Welding galvanised steel

[duncans]

Hydrochloric acid is sold as drain /brick cleaner, generally called Muriatic acid. It produces Hydrogen which, as you say, is flammabl. If you use it,use it in a well ventilated area.

hydrochloric acid is brilliant for getting galvanized off as a long time ago I used to use it for getting all the galvanized off watering cans to polish them up the Americans loved them at that time you just need to be careful not to get it on your skin I wore a jumper rolled up and I must have got a bit of acid on my arm which I had no idea as it doesn't burn you don't feel it and its made a long scar which is still present to this day

 

[outofthefire]

hydrochloric acid is brilliant for getting galvanized off as a long time ago I used to use it for getting all the galvanized off watering cans to polish them up the Americans loved them at that time you just need to be careful not to get it on your skin I wore a jumper rolled up and I must have got a bit of acid on my arm which I had no idea as it doesn't burn you don't feel it and its made a long scar which is still present to this day

The gas it gives off in the process is very flammable so do it outside or a well ventilated space.

 

[duncans]

if I'm thinking rite always use gloves as I'm sure it goes through your skin it something like that as I was always careful as I can be but obviously I wasn't as I got it on my jumper then I pushed sleeve up as it was a warm day I also used to use lay bare that was used using a current and that took crome off taps to get to the brass then polish them up

 

[zeppelin builder]

im sure we even used it neat as a flux to solder stainless steel with a dirty great hatchet bolt

too dangerous for most people without adequate supervision and training is my take on it
i

 

[Prajna]

Sorry to revive an old thread but I have a few questions about welding galv: What strength HCl do you need to remove galv? Someone in another thread suggested you can weld galv unprepped with 312, obviously not breathing the fumes, and they said it damages the galv less. Does anyone have any further info on that?

 

[fixerupper]

Galvanised steel gets used a lot around here in Crete. All the light box at my local steel stock holder is galvanised no one removes the galv before welding ....

 

[AndVal]

Aren't stainless steel and zinc incompatible? I remember I've read somewhere that this can result in cracking.
Is 312 so rich in nickel that it can weld galvanized steel without problems?

Personally, I would never stick weld with stainless steel rods because they create fumes that are far more dangerous than galvanized steel.

 

[Prajna]

Oh but they run so smoothly and produce the prettiest welds. I can't remember the thread but someone suggested they were great for galv. That's why I was after more info. Yeah, hexavalent chromium isn't the best stuff to breathe, more dangerous than zinc oxide, sure, but all welding fumes are best avoided. I'll be working outside.

 

[desmo11225]

Hello all , having been a welding lecturer a long time ago and having spent the first 10 years of my life working in a coal mine , retired now 30 years , I would say , avoid welding galvanised plate all together and any other coating that has been put on the steel before welding as well.
I was told when young that nearly all material had 3 phases solid [ice] liquid [water] and gas [ steam] zinc has a very low melting point and the "white stuff" is gaseous zinc , if this gets on your lungs it will never ,ever go away this goes for oil , paint , or any thing else you can think of.
My father passed away with coal dust and rock dust ,after spending half his life struggling to breathe , so I was aware of my lungs from an early age , some miners had their lungs removed after a postmortem and you could not smash them with a sledge hammer.
Now all this seams to very frightening , that's not what it's for but please put your health first above the cost of any job your doing , the big question is, "Is it worth it" Look after your selves every one. desmo11225

 

[Prajna]

I'm sure you're right @desmo but galv box section is a very common construction material and I have a stack of it to stick together one way or another. I will be careful, of course, but needs must. Fortunately, I am not in a great rush to get this construction up, so have time to research the best way of going about it. As I mentioned above, the hexavalent chromium that is released when stainless is heated to high temperatures is probably even more dangerous. Either way I'd rather not breathe any fumes.