses in the fabrication are likely to be released.  This may result in a dimensional change, i.e. distortion.

Effect / Remedy / Responsibility

The Designer has the following options available:  use symmetrical designs; use sections of similar thickness; stiffen unsupported thin wall sections; use preformed members with the correct minimum bend radii; use balanced or staggered welding techniques; make use of temporary braces on thin walled sections such as troughs, cylinders and angle frames.

Stress Relief assembly prior to hot dip galvanizing.

The galvanizer should avoid quenching after galvanizing.

The components can be straightened after hot dip galvanizing.

11. DRAINAGE SPIKES

What is this?

Spikes and teardrops of zinc often appear along the edge of a component after hot dip galvanizing.

Cause

The edge most likely to have these spikes is the last to leave the bath on withdrawal.  This applies particularly to complex fabrications.

Effect / Remedy / Responsibility

Drainage spikes are easily removed at the bath while still molten but any solidified spikes should be removed by careful fettling by the galvanizer prior to release.

12. DULL GREY OR MOTTLED COATING APPEARANCE

What is this?

Dull grey or mottled coatings can appear as a dark grey circular pattern, a localised dull path, or may extend over the entire surface of the component.

Cause

This appearance indicates the presence of extensive iron / zinc alloy phase growth, caused by steels with high reactive levels of Silicon and Phosphorus.

Effect / Remedy / Responsibility

Although not as aesthetically pleasing, a dull grey coating provides similar or better corrosion protection. 

13. ENTRAPMENT OF ASH

What is this?

Ash which has not been removed from the surface of the molten zinc prior to immersion of steel can be trapped on the steel surface as it is immersed and result in an uncoated surface beneath the trapped ash.

Cause

Inadequate skimming of ash from the molten zinc surface prior to dipping.

Effect / Remedy / Responsibility

On removal of entrapped ash, small uncoated surfaces shall be repaired according to the requirements of SANS 121: 2011 (ISO 1461:2009) by the Galvanizer.

Large defects greater than 0.5% of total surface area or single spots over 10cm² are a cause for rejection and require stripping and re-galvanizing.

14. FLAKING OR DELAMINATION OF COATING

What is this?

No adhesion of zinc to the steel surface or a thick, rough coating.

Cause

High phosphorus content greater than 0.02% can cause the entire coating to delaminate from the steel.

Effect / Remedy / Responsibility

The Designer should use a steel that has a phosphorus content of lower than 0.02%.

15. FLUX DEPOSITS, STAINS AND INCLUSIONS

What is this?

Flux deposits or stains from the galvanizing process may adhere to the steel or become included in the coating.  Flux residues are black, brown, grey or yellowish non-metallic deposits consisting mainly of ammonium chloride.

Cause

Flux deposits or stains may occur as a result of excessive (dusting) with ammonium chloride on withdrawal from the molten zinc.  Flux inclusions can occur when a surface flux blanket is applied to the zinc surface (wet galvanizing).  Flux blankets are normally only used for specialised processes, e.g. galvanizing tubes and fasteners.

Effect / Remedy / Responsibility

Flux deposits or stains should be removed by the galvanizer and the underlying coating measured to determine whether it conforms to the minimum requirements of the specification.

16. DISCOLOURATION OF THE PAINT COATING OVER HOT DIP GALVANIZING AFTER EXPOSURE TO THE ENVIRONMENT

Cause

Inadequate repair of a damaged surface on the hot dip galvanized coating prior to the application of a paint coating.

Effect / Remedy / Responsibility

It is the installers responsibility to ensure the correct repair materials and application procedures are used when touching up cut or welded hot dip galvanized components and prior to painting.  Where corrosion control has been compromised the job should be rejected.

17. MECHANICAL DAMAGE

What is this?

Mechanical handling or transport damage can occur, particularly with extremely thick coatings.

Cause

The use of chains, wire ropes, dragging or dropping of the component onto a hard surface, can cause mechanical damage.  This is particularly relevant with thick coatings.

Effect / Remedy / Responsibility

This can be accepted and repaired by the galvanizer or builder if necessary.

Warning labels highlighting possible damage if manhandled, should be attached by the galvanizer before the component is transported.  The use of nylon lifting slings is recommended.

18. OXIDE LINES

What is this?

Light aluminium oxide film lines on a hot dip galvanized surface.

Cause

Due to the shape and / or drainage conditions of some components, the hoist crane has stopped and started upon withdrawal of the items from the molten zinc.

Effect / Remedy / Responsibility

This can be accepted as it has no effect on corrosion resistance, with the overall appearance becoming uniform in time.

19. PIMPLES OR BLISTERS

What is this?

Pimples or blisters formed during hot dip galvanizing are usually associated with surface imperfections such as dross inclusions.

Cause

Dross pimples result from agitation of the dross layer at the bottom of the bath or from dragging material through the dross layer.  They appear as small, hard lumps on an otherwise normal galvanized surface.  Blisters may be formed by hydrogen, which is absorbed during pickling and diffused at galvanizing temperatures.

Effect / Remedy / Responsibility

This can be accepted since dross pimples represent minor disturbances in coating uniformity and do not affect corrosion resistance.  Smooth if sufficiently sharp to create the risk of injury.

The galvanizer should avoid disturbing the dross layer at the bottom by controlling immersion depth and drossing regularly.

20. REACTIVE AND NON-REACTIVE STEELS, WELDED TOGETHER

What is this?

Variations in coating thicknesses can arise when reactive and non-reactive steels are welded together.  Efforts to increase coating thickness on the less reactive steel may result in an undesirably thick and brittle coating on the most reactive steel.

Cause

This difference in coating thickness is brought about by a combination of a more reactive silicon killed steel and / or high phosphorus, resulting in a thicker coating and a less reactive aluminium killed steel, resulting in a coating thickness sometimes below that required in the specification. 

Should the galvanizer be asked to regalvanize in accordance with the specification, the resultant coating thickness on the reactive steel will be excessively thick, resulting in a brittle coating more susceptible to damage.

Effect / Remedy / Responsibility

The fabricator should select the same steel for fabricating on a component.

If need be, accept a concession request by the galvanizer when the thinner coating is possibly below specification.

21. REMOVAL OF ZINC COATING BY EXCESSIVE CLEANING

What is this?

Unless otherwise agreed, the galvanizer will limit cleaning of the final coating by mechanical means to that required in the specification.

Cause

Excessive cleaning of the coating by mechanical methods can result in uncoated areas.

Effect / Remedy / Responsibility

Care should be exercised by the galvanizer to avoid over cleaning.  If corrosion control has been compromised, i.e. exposed areas greater than tolerance; reject. 

Alternatively repair in accordance with standards.

22. ROLLING DEFECTS IN STEEL

What is this?

These defects may be broadly classified as surface discontinuities in the steel that have been elongated during rolling.

Cause

Steel may occasionally include laminations, laps, folds and non-metallic impurities, which result in slivers rolled into the metal surface.  Defects of this type are sometimes detected before or after pickling, but may only become apparent after hot dip galvanizing.

Effect / Remedy / Responsibility

This can be accepted, as minor surface defects will not adversely influence coating life. 

Surface flaws in the base material may be removed by local grinding after hot dip galvanizing followed by repair of the affected surface.

23. ROUGH COATINGS, CAUSED BY STEEL SURFACE CONDITIONS

Cause

Rough surfaces, typical of coatings on corroded steel surfaces, can be hot dip galvanized satisfactorily.  The coating will however, reflect the texture of the substrate.  Other causes of rough surfaces include uneven cold working, over pickling, a high galvanizing temperature and / or extended immersion in the molten zinc.

Effect / Remedy / Responsibility

This can be accepted as the rougher surface will produce a thicker coating and result in a longer service life.

