Welding Tips and Tricks

About two years ago I made smoker for my father in law using two drums welded together like a "T"
Now, I'm being asked to make one out of stainless drums. I think it will be a fun project, but I'm not sure how best to purge the back sides of both drums... it is a complex, curved, surface so I can't really think of a way to put a backing bar. I was hoping to avoid filling the entire drums with argon because it will take a lot of gas.

PS... I'm a chemical engineer by training who does some welding as projects arise... I'm no where near the experience that most of you probably have.

I'll take whatever tips you are willing to give!

Welcome to the forum! Be aware that SS does some crazy things when heated so you are liable to get some serious distortion when the grill gets hot. I wouldn't bother purging metal for a grill but sugaring will shorten the life of your product so I would recommend a product called Solar Flux B. You mix the powder with alcohol and put it on the back side of your weld and it blocks air from reaching the weld and prevents sugaring. Should work perfect for a grill.

Firstly, welcome.

Secondly...have you considered using something like Solar B flux on the back side? I've tried it and seen good results, there are others on here who have used it and been happy with the result, too. It leaves a hard glassy residue on the back side that looks like pottery glaze.

EDIT - oops, I see Exnail beat me to it!




Kym

Welcome aboard!

I can suggest two options off the top of my head. One is to use 3-4" wide strips of aluminum foil tented and taped to the back side of short sections as you weld to localize your backpurge and minimize consumption. The other is to simply use 100% nitrogen and purge the whole thing. N2 is about 10% the cost of argon if you can borrow a bottle or are on good terms with your welding supply and can skip the lease for a short-term use.

I use some variation of the former for code welds, and almost always the latter for non-code work. (The N2 would work for the code work, but the WPS specifies argon.)

I have also heard, anecdotally, that CO2 will give an acceptable finish if you control your heat, despite being an active gas, for this kind of application, but I'd wait to hear from someone with actual experience before considering it.

Regardless, you're going to want to minimize heat input and move around a lot, as thinner stainless is going to be subject to much more distortion than the mild steel barrels.

I'd love to hear how this project goes for you.

Steve S

Yeah,

I've only done one stainless steel exhaust system, but my instant impression is that back-purging is unnecessary for a grill project.

Solar Flux may be more than an adequate and convenient solution as an extra measure, though.

As some suggested you can use thin metal and bend to create a tented area behind the weld, hold it in place with heat tape and introduce a argon purge.

Welding thin stainless without a purge is going to be more difficult.

Note the thin copper sheet circled in red, you don't have to use copper, aluminum foil will work but I'd double up and don't let it too close to the back side of the weld.

Perhaps a test weld with your purge setup would be prudent before trying the real deal.

If you won't see the other side of the weld and its not used in contact with the food or anything else, I wouldn't be worried about it, just weld it without any backing or purging, if your worried about burning through too fast or hard, you can back it, but I wouldn't worry about shielding the backside.

Wow. This is awesome feedback. Thanks for responding so quickly.

I just did some studying up on Solar Flux B... I want to try some... I have already thought of a few projects including this one.

I'm planning on using pulse to try and minimize distortion, but I haven't determined the settings yet.

I will get some Solar Flux B and some used drums to play with. Thanks again.

Sent from my Nexus 5X using Tapatalk

rjd1234 wrote:Wow. This is awesome feedback. Thanks for responding so quickly.

I just did some studying up on Solar Flux B... I want to try some... I have already thought of a few projects including this one.

I'm planning on using pulse to try and minimize distortion, but I haven't determined the settings yet.

I will get some Solar Flux B and some used drums to play with. Thanks again.

Sent from my Nexus 5X using Tapatalk

Are the drums sheet metal? Like 22 or 24 gauge? how thick is it?

One factor to consider, it can warp in so many ways if its thin sheet, ways you won't even imagine