so as i continue practicing my Tig welding skills, i moved to trying to butt two pipes together and weld them together as if i was making an exhaust. Can someone give me a couple quick pointers as to how i should do this properly? all i ded was cut the pipes in half and clean them, and try and weld them back together.

should i make a puddle then drag it to the edge of the pipe? and hope it melts the other pipe as well? everytime i try, i keep just blowing through the pipe, or i cant get the two pipes to melt together

im using about 45 amps on my diversion 165. the pipe is typical exhaust thickness.. maybe 16 guage stainless?

 

Keep bouncing back and fourth heating both sides evenly they should melt together. You can also try heating in a circular pattern to melt the tubes together. You should really add some filler to give it a little more strength.

 

thanks for the advice ill try that tonight. ive been trying to use filler but im still new at this so its pretty challanging haha.

 

Are you backpurging? what size filler? I'd set it at 60 amps and use the petal. I'd also try to perfect fillet welds and butt joints before jumping into pipe and tubing. SS has a small margin of error for how much heat you can pump into it so that combined with trying to learn TIG on tubing is just going to get you irritated.

just IMO.

 

If you are butting the pipes together, then you should be able to do a "hammer" tack. If the pipe is touching, aim right on the seam and just stomp the pedal quick...on then off. Do it quick and it'll tack it together.

Aside from that, if there is a tiny gap of any kind, the hammer tack method won't work. With a slight seperation you have to use better heat control because the heat is going to be directed to one side. Sometimes a good way is to sit the filler in the spot you intend to tack and kind of start your arc on the end of the filler. You can once again do a hammer tack that way.

I understand you are trying to weld the pipe and not tack, but most mock up requires you to tack it in place first. Plus you want to tack around a pipe several times, so that when you begin welding one side it doesn't pull the other side opened. With that said, do your tacks, then begin your weld from one of the tacks.

You just gotta really watch the puddle form and be careful with your heat control. Once you weld from one of the tacks though, its pretty easy, but if there's any gap your gonna have to push that filler in quicker to keep from blowing out and be ready to respond by reducin the amps a bit. Practice....

 

thanks alot RC000E that info really helped, im gonna try the Hammer tack method tonight.

im not backpurging at all by the way.

 

This is so strange because I am in the exact spot as the OP. I even have a Diversion 165 and have been struggling to tack ss together. Let me just say, I felt like such a failure that I couldn't even tack two pieces of metal together. Wow. As RC000E was talking about, I somehow learned the "hammer" tack and have been using it. And yeah, there certainly can be no gap.

I do have this question to add on to the thread because I am in the same boat as the OP: I am mocking up my downpipe so I can then ship it out be be professionally welded. With many of my pie cuts I am seeing gaps when fitted against the other pieces of up to 2mm though I am using a belt sander to get a flat side. Will these gaps prevent the piece from being welded up?

 

They will not help. For pie cuts I ues a chop saw to ensure a straight cut.

 

I am using a chopsaw to cut, belt sander to debur the outside edge, and files to debur the inside, then belt sander again.

Can the ss be welded with a gap 2mm gap in some places? I believe it is 16g.

 

It can, but no chance as a beginner. Why make it harder for yourself?

2mm is a bigger gap than the thickness of your pipe, so you won't want to use a 2.4mm filler rod your going to struggle with a 1.2 or 1.6 to get enough filler in. Make your job easier and make the fitup perfect.

 

Practice makes perfect! Keep at it and you will get it!

 

It might be your chop saw. This is what I did with my chop saw and a round file.


I cut very quickly and gently deburred when I was finished. they touch 360*.

 

How many degrees are your pie cuts? I'm sure I'm going to need these for the exhaust on my Wagon. Do you just use the mitre function on the saw set to say 15 degrees and start cutting? It appears that you have about 1 1/2" on the outside of the pie piece whre the straight line is drawn. Is that about right?