24. ROUGH, HEAVY COATINGS CAUSED BY A ROUCH SURFACE AND / OR THE CHEMICAL COMPOSITION OF THE STEEL – “TREE BARK EFFECT”

Cause

Hot dip galvanized components showing markedly rough surfaces.  This can include coatings that have a generally rough surface and, in some cases, groove type surface configurations, “tree bark effect” caused by variations in surface steel analysis.

Effect / Remedy / Responsibility

The thicker coating produced will provide greater corrosion protection; except when the coating tends to flake off or delaminate (see surface condition 14).

25. ROUGH HEAVY COATINGS CAUSED BY INSUFFICENT CENTRIFUGING

Cause

Efficient centrifuging will generally remove excess zinc and provide a smooth and attractive exterior.

Effect / Remedy / Responsibility

Provided the steel / casting surface is reasonably smooth, correctly centrifuged articles will provide an acceptable finish.

Should the surface not be reasonably smooth; it should be rejected. 

26.STAINS CAUSED BY WEEPING

Cause

The salts from acid or flux that have penetrated porous welding or between contact surfaces during pickling, can weep after hot dip galvanizing and water quenching, providing a stained area.

Effect / Remedy / Responsibility

Weld seepage stains are not a cause for rejection.  The stains can be easily removed by means of bristle brushing.  Should the component be destined for a corrosive area, the crevice may be sealed after cleaning.

27. TIGHTHLY ADHERENT LUMPS OF ZINC ON THE INSIDE OF HEAVY WALLED STEEL PIPING

Cause

Heavy walls and thick flanges used in the manufacture of piping can act as a heat sink when immersed in molten zinc.  This effect considerably lengthens the immersion time.  Occasionally the galvanizer will remove the pipes before all the zinc has melted from the inside of the pipe.

Effect / Remedy / Responsibility

The inspector should reject this.  The galvanizer should ensure all zinc has been removed from the inside of the pipe by longer immersion times.

The item can be cleaned or repaired if acceptable to the customer.

28. TOUCH MARKS

What is this?

The zinc in the galvanizing bath should have free access to all component surfaces otherwise small uncoated or damaged areas can result.

Cause

Articles entering the galvanizing bath should not be in tight contact with each other.  Jigging wire should also be loosely attached to eliminate wire marks.  Where a component has been resting on jigging or dipping equipment, an uncoated area or touch mark could appear.

Effect / Remedy / Responsibility

The galvanizer should minimise contact between components and jig connections (loosen jigging wire).  Small components can be centrifuged.

These areas should be repaired if within allowable limits.

29. TYPICAL SPANGLED HOT DIP GALVANIZED COATING

What is this?

A typical hot dip galvanized surface is shown in the example.  The surface is silver grey in colour and not necessarily, but often has, a spangled effect (zinc crystals) in a range of sizes.

Cause

Surface appearances may vary according to the chemical composition of the steel.  Cooling rate has a direct effect on the surface brightness and spangle size.  Faster cooling usually results in a brighter coating with a smaller spangle size.

Effect / Remedy / Responsibility

Not rejectable if coating thickness within allowance limits.

30. UNEVEN DRAINAGE

What is this?

Uneven drainage results in an uneven or lumpy area on which zinc build up has occurred.

Cause

This can occur over the entire surface or in isolated areas.  Uneven drainage also includes drips on the ends of parts, runs near holes.  A cause may be high withdrawal speed and / or the galvanizing temperature being too low.

Effect / Remedy / Responsibility

This condition does not adversely affect coating performance and is acceptable. 

However, protuberances and lumps which interfere with mating surfaces are unacceptable.

32. UNGALVANIZED SURFACES CAUSED BY SCALE OR SAND

Cause

Sand on cast iron or scale on the steel surface is generally caused by the process used to form or roll the product.  A localised ungalvanized area in an otherwise continuous coating can occur if scale or sand from the moulding or rolling is not removed by acid pickling or abrasive blasting.

Effect / Remedy / Responsibility

These ungalvanized areas may occur in a linear pattern on angles, channels or other rolled products.  They can also appear on cast iron products.

Uncoated areas within the limits of 0.5% of total area or single areas of 10cm² or less can be repaired.  Larger areas are rejectable.

31. UNCOATED SURFACES CAUSED BY STEEL SURFACE CONTAMINANTS OR ENTRAPPED AIR

Cause

Residues (such as oil based paint, grease, oil or labels) on the steel surface or incorrectly positioned vent holes, can result in localised ungalvanized areas in an otherwise continuous galvanized coating.  Uncoated areas often manifest themselves as black or very dark coloured spots.

Effect / Remedy / Responsibility

To avoid uncoated surfaces, ensure all paint or grease is removed prior to hot dip galvanizing.  Make use of suitable marking pens for temporary identification.  Correctly position adequately sized vent holes.

Uncoated areas within the limits of 0.5% of total area or single areas of 10cm² or less can be repaired.  Larger areas are rejectable.

33. UNGALVANIZED AREA IN THE VICINITY OF A WELD

Cause

A localised ungalvanized area near a weld can be caused by weld slag deposit, weld porosity or weld undercut.  Oxide deposits and residues from welding are resistant to normal pickling acids and must be removed before the work is pickled and hot dip galvanized.

Effect / Remedy / Responsibility

Weld slag deposits should not be accepted prior to galvanizing and must be removed by the fabricator by means of abrasive blast cleaning.  The deposit can also be removed by proper chipping or wire brushing.

Shielded arc welding as opposed to stick welding is preferred for components which are to be hot dip galvanized.

Since corrosion control is compromised, this is rejectable; but may be repaired after negotiation.

34. WELD SPATTER

What is this?

Weld spatter is oxidised, normally spherical expelled weld metal, that is fused (or not) onto the surrounding material during welding.

Cause

Weld spatter is caused by weld pool explosions when improper welding parameters are used, or if the material is dirty or contaminated.

Effect / Remedy / Responsibility

Loosely adherent weld spatter should be removed by the fabricator prior to hot dip galvanizing.  Although not acceptable in terms of the specification, the presence of tightly adherent weld spatter after hot dip galvanizing will not affect the corrosion resistant properties of the coating.

35. WET STORAGE STAIN OR WHITE RUST

What is this?

Wet storage stain or white rust (as it is commonly called) is a white voluminous deposit that is occasionally found on the surface of a freshly galvanized coating.

Cause

Wet storage stain (zinc hydroxide) is formed on freshly galvanized surfaces which are in close contact in the presence of moisture. 

Effect / Remedy / Responsibility

Wet storage stain ceases when the cause is eliminated, i.e. the objects are separated and dried.  Once it has been removed (with a nylon bristle brush) an evaluation is possible. If the coating thickness at the affected area is equal to, or greater than the minimum required in the specification, it is not a cause for rejection.  The customer is to exercise caution during transport and storage to eliminate the susceptibility to wet storage stain.

36. ZINC METAL SPRAYED REPAIR APPLIED TO INADEQUATELY BLASTED SURFACES OR NOT WIRE BRUSHED AFTER APPLICATION

Cause

In order for zinc metal spraying to adhere on applications, the damaged galvanized surface must be adequately roughened by sweep blasting or other approved methods.  As it is difficult not to overspray, excess zinc metal spray loosely adheres to the surrounding coating.

Effect / Remedy / Responsibility

The fabricator or galvanizer must prepare the surface for repair by roughening the surface by sweep blasting or some other approved method.  Loosely applied zinc metal sprayed coating at the perimeter of the repair should be removed by wire brushing.  If not removed, there is no compromise in the corrosion resistance.

37. ZINC SPLATTER

What is this?

Splashes and flakes of loosely adherent zinc, caused by moisture on the steel surface when hot dip galvanizing.

Cause

When hot dip galvanizing on unusually deep fabrications by double dipping, moisture on the surface of the steel contacts with the molten zinc causing splashes of zinc to loosely adhere to the already hot dip galvanized surface.

