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Health and Safety question regarding welding and zinc primer

Posted: Sat Nov 22, 2008 11:59 am
by Dean
Hi all,

My next job is to weld up a few small holes at the front of my chassis leg. I was considering getting some Weld-Thru zinc primer from frosts and spray this to my steel before welding to protect the bare steel inside the leg and any overlap.

I was told though that zinc primer during welding gives off a poisonous gas, so was told not to do this. Is this right? If this is the case how do I protect the new steel inside the chassis leg as I can't get to it afterwards?

This is the product by the way, it does suggest spray component prior to welding??
http://www.frost.co.uk/item_Detail.asp? ... ostSubcat=

Posted: Sat Nov 22, 2008 12:06 pm
by jonathon
It is true, so wear a toxic mask. Its also true for all welding, the gasses are toxic. :( :o

Posted: Sat Nov 22, 2008 12:15 pm
by Dean
Toxic mask it is then... thanks Jonathon. :)

Posted: Sat Nov 22, 2008 12:18 pm
by aupickup
you can not be to careful

Posted: Sat Nov 22, 2008 1:36 pm
by rayofleamington
Zinc plated steel is probably worse than the zinc spray - not to mention the nasty fumes that come from other things when you're welding.
So make sure you have some ventilation where you are working and try not to keep your head where the fumes rise - this one I often forget!

Posted: Sat Nov 22, 2008 2:34 pm
by bmcecosse
Yes - you can get 'zinc flu' if you breathe in zinc fumes from any metal working. A simple 'dust' mask won't do it - you need a full mouth/nose fitted mask with a carbon filter element - or better still - air fed mask from an external air supply.

Posted: Sat Nov 22, 2008 4:50 pm
by paulk
Galva Flu is 'orrible. Had it once a few years back, not nice at all.

Posted: Thu Nov 27, 2008 10:11 pm
by youngun
Definately wear a mask, zinc poisoning is awful. treat the fumes like 2k paint fumes!

Posted: Thu Nov 27, 2008 10:37 pm
by rayofleamington
Definately wear a mask, zinc poisoning is awful. treat the fumes like 2k paint fumes!
I'm amazed I've never had it so far - as it never really worried me too much despite knowing it's not good (the yellow dust from welding through zinc makes a good reminder that it might be a bit unsafe). After welding near underseal many times I've had to cough out a lot of soot afterwards....

As for zinc weld-thru primer - I hope it does what it says on the tin as I've sprayed a fair bit onto Minors I've welded over the years!
It certainly can't be as bad as leaving the metal bare on a seam - bare seams can rot through in a handfull of years.

Posted: Fri Nov 28, 2008 12:05 am
by alainmoran
rayofleamington wrote: bare seams can rot through in a handfull of years.
Aye, I keep eyeing up a patch I put on one of my chassis legs a few years back ... at the time I only even intended it as a temporary job, and it was my first piece of welding ... I bet I didnt cut enough of the old stuff out, and its probably a good time to whip it off an do it properly since I have the suspension removed already for painting the entire underside in galvanising paint.