Galvanized metal welding

"Ted" wrote: (clip) I would think the zinc in the tubing would transfer to the welded joint. (clip) ^^^^^^^^^^^^^^ No, it burns off and gives you heartburn. Treat the weld area like bare steel--prime and paint.

There is a spray on cold galv that you can pick up at almost any welding supply store, both shiny and dull finish. It's about $2 & something per can. Just wire brush your welds clean, and spray on the cold galv. It works fine.

Thanks, Jim Jigsaw Custom Fab

You can buy the spray cold galvanising or it comes in brush on paint form. Galvacon and Zinga are some other trade names. I have seen it protecting weld areas for ten years without any corrosion. Regular paint does not stick to galvanising unless you do special preparation in the form of etchants. Randy

Thanks, Jim Jigsaw Custom Fab

Using silicon bronze to braze galvanized will result in much less galvanizing being burnt off. And the bronze won't rust.

Dan

I use this:

No, the zinc transfers straight to your nostrils. If you plan on having a long career in welding, DO NOT BREATHE THE FUMES.

grind area to be welded. weld. then get some self-etching spary can primer from Shewrwin Williams. let that dry for about 40 minutes, then hit ot with cold-galvanizing primer (from home depot). let that dry for about 1 hour, then hit that with some spray can appliance epoxy. this will give you one tough coating to keep the rust away for years to come.

Zinc coating needs to be removed before welding. It will contaminate the weld. Worse, the zinc fumes released during welding are toxic. You can get very ill from inhaling zinc fumes while welding.

To protect a completed weld, you could have the part hot dip galvanized, but the part has to be portable for that. Most galvanizing vendors charge by weight for the service, so it may be reasonable. Another choice for portable parts would be powder coating.

If it's not portable, such as a fence, spray epoxy primer and catalyzed auto pa> Anyone know of a way to make the welds in galvanized fence tubing rustproof?

Right! In our shop we have a $300,000 air scrubber that meets OSHA standards but, for welding galvanized stuff that generates seriously dangerous fumes, we use a tiny $300 selfcontained workstation that we roll outdoors and follow operating procedures described by the poster above.

This is our outdoors workstation:

I got the lincoln ac-225c welder too.

Had the bigger tombstone lincoln, got tired of moving that heavy thing around. Sold it...

xman

Thanks for the great info all. In regards to the dangers of welding galvanized metals . . . the advice is EXTREMELY valid as I have found out the hard way. Several years ago I wanted to do something about the sagging floors in an old house. I looked at the commercial jack posts on the market and decided to save a few bucks and make some from galvanized metal fence posts. Once I got them situated and I cranked the nuts to raise the bolts against the beam I noticed the bolt was turning with the nut. So I decided to weld the bolt head to the metal top plate that I had screwed to the beam. I also decided to weld the washers that the nut sat upon on top of the post so they wouldn't shift under the torque pressure. I figured it wouldn't take long and I could hold my breath long enough to do the job. WRONG!! Before long my head was in a white cloud and I needed air. So I thought, "O.K. Just a few tiny breaths". A few days later I went to the appointment I'd made at the VA because my sinuses and brain didn't seem right. They sent me to get X-Rays. The tech there accused me of moving during the first two X-Rays, so he had someone watch me through a window. When he came back in he said, "I guess that's just the way they are". It's called 'Metal Fumes Poisoning'. It's similar to lead poisoning in that it makes one feel like their brain is nothing but a rock in their head. A better word to describe the feeling is 'Dumb'. Absolutely, unable-to-think-beyond-the-simplest-thoughts, dumb. Luckily though, I think I've recovered.

"Speechless" wrote in message news: snipped-for-privacy@news.sasktel.net...

It is best to remove the zinc before welding and then use a good, high zinc coating after. I use ZRC and it works pretty nearly as well as hot dip.

If parts are cadmium plated then you MUST remove the cad plate before welding or better yet, don't weld them. You know, steel parts with that nice gold-ish color.

Zinc fumes make you very sick but cadmium fumes will make you really sick and KILL YOU.

There are some really nice welding hats with shrouds and filtered forced air feeds to make you safer and more comfortable but they get really pricey in a hurry.

michael