Effect / Remedy / Responsibility

The loosely adherent zinc splashes are easily removed and should be prior to release.  An experienced galvanizer can ensure the coating overlap on double end dipped surface, is not visible.

Volume 10, Issue 3: August 2013 (55)

1. 2013 Hot Dip Galvanizing Awards (Overall and Infrastructural & Community DevelopmentCategory Winner): HA Mofutho Pedestrian Bridge.
2. 2013 Hot Dip Galvanizing Awards (Joint Architectural Category Winner): 10111 RadioControl Centre.
3. 2013 Hot Dip Galvanizing Awards (Joint Architectural and Duplex Coating Systems CategoryWinner): House in Rooi Els
4. 2013 Hot Dip Galvanizing Awards (Mining & Industry Category Winner): Ndlovu Roll OverProtection Structure and Falling Object Protection Structure.
5. 2013 Hot Dip Galvanizing Awards (Innovation Category Winner): Solar Trees at WaterfallEstates.
6. 2013 Hot  Dip  Galvanizing  Awards  (Other  Submissions):  Nellmapius  Bridge,  Waterfall Estates Clubhouse, Ncome Museum Pedestrian Spiral Bridge, N17 Light Masts, Canopies and Toll Booths, Sea Rogue Weapon System, General Motors South Africa, Construction of Back of Berth Pipe Racks, Tilt-Up Heavy Duty Security Walling, Tshipi Borwa Mine Stock Pile Tunnels, Medupi Power Station: Ash & Coal Terrace, Civin Road Bridge, The Grass Roll Saver.
7. 2013 Hot Dip Galvanizing Awards: Judges
8. On the Couch …. John Abbott
9. Technical: Abrasive blast cleaning; a compulsory pre-treatment for different coatings applied to a steel substrate
10. Bob’s Banter: The simple things of project communications
11. Cable Ladders and Trays: The need for strength testing of cable ladders
12. Education: The new wall chart
13. Education: Three day Galvanizers Inspectors Course
14. News: Hot dip galvanized steel quality
15. News: South African steel fabrication industry bleeds as major clients procure abroad

Volume 10, Issue 2: May 2013 (54)

1. Fasteners: Developments in Construction Boltin
2. Fasteners: Hot dip galvanizers hit by imports.
3. Fasteners: Fastener availability matrix and participating fastener suppliers.
4. General: Corrosion protection of a giant cross that protects Van Staden Bridge.
5. Case History: Lion’s den, disused old zoo, Groote Schuur Estate, Cape Town
6. Misconceptions: When ordering steel that requires to be galvanized after fabrication, all thatis required is to specify a quality steel grade and no problems will be encountered by the galvanizer in achieving the required coating standard.
7. Technical: From decision to receipt
8. Bob’s Banter: Natural networking can achieve a sustainable business organisation.
9. Duplex Coatings: Cape Town’s MyCity bus shelters
10. Obituary: Len Avellini and Andrew Dippenaar
11. Duplex Coatings: Preparing a hot dip galvanized surface for painting.
12. Education: 3 Day Galvanizers Inspectors Course
13. Education: The new wall chart
14. Education: New coating thickness gauge with enhanced features.
15. Education: Corrosion Economics – The effect of corrosion and corrosion protection costs on business profitability and sustainability.
16. General: 2013 Hot dip Galvanizers Association Golf Day
17. General: Why would anyone want to paint a fence?
18. On the Couch ….  Nina Saunders

Volume 10, Issue 1: February 2013 (53)

1. The world of hot dip galvanizing around us: Cliffwalk at the Capilano Suspension Bridge, Vancover, Canada.
2. The world of hot dip galvanizing around us: Jet Blue Park, Fort Myers, FL United States.
3. The world of hot dip galvanizing around us: New World Centre Soundscape, Miami Beach, Florida.
4. The world of hot dip galvanizing around us: Contemplay Pavilion; Montreal, Quebec.
5. The world of hot dip galvanizing around us: Light Chamber at the Denver Judicial Centre, Denver, Colorado.
6. The world of hot dip galvanizing around us: Knox County Bridge revamp, Knox County, Ohio.
7. The world of hot dip galvanizing around us: Dali Museum, St Petersburg, Florida.
8. The world of hot dip galvanizing around us: Hambro Modular Parking System, St Lambert, Quebec.
9. The world of hot dip galvanizing around us: Reliant Stadium, Houston, TX, United States.
10. The world of hot dip galvanizing around us: Burlingame Fred Meyer Remodel, Portland, OR, United States.
11. The world of hot dip galvanizing around us: Indianapolis Motor Speedway, Indianapolis, Indiana.
12. The world of hot dip galvanizing around us: Twister Roller Coaster, Stockholm Sweden.
13. The world of hot dip galvanizing around us: Tanzania Bridge, Tanzania, Africa.
14. The world of hot dip galvanizing around us: Park Lake State School, Australia.
15. The world of hot dip galvanizing around us: Noosa Junction Station, Australia.
16. The world of hot dip galvanizing around us: Milson Island Indoor Sports Stadium, Australia.
17. The world of hot dip galvanizing around us: Manuele Engineers Steel Facade Building, Australia
18. The world of  hot  dip  galvanizing  around  us:  Craigieburn  Train  Maintenance  Facility, Australia.
19. The world of hot dip galvanizing around us: Futsal Stadium, Australia.
20. The world of hot dip galvanizing around us: Coca-Cola Amatil Distribution Centre, Australia.
21. The world of hot dip galvanizing around us: Glacier Perito Mereno, Latin America.
22. The world of hot dip galvanizing around us: Cataratas Iguazu Waterfalls Viewing Platform, Latin America.
23. LatinGalva – Santiago, Chile
24. General: Ten years at the Association
25. Misconceptions: Steel must be abrasive / sand blast cleaned prior to hot dip galvanizing.
26. True or False?
27. Education: Three day Galvanizers Inspectors Course
28. Bob’s Banter: Using employees as resources is not developing people as assets.
29. Member News: Alan Oswald, new Managing Director of Robor Galvanizers
30. On the Couch …. Riaan Louw

Volume 9, Issue 3: August 2012 (52)

1. Architectural Hot Dip Galvanizing: An architect’s perspective on using hot dip galvanized steel in structural designs.
2. Architectural Hot Dip Galvanizing: House Taylor, Ballito Bay.
3. Architectural Hot Dip Galvanizing: House Rooi Els.
4. Architectural Hot Dip Galvanizing: Rondebosch on Main Shopping Centre.
5. Architectural Hot Dip Galvanizing: Waterfall Country Estate / Village.
6. Architectural Hot Dip Galvanizing: House Spooner – Hout Bay.
7. Architectural Hot Dip Galvanizing: Construction of a new 10111 Radio Control Centre in PortElizabeth.
8. Architectural Hot  Dip  Galvanizing:  Hot  dip  galvanizing  for  general  and  architectural purposes.
9. Cable Ladders and Wire Ways: “Megabow” – the long spanning, cost effective, double sided, modular cable ladder.
10. Cable Ladders and Wire Ways: All galvanized power skirting.
11. Bob’s Banter: Consider reinventing, instead of reengineering, your business for survival and success.
12. News: The new Elcometer 456 offers …
13. Education & Training: Hot dip galvanized fasteners
14. Education & Training: Report back from Intergalva 2012
15. Education & Training: Environmentally friendly flux
16. Members News: Robor makes soccer goal posts for Dreamfields project in Tembisa
17. On the Couch …. Jim Baggett

Volume 9, Issue 2: June 2012 (51)

