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I had to replace 2 cats in a cheby.  Not much room, but I removed the whole pipe and cut off the old ones. One was welded to the flange.This is what happens if you run the sawzall too fast cutting the cat off the flangeHere is a big gapAfter ONE passWhen coolSP 100, .023 wire, C/25 gas, settings E4.Last edited by David R; 11-15-2007 at 10:20 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Here is my best stick weld on the same job.  Nuttin to write home about.  1/16" 6013 DCEN 40 amps.Slag on Slag offFinished product.  I tacked everything in place, then took it back out and welded it.Installed David Last edited by David R; 11-15-2007 at 10:21 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Nice one! Exhuast is pretty fun to mess with but can be a pain.HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Nice job Dave. You make it look to easy Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:Dave,Thanks for trying your hand at stick again for the benefit of myself and others who currently have this as their only alternative.  Based on what I've experienced thus far in screwing around with stick on exhausts, I don't think the slip joints are too tough as long as you have tight fitup.  Without good fit, it gets kind of sloppy.On the butt joints, avoiding holes is difficult and the fitup and preparation is even more critical.  Here's what I found:1.  You need to have almost zero gap all around the circumference or its going to be tough.  Also when removing metalizing, be very careful to take off as little of the underlying material as possible because any reducting in thickness near the joint sets you up for blowing through. I'd go with a belt sander or a flap disc without a very agressive grit. (I'm dealing with 16 gauge pipe).2.  When I had problems blowing through, someone suggested weaving so I tried this and things actually got worse, even when moving very quickly across the joint.  I think that when you weave on such thin material the heat builds up too much and after less then an inch of progress, I started blowing big holes.3.  I had the best luck first doing stringer beads with 1/16" 6013 at 40A moving very quickly along the center of the joint.  Don't worry about not leaving enough filler behind at this stage as you can go back and put a cap on it once you've got the joint closed up.4.  On the first pass, I used both a drag angle (about 30 degrees) as well as an angle transverse to the joint (my stick was pointing across the joint from one section of pipe to another).  This seemed to allow better control of the heat.5.  If you do get holes, move on and go back and fix them later.  If you start getting lots of holes, you may have to do your first pass in shorter intervals letting the pipes cool between welds.6.  After the first pass is complete, clean it up and if necessary go back and cap it with 3/32.  With this pass, you can slow down a bit and weave a little (or do another stringer) and just use a drag angle (no transverse angle needed as was used in the initial pass).I'll post some pics of these steps when I get a chance.
Reply:Originally Posted by IrishBrewerDave,Thanks for trying your hand at stick again for the benefit of myself and others who currently have this as their only alternative.  Based on what I've experienced thus far in screwing around with stick on exhausts, I don't think the slip joints are too tough as long as you have tight fitup.  Without good fit, it gets kind of sloppy.On the butt joints, avoiding holes is difficult and the fitup and preparation is even more critical.  Here's what I found:1.  You need to have almost zero gap all around the circumference or its going to be tough.  Also when removing metalizing, be very careful to take off as little of the underlying material as possible because any reducting in thickness near the joint sets you up for blowing through. I'd go with a belt sander or a flap disc without a very agressive grit. (I'm dealing with 16 gauge pipe).2.  When I had problems blowing through, someone suggested weaving so I tried this and things actually got worse, even when moving very quickly across the joint.  I think that when you weave on such thin material the heat builds up too much and after less then an inch of progress, I started blowing big holes.3.  I had the best luck first doing stringer beads with 1/16" 6013 at 40A moving very quickly along the center of the joint.  Don't worry about not leaving enough filler behind at this stage as you can go back and put a cap on it once you've got the joint closed up.4.  On the first pass, I used both a drag angle (about 30 degrees) as well as an angle transverse to the joint (my stick was pointing across the joint from one section of pipe to another).  This seemed to allow better control of the heat.5.  If you do get holes, move on and go back and fix them later.  If you start getting lots of holes, you may have to do your first pass in shorter intervals letting the pipes cool between welds.6.  After the first pass is complete, clean it up and if necessary go back and cap it with 3/32.  With this pass, you can slow down a bit and weave a little (or do another stringer) and just use a drag angle (no transverse angle needed as was used in the initial pass).I'll post some pics of these steps when I get a chance.
Reply:Thanks Olddad. I wouldn't even screw with a butt weld and stick on that thin of tube.  I do agree, I used only a flap disc to clean up the pipe before I welded it.I had better luck with forehand  or push with the stick.Bottom line with the MIG its a joy to do exhaust.  With stick, its nothing but aggravating.Each time I do these experiments I learn something.   This time I reinforced something I already knew......Screw the stick for exhaust. It can be done, but....DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:you got to love the small migs for doing exhaust work, next thing is good old fashioned OA.   nice looking job there.Life is tuff,so be sharp  lincoln sp 100  cutmaster101  miller bobcat  miller 250 mig  $thousands in snapon