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Stainless steel panels to mild steel chassis?
Slimy38 - 9/2/14 at 12:19 PM

A very quick question, there is a sheet of stainless on Ebay at the moment that may end up quite cheap. Is it possible to weld stainless to mild, assuming mild steel wire and argoshield gas?

loggyboy - 9/2/14 at 12:25 PM

I welded up a stainless exhaust a few yrs back with mild wire and had no issue. Wasn't joining mild steel though, just adjusted the pipe angles.

snapper - 9/2/14 at 12:30 PM

You can weld with mild filler but welds will be mild and rust
May be brittle so as long as it's not the floor should be fine
If floor I would bond and put a couple of bolts in

Jon Ison - 9/2/14 at 12:43 PM

Just a word of caution, on my original build I used stainless panels all round, looked good, however I have since ditched them, very heavy in comparison to other materials available.

Slimy38 - 9/2/14 at 12:46 PM

quote:
Originally posted by snapper
You can weld with mild filler but welds will be mild and rust
May be brittle so as long as it's not the floor should be fine
If floor I would bond and put a couple of bolts in


Part of it was going to be the floor, brittle doesn't sound good. Not worried about the rust as I'd have to protect the chassis and panels anyway (if I stick with mild steel instead).

Edit: Mmm, perhaps bond for floor and weld everywhere else?

[Edited on 9/2/14 by Slimy38]

Slimy38 - 9/2/14 at 12:47 PM

quote:
Originally posted by Jon Ison
Just a word of caution, on my original build I used stainless panels all round, looked good, however I have since ditched them, very heavy in comparison to other materials available.


Very heavy? Did you go for a thicker panel then? The sheet is 1mm which I thought is ok for steel (too thin for aluminium).

sa-fabrication - 11/2/14 at 09:55 PM

Stainless is heavier than mild steel.

Ally is atleast half the weight of Steel.

Problem with stainless is it can friction weld to steel. for example if you have a stainless bolt and a mild nut, the heat generated by doing the nut up can friction weld itself together. Ive had this a few times.


Just a personal thought. If the chassis is mild steel why do you want Stainless? if its for the floor / trans tunnel then use ally. I can pick a 8'x4' sheet in 1.5mm up for £60 or 1.2 for £40 (remember ally is sold by weight)

Fred W B - 12/2/14 at 06:33 AM

If we are going to give advice let’s get it right.

If you want to weld stainless to carbon, it can be done successfully you just have to use the right grade of consumable. Stainless is alloyed to give certain properties, if you dilute the alloys you end up with the wrong structure and form a brittle rather than a ductile weld.

When welding to carbon steel with 316 use 316 electrodes, when welding with 304 use 309 (best) or 316 electrodes.

As others have said you may "get away" with welding with a carbon steel consumable but don't trust it in a stressed application.

As for the mass of the different materials it varies with the grades, but for general purposes you can used densities as below

Carbon steel 7830 kg/M3

Stainless steel 8070 kg/M3 (so only slightly heavier than carbon steel)

Aluminium 2730 kg/M3

Cheers

Fred W B


[Edited on 12/2/14 by Fred W B]

Slimy38 - 12/2/14 at 09:34 AM

The only reason for the stainless was that it was a cheap auction, but as it happens it went quite high anyway so I didn't go for it.

My entire build is sticking with the locost idea. I have more time than money, so I'm willing to wait for the random Ebay auctions to pop up and get a bargain.

I think by the sounds of it I'd do better just watching for normal steel or aluminium. Thanks for the replies.

mcerd1 - 12/2/14 at 11:28 AM

have a look at this for a very locost floor

steel floor 2
steel floor 2

http://www.locostbuilders.co.uk/viewthread.php?tid=100672