1. Masts &  Poles:      Unique  patented  steel  utility  pole  developed  for  electrical  and communications industries.
2. Water Storage: Power stations and mines benefit from reliable, cost effective water storage tanks.
3. Heat Exchangers & Cooling Fans: The benefit of a correctly sized cooling tower.
4. Duplex Coatings: Duplex system with powder paint.
5. Duplex Coatings: Duplex coating of the Ndlovu Roll Over Protection Structure (ROPS) and the Falling Object Protection Structure (FOPS)
6. Duplex Coatings: Communicate to achieve specification requirements.
7. On the Couch …. Alan Lamb
8. Technical: Galvanic Corrosion
9. Education: 3 Day Galvanizers Inspectors Course
10. Education: Renewable energy is a large part of the green movement.
11. Bob’s Banter: Black Swans
12. Coating Report: Evaluation of hot dip galvanized structural steel subjected to a fire at the waste collection and sorting facility, IDZ – East London

Volume 9, Issue 1: March 2012 (50)

1. Fasteners: Fastener availability matrix and participating fastener suppliers
2. Fasteners: Placing hydrogen embrittlement (HE) of fasteners into perspective.
3. Fasteners: Roof fixings in aggressive environments
4. Fasteners: The changing landscape for fastener manufacturers.
5. Fasteners: Let’s torque tightening!
6. Fasteners: Get a grip
7. Fasteners: A secure strategy for growth
8. Fasteners: Report on sample bolts from Medupi
9. Bob’s Banter: Turn your creative staff into skunks to keep them away from predators
10. Contribution from South America: Motivation and methodology of hot dip galvanizing steel railway sleepers for Vale Do Rio Doce, Brazil
11. Technical: Beware of hot dip galvanizing structural steel with extremely high phosphorus!
12. Technical: What is Cathodic Protection (CP) and what it isn’t
13. Duplex Coatings: Protecting your steel investment
14. Education: National Environmental Management Workshop
15. Zinc Metal Spraying: New thermal metal spray gun
16. Member’s News: Galvspin Galvanizers automated centrifuge plant
17. Member’s News: Robor claims Deloite Best Company to Work For title once again
18. On the Couch …. Linda Ness

Volume 8, Issue 4: November 2011 (49)

1. The World of Hot Dip Galvanizing Around Us: The use of hot dip galvanizing in China’s high speed rail system
2. The World of Hot Dip Galvanizing Around Us: Use of galvanized rebar in Chile
3. The World of Hot Dip Galvanizing Around Us: Use of duplex systems in Chile
4. The World of Hot Dip Galvanizing Around Us: De Waterlelie Community School – safety and durability on a higher plane
5. The World of Hot Dip Galvanizing Around Us: Solana Solar Power Plant in the USA
6. The World of Hot Dip Galvanizing Around Us: Bicycle Apple Garage – Netherlands
7. The World of Hot Dip Galvanizing Around Us: Asia Pacific General Galvanizing Association
8. Bridges: Pedestrian Bridges
9. Bridges: The opening of Intombe Bridge
10. Bridges: Intombe Pedestrian Bridge
11. Bridges: Restoring Cape Town’s long standing pedestrian bridges
12. Duplex Coatings: Duram’s water based duplex system (Advertorial)
13. Duplex Coatings: Coega Harbour rail yard
14. Bob’s Banter: Companies can realise their potential by using their employees’ inbred talents
15. Education: 3 Day Galvanizers Inspectors Course
16. On the Couch .… Professor Denis Twigg

Volume 8, Issue 3: August 2011 (48)

1. Awards Event: 2011 Hot Dip Galvanizing Awards. Winners and all Submissions
2. Cable Ladders & Trays: More than just bent metal
3. Cable Ladders & Trays: General and continuous hot dip galvanized unistrut sign support Channels
4. Artistic Works: Artistic works of art that require durability while maintaining their desirability.
5. Bob’s Banter: Problem solving means reaching destinations, not just reading signposts
6. Education: 3 Day Galvanizers Inspectors Course
7. New Products: Elcometer sets new standards for coating inspection data management
8. General: The real protection at Jozini Private Bush Lodge is hidden!
9. On the Couch .… Rob White

Volume 8, Issue 2: June 2011 (47)

1. Tubes and Pipes:  Ensure that the specification is correct when required general hot dip galvanized products!
2. Masts & Poles: Hot dip galvanized mild steel sleeved high rise masts (Central Sports Complex, City of Umhlathuze – Richards Bay)
3. Water Storage: Pressed Steel Sectional Water Tanks
4. Thermal Metal Spraying: Seam spraying of pre-coated ERW tube
5. Bob’s Banter: Problem solving means reaching destinations, not just reading signposts
6. Case Study: Simonstown Utility Gantry
7. Duplex Coatings: Painting hot dip galvanized steel
8. Education: The “unsung” but extremely necessary hot dip galvanizing standard (SANS 14713:2011)
9. Education: Revision of EN ISO 14713 (Courtesy of the Galvanizers Association – UK)
10. Education: Quench additive for hot dip galvanizing – a new approach
11. Member News: Transvaal Galvanisers
12. Coating Report: Microbiologically influenced corrosion of water pipes
13. General: Zinc: the element of human development
14. On the Couch …. Nick Proome

Volume 8, Issue 1: March 2011 (46)

1. Fasteners: Evaluation of concrete screw-bolts
2. Fasteners: An update development in the fastener industry
3. Fasteners: Failure of roof fixing screws – Case Study
4. Fasteners: Gautrain uses hot dip galvanized “Lindapter” structural fixings
5. Fasteners: Fastener availability matrix and participating fastener suppliers
6. Continuous Hot Dip Galvanized Sheet: Development of the LSFB industry in Southern Africa
7. Continuous Hot Dip Galvanized Sheet: Fasteners and lightweight steel structures
8. Continuous Hot Dip Galvanized Sheet: What is a spangle?
9. Galfan Coated Wire: Improving the effect of a galvanized coating on wire to protect steel products
10. Thermal Metal Spraying: Medupi Chimneys – thermal zinc metal spray of plate girders – platform 205m
11. On the Couch …. Anna Loubser
12. Stephen’s Corner: “It only works when you don’t need it”
13. Bob’s Banter: Co-operation with conflict may be better than competition
14. Duplex Coatings: The case for duplex coating “systems” must continue.

Volume 7, Issue 4: November 2010 (45)

1. The World of Hot Dip Galvanizing Around Us:      The Asia Pacific General Galvanizing Association (APGGA)
2. The World of Hot Dip Galvanizing Around Us: From the USA …
3. On the Couch: With Charles Taylor
4. Thermal Metal Spraying: The alternative metallic coating corrosion control system
5. Thermal Metal Spraying: Anti corrosive finishing
6. Thermal Metal Spraying: Zinc and aluminium metal spraying
7. Greening of the Hot Dip Galvanizing Industry: Advanced Galvanising leads the greening of the hot dip galvanizing revolution
8. Greening of the Hot Dip Galvanizing Industry: Galvaglow goes green
9. Bob’s Banter: Natural laws show how value can be added
10. Stephen’s Corner: “It only works when you don’t need it!”
11. Duplex Coatings: DDL Equipment – dock levellers: an update
12. Education: Revised 3-day Galvanizers Inspectors Course for 2011
13. Duplex Coatings: The case for duplex coating on a hot dip galvanized substrate in an aggressive (C5) environment – the ultimate challenge for the paint industry!

