tig welding stack of dimes

[norlander]

Back purging stainless exhaust is not needed, its only done if you want the inside neat and smooth, I only do it if someone asks, never had a cracked exhaust because of lack of purging.

Excellent -if it was essential to back purge stainless it would be an expensive pain for me.
Do you bother to try to clean the inside of the tube before welding??

 

[justmental]

the thing with tig it needs to be clean.
and the fit up needs to be good (no gaps)
take you time and so not to put to much heat in to it

 

[ericoneill]

the thing with tig it needs to be clean.
and the fit up needs to be good (no gaps)
take you time and so not to put to much heat in to it

done a few little runs

 

[langy]

Excellent -if it was essential to back purge stainless it would be an expensive pain for me.
Do you bother to try to clean the inside of the tube before welding??

The stainless tube I use is all brand new so just a wipe with a acetone rag and away we go.
Purging is easy, I have a dual reg fitted with twin flowmeters, one for the machine and the other for purging.

 

[norlander]

The stainless tube I use is all brand new so just a wipe with a acetone rag and away we go.
Purging is easy, I have a dual reg fitted with twin flowmeters, one for the machine and the other for purging.

Cheers 4 that.

 

[SBK]

Heres my best efforts.

 

[Jim Davey]

It looks neat enough and even, but it's either gone in a little too hot or not enough filler added (possibly a touch of both) as you can see a little undercut where the heat has caused the tube to melt into your weld pool a bit too much.
Pulse can help to control runaway heat, or even pulsing the trigger/pedal if you haven't got a pulse function on your set. Either that or chucking some more filler in or moving a bit faster will help to avoid undercut.

 

[kezajones]

Just to add although back purging isnt needed, If your planning on making a turbo manifold i defiantly would as you don't want nasty bits of sugaring getting blown into the turbine! Another option would be Solar Flux Type B but that would require running the engine up with the manifold on before installing the turbo, of course if the manifold is for an N/A application all of this is irrelevant.

Kieran

 

[chevy2]

It looks neat enough and even, but it's either gone in a little too hot or not enough filler added (possibly a touch of both) as you can see a little undercut where the heat has caused the tube to melt into your weld pool a bit too much.
Pulse can help to control runaway heat, or even pulsing the trigger/pedal if you haven't got a pulse function on your set. Either that or chucking some more filler in or moving a bit faster will help to avoid undercut.

As above^^
A combination of a little too much heat and possibly travel speed too slow hence the slight loss off weld definition,
You have the dimes there but just not quite as sharp as i guess you're looking for,
Good effort all the same

 

[SBK]

It was done with pulse,was playing around for the first time.Was using 1mm filler very sparingly,Tube is 1.5mm.Your right about the undercut had amps set to 30 low 55 high,1 pulse per second.Will have another play with it.seems to be a very fine line between getting the base to melt rather than blowing holes.

 

[langy]

It was done with pulse,was playing around for the first time.Was using 1mm filler very sparingly,Tube is 1.5mm.Your right about the undercut had amps set to 30 low 55 high,1 pulse per second.Will have another play with it.seems to be a very fine line between getting the base to melt rather than blowing holes.

I wouldn't use pulse to do that, just normal but not 50 amps