Copper welding

[andypocock]

Does anybody here have any experience of tigging up copper plate? I'm interested in it's possibilities for small pressure vessels:

http://www.maxitrak.co.uk/welded boilers.pdf

I've constructed a couple of boilers with silver soldered copper and I'm very good at unsoldering a neighbouring joint just as fast as I make the new one. At least if something is welded it tends to stay that way.

It sounds as if it could be tricky but the guy in the article seems fairly laid back about it.

Cheers All

 

[runnach]

Morning, made ten off model boilers years ago, divorced one a few years ago too

Tigging up took a fair bit of pre-heat & many temple sticks. I did have problems when it came to eg; silver soldering condensor tube, also taper stays around firebox area. Stays were not copper, such a long time ago, I can't remember matl type? But I do recall when our rod rep popped in with some gear, he suggested I use some other type of welding rod for welding differential matls, worked a treat, no more silver solder was used around parts very close to each other, made for face when pressure testing.

Good luck with your project n cheers............

 

[fingers99]

There's some mention of TIGing copper on the Ron Covell video. Seems a lot of heat as it's such a good conductor and the right rods (de-oxygenated) as otherwise you'll have a porous weld (the very last thing you want in a boiler). No reason you shouldn't do a bit of practice with old electric cable though!

Sheer intricacy of those boilers aside, it shouldn't pose any problems.

Let us know how you get on, where you source the rods, etc.

 

[Weldingartisan]

I've tigged up a few modified copper plumbing fittings so that they didn't fall apart when brazing up. Just used clean copper wire for filler and a bit more heat for welding, held up ok on a pressure test. W/A

 

[andypocock]

Thanks chaps. Sounds like after a bit of practice the biggest problem is going to be keeping heat in the thing but if I keep a big propane flame to hand that's not too much of a problem. As the boiler comes together it might be possible to leave a torch playing on the end I'm not welding.

Are we all talking DC here? I wondered about AC for the same reasons that it's used an aluminium.

Andy

 

[Weldingartisan]

I used DC.W/A

 

[fingers99]

DC. See how you get on with Argon. May be (and I'm guessing here) that this is a case where Helium would help.