Volume 7, Issue 3: August 2010 (44)

1. Architectural  Hot  Dip  Galvanizing: What  every  architect  should  know  about  hot  dip galvanizing deemed for use in architectural steelwork!
2. Architectural Hot Dip Galvanizing: Moses Mabhida Railway Station
3. Architectural Hot Dip Galvanizing: Hot dip galvanizing goes “Out of Africa”
4. Architectural Hot Dip Galvanizing: Using an orbital sander can improve the appearance of the hot dip galvanized coating
5. Architectural Hot Dip Galvanizing: Re-galvanizing a mooring chain results in an exponentialincrease in service life!
6. Case Study: Stratfords Guest House and Conference Centre
7. Cable Ladders & Trays: Gautrain Cable Management Systems
8. Cable Ladders & Trays: Evaluation of hot dip galvanized cable ladders at Sasol Synfuels, Secunda
9. Cable Ladders & Trays: Hot dip galvanizing – the bookmaker’s firm favourite!
10. Bob’s Banter: Lessons on business ethics from cleaner fish
11. Stephen’s Corner: “It only works when you don’t need it!”
12. Duplex Coatings: DDL Equipment – dock levellers: an update
13. Education: Association publications
14. Member’s News: Eureka Project completed in record time thanks to new Robor Hybrid Structure
15. Member’s News: New Affiliate Member – CIS
16. On the Couch: With Geoff Colloty

Volume 7, Issue 2: June 2010 (43)

1. Tubes & Pipes: Lula and Cable-Lock Pipe: A dual force at Dilkong Chrome Mine
2. Tubes & Pipes: The development of S355 tube
3. Tubes & Pipes: Recently launched Grade 355 tubes – a compelling engineering solution for many applications
4. Masts & Poles: Sign gantries on R300 hot dip galvanized!
5. Masts & Poles: IPM projects and emphasis on straightening after hot dip galvanizing
6. Heat Exchangers: Hot dip galvanized air coolers at an apple farm – Case Study
7. Heat  Exchangers:   Operating   and   maintenance   instructions   for   typical   evaporative condensers  and  industrial  fluid  coolers  (in  terms  of corrosion  and  specifically  hot  dip galvanizing)
8. Water Storage: Fog harvesting yields fresh water for isolated communities
9. Stephen’s Corner: “It only works when you don’t need it!”
10. Stephen’s Corner: Deep tunnel sewage systems pre-cast concrete piping
11. Stephen’s Corner: Tailings  Storage facility uses  hot  dip galvanized  reinforcement  for sustainability!
12. On the Couch: Hennie de Clercq
13. Duplex Coatings: The house in Rooi Els
14. Education & Training: Corrosion Rish Management Courses
15. Bob’s Banter: The logic of collaborative partnerships
16. Member’s News: Galvaspin introduces a zinc thermal spraying facility at their works in Port Elizabeth
17. Member’s News: Robor achieves 1 000 000 man hours free of disabling injuries!
18. HDGASA: Zinc may improve effectiveness of HIV drugs

Volume 7, Issue 1: April 2010 (42)

1. Fastener Availability Matrix and Participating Fastener Suppliers
2. Fasteners: SANS 1273 – Setting a New Standard for Roofing Fasteners
3. Continuous Wire  Galvanizing:  The  Introduction  of  Galfan  Coated Wire  at  Cape  Gate, Vanderbijlpark.
4. Continuous Wire Galvanizing: SANS 675: 2009 Zinc Coated Fencing Wire, has been revised
5. 2010 Soccer World Cup Stadia: Reviewing the Corrosion Protection Provided by Hot Dip Galvanizing of the Stadia for the 2010 Soccer World Cup – Moses Mabhida Stadium, Cape Town Stadium, Port Elizabeth Stadium and Soccer City
6. 2010 Soccer World Cup Stadia: Innovative Use of Mentis Grating at Soccer City
7. Education and Training: The New Features for the Elcometer 456 Coating Thickness Gauge
8. Case Study: Newlands Rugby Stadium – Railway Stand
9. Bob’s Banter: Like Bacteria, the Business Community needs a Common Immune System
10. Hot Dip Galvanized Rebar: The Merits of using Hot Dip Galvanized Steel Reinforcement in Concrete Structures
11. Hot Dip Galvanized  Rebar:  Professor  Stephen  R  Yeomans  Presented  a  Series  of Presentations and Seminars in South Africa in February 2010
12. Wamosha: Capricon Park – “Are the Two Coatings the Same?”
13. Member’s News: Robor Restructuring Enhances Offering
14. Member’s News: Armco Galvanizers Hot Dip Galvanizes Steel for the “Ring of Fire” a Soccer City, Johannesburg
15. Member’s News: Galvadip Chosen as Hot Dip Galvanizer for FIFA World Cup Soccer Stadium Turnstiles

Volume 6, Issue 4: November 2009 (41)

1. The World of Hot Dip Galvanizing Around Us: The European Galvanizing Awards
2. The World of Hot Dip Galvanizing Around Us: From the USA
3. The World of Hot Dip Galvanizing Around Us: Sydney Desalination Plant – shoring up the future
4. Guest Writer: Utilising ISO standards and best engineering practices in order to ensure long term cost effective corrosion control – Gerald Haynes
5. Greening of the hot dip galvanizing industry: Smoke-free / low-smoke flux – STT
6. Greening of the hot dip galvanizing industry: The treatment of acidified rinse water in hot dip galvanizing plants – Robor Galvanizers
7. Greening of the hot dip galvanizing industry: Environmentally friendly fluxes and passivation systems
8. Greening of the hot dip galvanizing industry: Reviewing the hot dip galvanizing process and risk analysis
9. Greening of the hot dip galvanizing industry: Metsep’s acid regeneration process – Making acid last longer!
10. Obituary: John Leitch
11. Greening of the hot dip galvanizing industry: Environmentally sensitive since 1981 – Cape Galvanising
12. Education: Measuring coatings on metal substrates (part 6)
13. On the couch with Heike van Eijden of Galvadip
14. An innovative system for the joining of steel piping

Volume 6, Issue 3: August 2009 (40)

1. Awards: National Library – Overall & Architectural Category Winner
2. Awards: Bosal House of Irrigation – Infrastructural Development Category Winner
3. Awards: Potsdam Wastewater Treatment Works Settling Tanks – Duplex Coating Systems Category Winner
4. Awards: Steam Condensing Radiator – Mining & Industrial Category Winner
5. Awards: Reichenau Mill Restoration Project – Community Development Category Winner
6. Awards: Moroccan Grand Prix – Export Category Winner
7. Awards: Nelson Mandela Museum
8. Awards: Table Bay Hotel
9. Awards: Sweet Valley Primary School
10. Awards: Sassi Design
11. Awards: Lorbrand / DRA DMO
12. Awards: Workshop at Klipspruit Coal Mine
13. Awards: Ground Based Global Positioning Systems
14. Awards: Eshowe Taxi Rank
15. Awards: Bisi Pedestrian Bridge
16. Bob’s Banter: Statemanship and business leadership have much in common
17. Case Study: An evaluation of hot dip galvanized cable ladders after being exposed for some 25 years at a Cape Town Petro-Chemical Plant
18. Education: Revised SANS 121 (ISO 1461:2009)
19. Education: Steel Protection by Hot Dip Galvanizing & Duplex Coating Systems (revised edition)
20. Education: Measuring coatings on metal substrates (part 5)
21. On the couch with Anni Ramkisson
22. Misconceptions: If you require a thicker hot dip galvanized coating you should specify it a C4 or C5 (in terms of ISO 9223) hot dip galvanizing!

