Powder coating galvanizing steel.

[rogerthebodger]

The stern of my Distantshaws is a hinged steel steps and is starting to rust, I am thinking id getting it grit blasted then galvanized. I wish to have it powder coated white to match the rest of the painted boat.

Any one have any comment on powder coating over galvanized steel.

 

[coopec]

Roger

I presume you've googled?

Can galvanized steel be powder coated?
A. You can powder coat galvanized steel just fine, just make sure you don't get passivated galvanized. There is a little more involved with treating galvanized, but with the right process it can be successfully done. Just remember, Iron Phosphate will not form in the areas where there is no iron.

Uh? Don't ask me to explain what they are getting on about!

My mate used had a powder coating business and I'm sure there were no problems.

 

[Neeves]

Someone will pop and say powder coating is a very general term and that there are many variants. But Geoff runs both galvanising and powder coating plants and should be a good source of info.

I have been using Armorgalv as a process for galvanising. I don't know if there is a processor in SA. Armorgalv is said to produce a coating very amenable to powder coating as it has, anecdotal comments coming up, a porosity at right angles to the original surface. This porosity allows the development of a very strong adhesion of the powder coating on the underlying galvanising.

The owner of the process in Australia specifically used Armorgalv as his main business was road signs, on highways, and he galvanised and then powder coated.

It might be worth checking.

The licence to use Armorgalv is through a company in America called Distekna (I think that is the spelling) and they have (hopefully had) a terrible website - but it did have a list of the various operating plants round the world.

There are competitive processes: Google - Thermal Diffusion Galvanising - and it will throw up other processes 2 or 3 I recall - none of which are in Australia, hence my vagueness.

Armorgalv, and I assume the other 'similar processes' produces a much harder galvanised coating, so more abrasion resistant. Just make sure you focus on coating thickness as it is possible to produce a decent - thin - coating that will resist corrosion but abrasion is a function of coating thickness - the thicker the better (but if you use hot dip galvanising, too thick might flake).

Jonathan