welding different metals

BBQ Dreamer · Posted: Sat Aug 21 10 8:20 am Post subject: welding different metals

Can you weld regular steel and stainless steel together? Any concerns about eventual corrosion? I've found a 50 gallon stainless steel diesel fuel tank off of a refrigerated trailer. I'm looking for a tank to use as a firebox and have found 2 of these. Don't these tanks have baffles inside them? What about the diesel smell. Will burning it off get rid of the smell?
Eventually I'll get all the parts together and I'll actually be able to start.

k.a.m. · Posted: Sat Aug 21 10 8:27 am Post subject:

BBQ Dreamer, are you sure the tanks are stainless and not polished aluminum? I have been around a lot of diesel tanks and they are usually aluminum and a 50 gall. tank should not have a baffle in it.
As for your welding question, yes stainless and regular steel can be joined but the weld joint will be contaminated and will rust.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

BBQ Dreamer · Posted: Sat Aug 21 10 8:38 am Post subject:

k.a.m, I thought they looked like aluminum but the guy who had them siad that they were stainless. He had so much other junk, excuse me ..stuff. He probably didn't really know. I'll keep looking. I thought there would be some kind of reaction between the dissimilar metals.
By the way if I didn't say it thanks for the reply to my pm of a few days ago. That's why I'm still looking for a firebox tank. I'd rather it be a little large than to small.

k.a.m. · Posted: Sat Aug 21 10 10:06 am Post subject:

BBQ Dreamer, you are welcome and I am glad I could help. Smile

_________________
Always remember slow and steady wins the race.

Hybrid Cooker

BBQMAN · Posted: Sat Aug 21 10 8:21 pm Post subject:

As KAM said, yes it can be done, and yes the weld will rust.

You are better off bolting something like that together.

I'm a stainless guy myself, and prefer to start with fresh metal.

Stainless also moves quite a bit when subjected to high heat- My firebox is heavily reinforced.

Good luck with your project!
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

12TH AV SMOKERS · Posted: Sat Aug 21 10 9:53 pm Post subject:

k.a.m. and BBQMAN are right but there's no reason not to use it just because it's stainless. The contamination you'll get from welding carbon to stainless is nothing you need to worry about. Yes, the weld can rust but carbon steel rusts anyways so what's difference? As far as stainless steel moving when subjected to high heat, yes it'll move but it's not like it'll move that far.
For the purpose you want it for, if the price is right, and its the size you want, I'd have no problem using it.

Remember though...you can't use a torch to cut stainless. You'll need a plasma cutter or cutting wheels.

peace
_________________
FATTIE THROWDOWN CHAMP
(2) WBS- Wine Barrel Smokers
(2) BDS - Brick Drum Smokers
(1) UDS - Ugly Drum smoker
SMS - Vertical - wood / gasser

http://www.youngbergindustries.com/

BBQMAN · Posted: Sat Aug 21 10 10:38 pm Post subject:

BBQ Dreamer · Posted: Sat Aug 21 10 11:49 pm Post subject:

Thanks guys. I'm not in a rush so I'm going to keep looking. There is bound to be a 40-50 gallon carbon steel (learned something new today) tank out there somewhere with my name on it. The design phase was completed when I saw "farmer fox's" build. Love it. I plan a few modifications of the original design but the end product will definitely be recognizable as his. I'm in the parts collecting phase right now. I have 2- 80 gallon air compressor tanks but I really don't want to cut one up for a firebox. We'll see.
The hunt continues.

12TH AV SMOKERS · Posted: Sun Aug 22 10 1:37 am Post subject:

BBQMAN...I agreed with you 100% on flat ga steel.
St Stl or carbon. I was assuming the tanks were cylindrical in shape. I've seen 3/8" - 1/2 flat steel warp under "firebox" temps. On industrial heat treating furnaces. Thats why the best ones are cylindrical or have major reinforcements.

peace
_________________
FATTIE THROWDOWN CHAMP
(2) WBS- Wine Barrel Smokers
(2) BDS - Brick Drum Smokers
(1) UDS - Ugly Drum smoker
SMS - Vertical - wood / gasser

http://www.youngbergindustries.com/

seattlepitboss · Posted: Mon Aug 23 10 12:44 am Post subject:

Stainless moves more than mild steel during welding or heating. Quite a bit more, actually.

Depending on the electrode metal, the weld metal may rust, or it may not. I got a box of 3/32" electrodes which are useful for welding dissimilar metals. I used those for welding replacement teeth onto a backhoe. The backhoe came back for a different repair, and the bucket and teeth were slightly rusted as usual, but the weld metal was shiny.

An interesting way to join stainless is to MIG braze it using silicon bronze wire (or perhaps phosphor bronze wire, if you can afford it). I've seen it done and it worked great. Much less warping than welding. Can use C25 or plain argon for shielding gas.

I don't know how to definitively tell nonmagnetic stainless from aluminum. I generally tell by weight (density) or appearance. You'll know soon enough once you try to cut or weld it, though!

seattlepitboss