Thread: Dump Pipe

Originally Posted by HotWired

Thankyou everyone for the replies. Got an idea of how im going to do it, and some bits and pieces are on there way. Also going to look at converting my arc welder to tig, and see how it goes.

Originally Posted by steveG

IMO, unless you want a TIG for other stuff I wouldn't bother. By the time you get gas and torch it becomes a resonably expensive exercise, and then you still have to learn to use it if you haven't done TIG before.
Instead, get some 2mm arc rods and use those to tack it up. Depending on your skill level you should be able to do the actual welds with those too. Keep the current down, the runs short and cool the tube off in between runs with a wet rag and you should be fine.
If you're not confident with that, then just tack it and take it to your local exhaust place to weld. Should only cost you a few $$$ and you'll get a decent job.

Steve

For fine work like a dump pipe TIG would be the the way to go.. but you'd have to purge the pipe with argon first. I imagine you would want to do that with Arc as well if you want really good penno (dont want any cracks).

Purging stainless is what I neglected to do whilst making my first set of intercooler tubes and as a result the inside of the tube was not the best as most will know....having said that a mate of mine did do some excellent stick welding 1mm thick stainless sheet but he is also a tool maker by trade and everything needs to be perfect ..
Im interested in what John said about alloy stick welding

Definitely purge intake piping before welding. But for exhaust I don't care. What's a bit of slag on the inside going to do?

Matt you wont be stick welding alloy tho i can do a nice job at home with the tig and purge the inside so it looks as good as the outside

Originally Posted by Dougal

Definitely purge intake piping before welding. But for exhaust I don't care. What's a bit of slag on the inside going to do?

I agree..

Originally Posted by lokka

Matt you wont be stick welding alloy tho i can do a nice job at home with the tig and purge the inside so it looks as good as the outside

Chris did u just dob yourself in then ??? with the purging is there a fitting that goes on the bottle to divert some argon to use elsewhere ? Or is there a second bottle required ? Or do you block off the tube and trap gas in there ?

Originally Posted by c.h.i.e.f

Purging stainless is what I neglected to do whilst making my first set of intercooler tubes and as a result the inside of the tube was not the best as most will know....having said that a mate of mine did do some excellent stick welding 1mm thick stainless sheet but he is also a tool maker by trade and everything needs to be perfect ..
Im interested in what John said about alloy stick welding

I never said anything about stick welding, just replied to an earlier post re. using a stick welder as power supply for tig welding. Aluminium TIG requires AC, steel DC, so the stick welder is ok for aluminium, but needs high frequency superimposed.

Regarding purging, for pipework or other hollow sections where you can only weld from one side, can't access the inside to back gouge and weld or use a backing strip, air causes problems with the weld. As well as purging with inert gas, it is necessary to continually run the gas to stop air infiltrating. This is a big issue with pressure piping and alloy materials, but not so much for an exhaust pipe. For a custom exhaust manifold, where temp and thermal cycling is greater, then I would definitely use it.

Edit: use a bung or rags to block both ends to minimise loss of inert gas and a run the hose in through one end.

Originally Posted by Bush65

I never said anything about stick welding, just replied to an earlier post re. using a stick welder as power supply for tig welding. Aluminium TIG requires AC, steel DC, so the stick welder is ok for aluminium, but needs high frequency superimposed.

Regarding purging, for pipework or other hollow sections where you can only weld from one side, can't access the inside to back gouge and weld or use a backing strip, air causes problems with the weld. As well as purging with inert gas, it is necessary to continually run the gas to stop air infiltrating. This is a big issue with pressure piping and alloy materials, but not so much for an exhaust pipe. For a custom exhaust manifold, where temp and thermal cycling is greater, then I would definitely use it.

Edit: use a bung or rags to block both ends to minimise loss of inert gas and a run the hose in through one end.

Auh I get you now....