Volume 6, Issue 2: June 2009 (39)

1. Water Storage: Water challenges in a changing climate
2. Tribute to Walter Barnett
3. Galvanizer’s Corner: A day in the life of a hot dip galvanizer!
4. 2009 Hot Dip Galvanizing Awards
5. Golf Day: The HDGASA 2009 Golf Day
6. Duplex Coatings: The ‘Rolls Royce’ System
7. Zinc is Green: Life-cycle assessment recognises the green benefits of zinc
8. Guest Writer: Methods of preventing hydrogen embrittlement in hot dip galvanized high strength steel fasteners – Spencer Erling
9. Education: Zinc rich paint and epoxies versus hot dip galvanizing
10. Education: Measuring coatings on metal substrates (part 4)
11. Bob’s Banter: Achieving our desired future means managing the unexpected
12. Coating Report: Coastal Education and Visitors Centre at Nahoon Point
13. On the couch with Association staff – the rest of the team
14. Wamosha: Assessment of “rusted” hot dip galvanized floor gratings
15. Corrosion: Differential aeration or “necking corrosion” re-explained
16. Member’s Corner: Galvspin Galvanizers
17. Member’s Corner: Robor Galvanizers

Volume 6, Issue 1: March 2009 (38)

1. 2009 Hot Dip Galvanizing Awards
2. Awards: Confessions of an “Awards Junkie”
3. Fasteners: Strength designations, metric bolts
4. Fasteners: Fastener availability matrix and participating fastener suppliers
5. Misconceptions: Smooth  and  polished  surfaces  are  a  standard  feature  of  all  hot  dip galvanized surfaces. True or False?
6. Handrails: “Although understandably not always practical, minimizing galvanizing coating repair is a function of proper design and good fabrication techniques!”
7. Handrails: Zinc’s second defense mechanism – cathodic or sacrificial protection!
8. Bob’s Banter: Patterns and trends are more important than detail and data
9. Duplex Coatings: Paint at your peril!
10. Specification and application variables – not critical for successful hot dip galvanizing
11. On the couch with Yvonne Onderweegs
12. Coating Report: The consistency and uniformity of hot dip galvanizing versus zinc metal spraying or spray paint
13. Galvanizing Repairs: Zinc rich coatings for repair purposes
14. Wamosha: Evaluation of roof sheet discolouration
15. Education: Measuring coatings on metal substrates (part 3)
16. Member’s Corner: New galvanizing alloy available in South Africa
17. Member’s Corner: New  galvanizing  plant  gets  top  of  the  range  heating  and  control equipment
18. Member’s Corner: Phoenix elephant comes to Cape Town en route to Europe
19. Member’s Corner: Voigt & Willecke 2009, bigger and better..

Volume 5, Issue 4: November 2008 (37)

1. Tubes, Pipes & Scaffolding: Giuricich Coastal Projects goes galvanized
2. Tubes, Pipes & Scaffolding: Structural tube – a short history
3. Water Storage: 25 years of bulk water storage
4. Water Storage: Benefits of the Botank Steel Water Storage Reservoir
5. Technical differences  between  general  or  batch  type  and  continuous  sheet  hot  dip galvanizing
6. Duplex Coatings: Duplex coated Lula pipe is used to successfully overcome corrosive water problems
7. Guest Writer: Performance testing of protection systems – Darelle Janse van Rensburg
8. Duplex Coatings: Understanding quality control and quality assurance
9. Duplex Coatings: Duplex systems and why they are necessary
10. Bob’s Banter: Like Michelangelo, we should be smart when it comes to arguing
11. Measuring coatings on metal substrates (Part 2)
12. Member’s Corner: Charlene Bossert of Bulldog Projects passes NACE
13. Member’s Corner: Galvadip has their 25th birthday!
14. Coating Report: Guard rails on the Kamanjab – Omagange Road in Namibia
15. On the couch with Jeremie Malan
16. Wamosha: Bread bakery exchanger coil investigation
17. Misconceptions: The world is running out of zinc.
18. Zinc outlook for 2008 and 2009
19. Walter’s Corner: Some experiences from the past
20. Case Study No. 16/2008: RaiseTech W50 mining drilling machine

Volume 5, Issue 3: August 2008 (36)

1. Tubes, Pipes & Scaffolding: Giuricich Coastal Projects goes galvanized
2. Tubes, Pipes & Scaffolding: Structural tube – a short history
3. Water Storage: 25 years of bulk water storage
4. Water Storage: Benefits of the Botank Steel Water Storage Reservoir
5. Technical differences  between  general  or  batch  type  and  continuous  sheet  hot  dip galvanizing
6. Duplex Coatings: Duplex coated Lula pipe is used to successfully overcome corrosive water problems
7. Guest Writer: Performance testing of protection systems – Darelle Janse van Rensburg
8. Duplex Coatings: Understanding quality control and quality assurance
9. Duplex Coatings: Duplex systems and why they are necessary
10. Bob’s Banter: Like Michelangelo, we should be smart when it comes to arguing
11. Measuring coatings on metal substrates (Part 2)
12. Member’s Corner: Charlene Bossert of Bulldog Projects passes NACE
13. Member’s Corner: Galvadip has their 25th birthday!
14. Coating Report: Guard rails on the Kamanjab – Omagange Road in Namibia
15. On the couch with Jeremie Malan
16. Wamosha: Bread bakery exchanger coil investigation
17. Misconceptions: The world is running out of zinc.
18. Zinc outlook for 2008 and 2009
19. Walter’s Corner: Some experiences from the past
20. Case Study No. 16/2008: RaiseTech W50 mining drilling machine

Volume 5, Issue 2: June 2008 (35)

1. Energy efficient, resource sustaining hot dip galvanizing facility – GB Galvanizing
2. The hot dip galvanizing industry is acknowledged at the Africa Energy Awards
3. Fastener availability matrix and participating fastener suppliers
4. The ‘ins’ and ‘outs’ of hydrogen embrittlement
5. In light  of  the  fluctuating  steel  price  and  the  restrictive  suppliers  quote  affecting  the availability of fasteners, early ordering is even more important
6. Focusing on hot dip galvanized fasteners
7. Can hot dip galvanizing cause stripping of nut threads?
8. Times are a changing
9. Bob’s Banter: Being happy at work
10. Duplex Coating: Correct paint selection for a duplex coating system
11. Walters Corner: The hot dip galvanizing of threaded articles
12. Guest Writer: Strategy for a co-operative effort to reduce zinc consumption for galvanizing reactive steels
13. Coating Report: Extension to the cold storage facility – Maydon Wharf, Durban
14. On the couch with: Pieter Mathews
15. Galvanizing Failures: Inconcise specifications reduce overall coating performance!
16. Misconceptions on pricing of hot dip galvanizing
17. Misconceptions: Hot dip galvanizing of high strength fasteners is not recommended, due to the propensity for fracture as a result of hydrogen embrittlement. True or false?

Volume 5, Issue 1: March 2008 (34)

1. 2008 Hot Dip Galvanizing Awards Evening, Call for Nominations
2. The World of Hot Dip Galvanizing  Around Us: Geelong  Carousel Pavilion –  Geelong, Australia
3. The World of Hot Dip Galvanizing Around Us: Charlotte Douglas International Airport, USA
4. The World of Hot Dip Galvanizing Around Us: 7th Avenue LRT Refurbishment, Canada
5. The World of Hot Dip Galvanizing Around Us: The Tip Top Building Renovation, USA
6. The World of Hot Dip Galvanizing Around Us: Metcalf Energy Centre, USA
7. The World of Hot Dip Galvanizing Around Us: Rapid Aerostat Initial Deployment System, Iraq and Afghanistan
8. 2008 Hot Dip Galvanizing Conference
9. Duplex Coatings: Surface preparation for painting hot dip galvanized steel
10. Duplex Coatings: Corrosion protection systems – an environmental comparison
11. Coating Report: The effect of the insulation fixing wires on the hot dip galvanized purlins on the seaward side of the Assembly Hall at Cranston College – KZN
12. Guest Writer: The Pool Guy – Russell Thompson
13. Walter’s Corner: The Diversity of Zinc
14. Misconceptions: As is the case with all protective coatings, discontinuations and thin areas on an applied hot dip galvanized coating will inevitably lead to disaster in all but the most benign environments
15. Galvanizing Failures: Report on site visit to Komatipoort Farms
16. Hot dip galvanizing making a difference at grassroots level
17. Personality Profile: Entrepreneur extraordinaire – Mokena Makeka
18. Bob’s Banter: Team work does not have to be an illusion

Volume 4, Issue 4: November 2007 (33)

