Spray painting galvanized

[jmarkwolf]

I need to paint some corrugated steel roofing panels flat black in order to absorb welding flash in a welding booth I'm constructing.

Anyone on the forum have a simple procedure with commonly available materials (primers, etchants, paints, etc)?

Doesn't need to be prize winning quality. Just want it to hold up and not flake off.

 

[e30bradley]

If you want to do a quick job just scrub it with TSP and red scotchbrite, then rinse and scrub with dish soap, then spray an etch primer, then topcoat.

If you don't want to use a spray gun you can brush latex primer on galvanized steel. I have had good results with this. Oil based paints (and primers) react with the zinc coating and will peel or fail in one way or another in a short period of time.

 

[fnieto]

I've had good luck using viniger to clean galvinized prior to painting.

 

[LS6 Tommy]

Why go nuts mixing stuff? There are primers for galvy. Kilz 2 works well. Never tried the Krylon galvy primer. Either way, water based is what you want. Oil based primers and paints react with the zinc in the galvy and will peel off after a while.

Tommy

 

[Boomer343]

Why are you worried about flash? Shops weld galvanized materials without special precautions for flash all the time. If you want to paint it do it in an easy to clean product other than flat paint.

 

[Zeke]

Why are you worried about flash? Shops weld galvanized materials without special precautions for flash all the time. If you want to paint it do it in an easy to clean product other than flat paint.

I think he said he wanted to black out his booth. Nothing like welding in a house of mirrors.

OP, clean the metal any way and then apply phosphoric acid. Rinse and dry. You should see the galvy now attacked and ready for primer/paint. There are a lot of direct-to-metal paints. Since most primers are white, no need to go backwards and have to paint black over white. Just get a DTM flat black.

 

[jmarkwolf]

Why are you worried about flash? Shops weld galvanized materials without special precautions for flash all the time. If you want to paint it do it in an easy to clean product other than flat paint.

Just being an overcautious newbie. Painting is easy, flash burned eyes are not.

I've read accounts of welders getting flash burn just from wearing white clothing.

Mirrors are for the bedroom, not the welding booth!

 

[LS6 Tommy]

While we're on the subject of welding safety, don't forget welding/burning galvy requires proper ventilation or a respirator to avoid "fume fever".

Tommy

 

[Kevin54]

Here is a PDF on prepping galvanized for painting. http://www.galvanizeit.org/images/uploads/articles/paintprep.pdf

Most of the time though, unless you want to go into an involved process, Scotch-Brite the surface, then wipe it down with household vinegar. Use white vinegar. Then prime with a decent primer, then paint.

And as LS6 stated......if you burn or weld the galvanized to put panel together, make sure you have very adequate ventilation. Very important!!!!

 

[jmarkwolf]

Thanks for the input everybody.

Won't be welding any galvanized, but I am aware of the hazard of doing so.