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Welding galvanised steel to mild
andyd - 4/10/05 at 06:03 PM

Does anyone see any problems with doing this? I'm fabricating a punch bag bracket and have bought a hook which is galvanised. I've read some info that welding this isn't really a problem but will smoke more due to the zinc coating being vaporised.

Just wondering if anyone has any tips that may help me.

It's MIG welding by the way.

[Edited on 4/10/2005 by andyd]

theconrodkid - 4/10/05 at 06:24 PM

the fumes are really nasty and let air pockets in the weld,it wont be very strong,better to grind the galv off first

Marlon - 4/10/05 at 06:26 PM

There is no problem in doing this BUT if you can grind/sand the surface of the galv off where you are welding it will result in a neater and easier weld with les spatter.

miserableoldgit - 4/10/05 at 06:43 PM

Welding problems aside; fumes from galvanising are VERY BAD for your heart lungs.

How long can you hold your breath for?

JonBowden - 4/10/05 at 07:39 PM

I believe Vauxhaull use MIG brazing to overcome the problem of fumes with galvanised replacement panels when repairing their cars

gazza285 - 4/10/05 at 07:45 PM

quote:
Originally posted by miserableoldgit
fumes from galvanising are VERY BAD for your heart lungs.




Makes cigs taste funny as well.

907 - 4/10/05 at 07:57 PM

Hi Andy

Sand / grind off the galv (zinc) about 20mm past the weld area.
Do it outdoors so you don't breath in the zinc dust.

Weld as normal but open the shed / garage door to get some ventilation.

Weld from the side rather than have your head over the top of the weld.

Walk away and leave to cool down.

HTH


Paul G

Peteff - 4/10/05 at 08:30 PM

The amount of fumes you will create with the little bit of welding you are doing there will be negligible, but if you grind the bit off where you are welding they will be non-existant. Don't get paranoid about it.

NS Dev - 4/10/05 at 10:26 PM

on that note, reminds me of a vaguely funny story. We were welding some very substantial hinges to some extremely substantial tubular steel heavily galvanised gateposts for a machinery breakers yard.

We gropund the (really thick) galv back and set too welding. The tube was around 9" dia and 3/8" thick so heavy stuff. After around 5-10 mins welding we became aware of a dense fog around us!

Looking around revealed that the top of the gatepost had turned into a VERY pretty bright green firework, where all the molten zinc on the inside had run to the bottom of the post and eventually caught fire!!!!

andyd - 5/10/05 at 03:27 PM

Thanks guys for the advice. I'll grind the zinc off first and give it a bash.

indykid - 5/10/05 at 09:50 PM

out of interest, will a 3M respirator mask stop the fumes? it stops the smell of grp resin, and also bottom burps incidentally.

i can't say i ever have the necessity to weld a lot of galvanised stuff, but don't fancy zinc fume fever.

cheers for any response
tom