Probably Stupid Welding Question

Thanks H. Maybe I'll set fire to it next week when it warms up a bit here.

 

Well that doesn't make any sense. Do it right now, while it's cold as heck, melt some snow with it.

 

I agree with Howard about soldering the joint.

I have fixed a couple of tanks which leaked around the seams by soldering. I used a MAP torch with high silver content soldering wire and a good flux, clamping Vice Grips each side of the leak to act as heat sinks to keep the heat from opening new leaks.

 

I find Muriatic Acid (Tinner's Flux) to help enormously in prepping. Deep cleaning is key to successful sealing.

 

Yes, good cleaning is critical for a good joint, and Muriatic Acid flux works good. I used to build banjos which had two piece suspended brass tone rings, a hoop sitting on top of a scalloped truss. These pieces were under tension which tended to pull the joint apart, so had to be clamped together. Getting a good joint in both the truss and hoop was critical for getting optimal sound out of the instrument.

 

The only reason I used the more expensive silver solder was because that is what I had on hand since I used that for the banjo parts.

 

I've welded on several gas tanks over the years. Some have been sitting for years with no gas in them, some were in use just prior. Either way, I flush them out really well with just regular hose water. I'll fill it up and let it run out for an hour. Drained and dry I sniff for fumes. If it's not heavy I do the stand back and stick a torch in the neck or the hole or wherever to make sure it's not gonna blow from fumes. I've never had one explode after flushing. If the torch doesn't ignite it, it should be good to go in my experience. Last one I did was this past fall to get an auxiliary tank back in my bumpside highboy for the Glacier/Yellowstone trip. The old one was too far gone with rust to repair, and a friend had one that had been sitting awhile but was in relatively decent shape, and far better than mine. Shape was about right, but I had to add some brackets, move the filler neck and plug off some holes. Flushed and torched, then cut and welded.

 

Well, swimming in the ocean has been safe "in my experience." Doesn't mean there aren't any sharks.

 

Sharks don't worry me, they are just hungry fish. It's the mammals that will drag you by the hair and literally play with your dismembered body.