1. Armco Superlite – supplying water reservoirs to meet Africa’s needs.
2. Hot dip galvanized window frames in Cape Town houses a popular necessity.
3. Hot dip galvanizing for general and architectural purposes.
4. Hot dip galvanizing goes POTTY…..
5. Hot dip galvanized fasteners, this and that …….
6. Impala Nut and Bolt
7. Proudly South African Tel-Screw products.
8. Types of fasteners and availability matrix.
9. Misconceptions: For  long  term  corrosion  protection,  all  that  is  required  is  to  specify “galvanizing”   and  satisfactory  results  will  be   achieved  in  most  environments  and applications. True or false?
10. Hot dip galvanized Mentis Rectagrid floor grating.
11. The Vitagrid® fully serrated grating gains galvanizing popularity.
12. Duplex coatings: Single coat duplex system.
13. Duplex coatings: Application requirements of a duplex system for the “man in the street”.
14. Duplex coatings: A “very novel duplex coating” system.
15. Walter’s Corner: Durability of hot dip galvanizing and duplex protection.
16. Guest writer: Situational awareness: a necessary skill for the modern world, by Bob Andrew.
17. Coating report: Electro-galvanized (electro plated) expanded metal used in the manufacture of sound baffles at a plant near Atlantis, Western Cape.
18. Zinc speeds recovery from pneumonia.
19. Members’ news: The 7th Asian Pacific General Galvanizing Conference.
20. Members’ news: News from Zincor.
21. Personality profile: Creative duo – Eerhard Huizinga and Jane Durand.
22. Galvanizing failures: All galvanized coatings are not necessarily the same.
23. Coating inspectors course.
24. Case history No. 14/ 2007: Evaluation of the hot dip galvanized coating at Pentrich sub- station, Mkondeni, Pietermarizburg.

Volume 4, Issue 3: August 2007 (32)

1. 2007 Eskom Hot Dip Galvanizing Awards, featuring overall winner, category winners and submissions.
2. Materials/coatings used in the utility pole market – summary of a 2006 survey.
3. Coating inspectors’ validity card.
4. How to choose the correct material or coating for utility poles – a layman’s comments.
5. Industrial Poles and Masts (Pty) Ltd. – largest steel street light pole manufacturer in South Africa.
6. Sign gantry coatings – but what about the maintenance!
7. Guest writer: Don’t be worried by pessimism; it can provide the key to a better future, by Bob Andrew.
8. Duplex report: Duplex system in a mild to moderately aggressive environment.
9. Walter’s Corner: Corrosion control of threaded articles.
10. Coating report: Sweep blasting to prepare hot dip galvanizing for paint is a great way of achieving paint adhesion but follow the rules……..
11. Misconceptions: Sweep blasting of hot dip galvanized surfaces prior to painting should beavoided as this invariably results in delamination of the zinc coating from the underlying steel surface. Sweep blasting also removes a portion of the valuable zinc coating. True or false?
12. Members’ news: Mentex Expanded Metal goes ‘green’ with LVG plants. Cathodic protection: by CTC
13. Personality profile: George Elphick, to date ……

Volume 4, Issue 2: June 2007 (31)

1. Stadiums: 2010 and all that.
2. Athlone Stadium east stand arch.
3. Blue Bulls are “galvanized” into action at the dying moments and win the Super 14 final from the Sharks.
4. Constantia Glen winery.
5. Fan manufacturer chooses hot dip galvanizing over paint for corrosion protection.
6. Building the future: water sustainability, durability and economics.
7. Some interesting applications from the American Galvanizers “Galvanizing Awards 2001”.
8. Workshop: regulations in Europe.
9. Some global perspectives on hot dip galvanizing.
10. Guest writer: Like the slime mould, mergers, acquisitions and unbundling should be seen as part of a company’s life cycle, by Bob Andrew.
11. Duplex coating report: Preparing hot dip galvanized steel for painting – a duplex system.
12. Coating report: Understanding one of the criteria for measuring the hot dip galvanized coating thickness in terms of SANS 121 (ISO 1461).
13. Personality profile: Louis H. van
14. Walter’s Corner: How long does “galvanizing” last?
15. “Extreme milkshake drinking” – a report on the freak spring tides’ destruction of Lazy Shades in Margate.
16. Misconceptions: When ordering steel that requires to be galvanized after fabrication, all that is required is  to  specify a  quality  steel  grade  (i.e.  300WA)  and  no  problems  will  be encountered by the galvanizer in achieving the required coating standard. True or false?
17. Members’ News: Pro-Galv commences business.
18. Zinc market update.
19. Robor adds Africa’s deepest kettle to widest and one of the longest.
20. Coating inspectors course – now with CPO points.
21. ihAsian Pacific General Galvanizing Conference.
22. Mexico launches zinc-enriched milk.
23. HDGASA Golf day- pictorial.

Volume 4, Issue 1: March 2007 (30)

1. Southern Africa Light Steel Frame Building Association (SASFA).
2. Introduction to ARTF and Roof Technology Services (RTS) – a company profile.
3. Durability of galvanized sheet in light steel frame buildings.
4. The family of zinc, zinc-aluminium and duplex coated coiled sheeting.
5. Durability of hot dip galvanized sheeting exposed to general atmospheric conditions.
6. Major new player in lightweight steel frame building industry.
7. The fasteners required for light weight steel framed buildings.
8. Andrew Mentis plays it safe at Marion Island.
9. Van Ryssen Dam, Phalaborwa.
10. Focus on security.
11. Wire galvanizing specifications revised.
12. Bread is now fortified with zinc!
13. Duplex coatings: A life cycle costing analysis comparing painted steel, hot dip galvanizing and duplex coating systems.
14. Duplex coating report: Duplex coated verandah columns at Parklands Shopping Centre, Cape Town.
15. Coating report: Wet storage stain and subsequent red rust to the hot dip galvanized sheeting on a slag crushing plant.
16. Case study: Moma Sands project, Mozambique.
17. Personality profile: Busisiwe Christina Mpontshame.
18. Misconceptions: A hot dip galvanized coating can be successfully used at temperatures up to 419°C, which is the melting point of zinc. True or false?
19. Walter’s Corner: The hot dip galvanizing industry is alive and well.

Volume 3, Issue 4: November 2006 (29)

1. 2006 Eskom Hot Dip Galvanizing Awards – the evening in pictures.
2. The use of hot dip galvanizing in general mining.
3. Gold mining: Moab Khotsong (Vaal Reefs No. 11 Shaft) and Bunton replacement project at Tau Tona Mine.
4. Case history: Platinum mining: PGM Concentrator.
5. Coal mining: Coating evaluation of overland conveyors V3, V4 and V5 at Douglas Colliery.
6. Bolt & Engineering Distributors – company profile.
7. Made in Africa for Africa – Tel-Screw Products.
8. The difference between zinc electroplated and hot dip galvanized fasteners.
9. Types of fasteners and availability matrix.
10. “Weigh less” for galvanizers – Conrad’s rule.
11. Zinc supplies in South Africa.
12. A breakthrough in zinc passivation.
13. Lula Pipe Systems.
14. Guest writer: Johnny’s Cash’s piece by piece motor car knowledge, by Bob Andrew.
15. Duplex coatings: The  hot  debate  considering  the  effectiveness  of  cathodic  protection provided by either a metallic coating or a zinc rich paint, continues.
16. Coating report: Evaluation of ‘zinc coated’ wire mesh.
17. Coating report: Hot dip galvanizing of light weight mesh reinforcing.
18. Misconceptions: The hot dip galvanizing process has a deleterious effect on the mechanical properties of special steels. True or false?
19. Walter’s Corner: The introduction and history of hot dip galvanizing in the mining industry.

