Rust Repairs: Welding In Stainless Sheet

[Sam_Q]

It looks like I need to do some serious rust repairs to my wagon and I was thinking I have a large pile of 2mm thick stainless steel sheet. I would like to know can I get away with welding this in to replace any rusted panels I take out? I would rough it up with a flapper wheel so everything can stick to it.

[eiriksmil]

I don't remember right now if it's just alu or also ss that you can't weld up with regular steel. Also, 2mm might be too thick for some places, replace the steel with the factory thickness. Think steel is good but you need more heat to weld the thicker steel, so you risk burning holes if the rest of the steel is thinner.

 

You live in Australia? And your car is rusty? Let's see it :D

Edited December 1, 2009 by eiriksmil

[67Rolla-Ken]

Here's some Australian rust for ya

Stolen from the rusty relics thread.

[Sam_Q]

I don't remember right now if it's just alu or also ss that you can't weld up with regular steel. Also, 2mm might be too thick for some places, replace the steel with the factory thickness. Think steel is good but you need more heat to weld the thicker steel, so you risk burning holes if the rest of the steel is thinner.

 

You live in Australia? And your car is rusty? Let's see it :D

 

well my whole exhaust was made with stainless tube with mild steel wire. Just about every other exhaust in the country is the same. Why would 2m be too thick? extra weight or just the buring issue you mention? I think I am pretty good at welding thin sheet so if thats it I will still give it a go.

 

Yes lots of bubbles, spots and a few holes but not whole pieces missing, have mercy our rust just doesn't compare! hahahaha

[philbey]

Yes - you can weld stainless to mild steel, no problems. Thickness difference shouldn't be an issue for a competent welder.

 

BUT - there's a very good reason why you wouldn't do it - you'll probably get worse corrosion issues. You're creating a perfect setup for Galvanic corrosion and in the presence of moisture you'll most likely accelerate any corrosion issues, moreso than if you have mild steel. You'll also have a harder time painting the stainless.

 

Don't waste your time.

 

Oh you can get away with it on exhausts because they run hot and moisture isn't an issue - same reason you can make exhausts out of mild steel.

Edited December 1, 2009 by philbey

[altezzaclub]

I'm afraid Mr Philbey is right, and the exhausts are a particularly crap stainless really. I think you would have a lot more trouble cutting & shaping 2mm stainless, plus welding two different thicknesses, so it would be easier all round to get half a sheet of 20guage mild.

 

Still, it would be interesting for the rest of us to find out what problems stainless does bring... give it go Sam!

 

:D

[philbey]

Not a bad article on it here

 

http://www.corrosionist.com/Galvanic_Corrosion.htm

[Sam_Q]

ok thanks back to plan A, using the washing machine steel, apparently they are the best for this sort of thing.

[Sam_Q]

hey thanks for the link philbey, that really explains it well. Theoretically though the area affect should come into it and it should be fairly safe.

 

altezzaclub: Hey!! yeah maybe but not on my car, hahaha

 

gee good thing I didn't fit those Sodium bolts eh

[67Rolla-Ken]

Oh and happy birthday Sam :D

[Sam_Q]

thanks but my B/day is in September, I lied!

[styler]

haha bloody good idea in theory! but philbey is right about it being a problem, basically with any two metals together

the more reactive one corrodes hence why you get corrosion at the meeting point of the two and why they will pair a

lot of reactive metal with another small amount of sacrificial metal that is more susceptible to corrosion in its enviroment,

eg mild steel parts having a more reactive zinc plating or mild steel is hot dipped galvanized in the more reactive zinc, and

boats have a zinc sacrificial anode so it corrodes instead of the hull and can be replaced as needed.

Edited December 1, 2009 by styler

[philbey]

There's a reason Thermostat housings are made of shitty cast zinc alloy - it chews out before your aluminium head and iron block do.

[KESR20]

You can weld stainless steal too metal n vice versa, its when u try aluminium too other metals. stainless is just metal in a altered state so ofcourse it can be welded! i love looking at stuff welded like that, because after a few months of oxidization you see whats what hahaha

[styler]

You can weld stainless steal too metal n vice versa, its when u try aluminium too other metals. stainless is just metal in a altered state so ofcourse it can be welded! i love looking at stuff welded like that, because after a few months of oxidization you see whats what hahaha

 

"you can weld stainless steel to some other types of steel with varying rates of success. you can't weld aluminium to steel very well. stainless is the type of steel alloy with active part chromium added so can be welded to other steel alloys with varying rates of success. i like looking at the oxidation of the more reactive steel and the less reactive steel that occurs when exposed to a corrosive environment."

Edited December 15, 2009 by styler