Volume 3, Issue 3: August 2006 (28)

7. 1. 2006 Eskom Hot Dip Galvanizing Awards, featuring overall winner, category winners and submissions.
8. 2. Hot dip galvanizing of centre pivots.
9. 3. Riversmead Poultry Farm.
10. 4. Fairacres Dairy Farm.
11. 5. Karan Beef – a world class enterprise.
12. 6. Hot dip galvanized cable ladders – quality surveillance report.
13. 7. Selection of cable support systems which satisfy both design requirements and optimum life cycle costs.
14. 8. Butterworth Metal Industries, Transkei (Pty) Ltd. – a company profile.
15. 9. Duplex coatings: How economics drive change in managing maintenance costs.
16. 10. Coating report: Hot dip galvanized electrical distribution tubular masts – Tsakane.
17. 11. Personality profile: Derek van Heerden.
18. 12. Misconceptions: Hot dip galvanized structures buried or partially buried in soil, such as cellular masts, electricity pylons and street lighting poles will lead to toxic levels of zinc leaching out and into the surrounding earth over a period of time. True or false?
19. 13. Walter’s Corner: How does hot dip galvanizing perform in immersed conditions?
20. 14. Report on Intergalva 2006.
21. 15. Readers’ comments – How to select zinc silicate primers.
22. 16. Walter Gordon Stewart Barnett: 41 years in the industry.
23. 17. A well-know hot dip galvanizer reluctantly decides to call it a day – Bill Garvie.
24. 18. Guest writer: Like light, people and companies can be different things at the same time, by Bob Andrew.

Volume 3, Issue 2: June 2006 (27)

1. High frequency welding or electric resistance welding of tube and pipe.
2. Automatic hot dip galvanizing plants for tubes and pipes.
3. Testing adhesion on hot dip galvanized pipes.
4. Why vent holes are extremely important when closed tubular components are to be hot dip galvanized.
5. Trucking and Engineering (T&E): a company profile.
6. Pressed steel sectional water tanks.
7. Roundabout Playpumps.
8. Bulk water storage.
9. The primary marketing objective of the HDGASA.
10. Update of MERSETA and skills development.
11. Hot dip galvanizing: the steps required to ensure a good product.
12. From decision by the end user/specifier to use hot dip galvanizing as the preferred corrosion control coating to receipt of the finished components – site and overall experience.
13. Duplex Coatings: Warranties and guaranties.
14. Duplex Coatings: Recycling garnet in the shop and field.
15. Corrosion report: Corrosion of hot dip galvanized piping used for re-circulating mine water.
16. Corrosion report: Hot dip galvanized pump station platforms.
17. Personality profile: Sue Clark.
18. Case history: “Braithwaite” type pressed steel water storage tank.
19. Misconceptions: Hot dip galvanizing of reinforcing steel for concrete only works if you don’t need it. True or false?
20. Walter’s Corner: A good looking coating is not necessarily a good coating.
21. Guest writer: Enhanced brain power can lead to greater will power, by Bob Andrew.

Volume 2, Issue 2: June 2005 (23)

1. Site bolt or site weld, the debate rages on! By Spencer Erling, SAISC
2. Hot dip galvanizing of threaded components.
3. Bolted connections, an in-depth study with tables.
4. Acceptable/rejectable surface conditions relating to centrifuges components.
5. Hot dip galvanized fasteners haveV excellent abrasion resistance.
6. S.A. Bolt Manufacturers: a company profile.
7. CBC Fasteners: a company profile.
8. Avlock International – lockbolt fastening systems: a company profile.
9. Tel-Screw Products (Pty) Ltd: a company profile.
10. Self-drilling screws.
11. Expansion bolts.
12. An evaluation of coated self-drilling screws.
13. New specification covering fasteners for roof and wall cladding.
14. Corrosion in roofing fasteners and seals.
15. Performance of coated self-drilling screws.
16. UPAT S.A. (Pty) Ltd: a company profile.
17. Threaded protection on welded nuts.
18. Impala Bolt @ Nut A. (Pty) Ltd: a company profile
19. National Socket Screws: a company profile.
20. Bascol (Pty) Ltd.: a company profile.
21. WLS Fastener Manufacturing Company cc: a company profile.
22. Standardisation of holding down bolts.
23. Fastener Coating Comparisons – a table.
24. Ideal Bolt: a company profile.
25. Types of Fasteners and Availability Matrix.
26. Hot dip galvanized bolts still “shine” while guard rails discolour and corrode.
27. “Zincalume” versus hot dip galvanizing.
28. Increasing the possibility of achieving a quality hot dip galvanized coating.
29. An evaluation of material and coating for railway sleeper shoulders – Pandrol South Africa.
30. Hot dip galvanized coating repair materials – a comparison in terms of the specification requirements.
31. Defects on thread profiles can affect coating quality.
32. Appropriate corrosion protection.
33. SAISC updates the “Red Book”. By Spencer Erling.
34. The effects of temperature on steel with 0.20% carbon content.
35. Introducing SANS 1431 grade 350WA structural steel.
36. Guest writer: The indigenous knowledge of bushmen has relevance to modern business management and leadership.
37. Personality profiles: Tom Motlhake and John Ngwenya.
38. Case history: Mitchelsplein Train Station/ Transport Interchange.
39. Walter’s Corner: Fighting the common corrosion enemy (Part 2).
40. Misconceptions: Hot dip galvanizing provides both barrier and cathodic protection, which is why small, uncoated steel surfaces are not significant since they will not influence the overall corrosion control life of the coating. True or false?

Volume 2, Issue 1: March 2005 (22)

1. Hot dip galvanizing of sheet metal, including tables of specifications.
2. Lightweight steel construction in the residential market.
3. Corrugated iron has stood the test of time.
4. Hot dip galvanizing of wire: an in-depth study.
5. Meshpack grout support system outperforms timber as stope supports.
6. Protecting bridges with gabion baskets: Rivi-Rivi Bridge, Malawi.
7. New report on performance of zinc coated wires in the South African agricultural industry.
8. 2005 Eskom Hot Dip Galvanizing Awards: criteria and call for submissions.
9. 2004 Awards: prominent projects and category winners.
10. Personality Profile: Al Stratford.
11. Zinc appears to improve childhood hyperactivity disorder.
12. Guest writer: Productivity is man’s sustained effort to improve, not an index to impress investors, by Steve Jobs.
13. Misconceptions: Once rust stains appear on a weathered hot dip galvanized surface you can be sure that the coating has reached the end of its protective life. True or false?
14. Case history: Hot dip galvanized steelwork used to widen the Storms River Bridge in December 1986.
15. Walter’s Corner: Corrosion the common enemy (Part 1)
16. Book review: “HDG Steel Reinforcing in Cone” by Stephen Yeomans.

Volume 1, Issue 2: November 2004 (21)

1. Quality control of a hot dip galvanized coating.
2. Evaluation of a duplex system versus a multiple paint coating system.
3. Case history: Eskom’s Saldanha Blouwater substation.
4. Training: Hot dip galvanizing plant operators.
5. Steel is also environmentally sustainable.
6. Hot dip galvanizing and the environment.
7. Project: Gabion cottage walls at Kwandwe game reserve.
8. Honorary life members: Dave Scott and Professor Denis Twigg.
9. Misconceptions: Hot dip galvanized surfaces are extremely difficult to overcoat with paint whether for aesthetic reasons or for additional protection. True or false?
10. Walter’s Corner: Some thoughts on corrosion and corrosion protection.
11. Managing companies with heart and head, by Bob Andrew.

Volume 1, Issue 1: August 2004 (20)

1. 2004 Eskom Hot Dip Galvanizing Awards, with all the winners and award entries featured.
2. The facts about using hot dip galvanized reinforcement in concrete.
3. Hot dip galvanized poles offer regional opportunities for electrical distribution: a contribution from IZA.
4. Related hot dip galvanizing specifications and the SANS equivalent.
5. Project: Mohale feeder roads and bridge.
6. Project: Eshowe pedestrian bridge.
7. Misconceptions: Specify heavy duty hot  dip galvanizing  or  cadmium electro-plating for superior corrosion protection of fasteners.  The mechanical action of a spanner will damage the coating. True or false?
8. Walter’s Corner: Could we exist without zinc?