I've seen quite a few discussions that exhaust pipe and other thin gauge metal work is best left to a MIG welder. Most, if not all of the muffler shops have MIG welders. This is not just a post about my recent success with the stick welder, I want to go a little deeper into the usage and abilities of both types of processes.
I learned how to weld in high school shop class, brazing and stick. Out on the construction site, it was always stick because there was steel pipe on these jobs and that is the welder that was used for it. I never got certified but it wouldn't be a problem, most of the work I did was temporary or tack up for the certified welders but I laid a lot of bead in my time. So, of course, the first welder I bought for home use was a Lincoln Marquette Auto Pro 140 MIG welder, something I had no experience with. It worked fine, I built an air compressor, fixed a chain link fence and did a few other projects with it. But it just seemed like a hassle having to deal with wire feed, always having to cut the wire to a 1/4", changing it out for different sizes, having it bouncing against the work. I would just jam the gun head into the joint and hope for the best.
So then I saw a Craftsman/ Century Infinite Amp Adjustable 230/140 AC/DC stick welder on Craigslist for $150. I brought it home, cleaned it out, welded with it and sold the Lincoln for $400. Shortly after that, I spotted a Miller Thunderbolt XL 225/150, almost brand new, the newest model, for $300. I offered him $270, he accepted, I brought it home and sold the Craftsman for $250.
Which leads into the exhaust pipe welding. I have dual exhausts and the tailpipes were corroded at the muffler outlet. From the muffler to the engine it is all Flowmaster, solid as a rock. From the muffler to the tips, crush bent stock tubing of who knows what quality that the installer must have used to save money. I figured no problem, I'll just cut out the bad sections of pipe and weld in new. The rest of it would be wire brushed with a grinder and painted to get a few more years out of it (muffler shop recently quoted $700 for a replacement.) What I wasn't ready for was all of the holes that had completely rusted through, on the backside of the first bend, that was hidden from view while on the truck. No big deal, I had some 18 gauge sheet and formed a piece to cover the worst area. I used Lincoln Fleetweld 3/32" 6013 and set the machine at the lowest amps that Lincoln recommends, which was 70 DCEP. That was no good at all, blew a big hole in the old pipe in the first inch of weld, eventually settled in at 55 amps, I kept the rod angled so that the heat of the arc was focused on the new 18 gauge, using a quick whip to flow the deposited metal onto the old pipe. Weld an inch, stop and let the red glo get out of the bead, weld another inch.
Here is where the truly surprising part comes in, after covering the bad rusted out area with the sheet, I still had a half a dozen or so dime size or smaller isolated holes. Understand, my previous experiences have been with 1/4" wall pipe or 1/2" and bigger plate, 7018 all day. I said what the heck, let's see if we can fill them in. I turned the Thunderbolt down to 45 amps and using a spot or tack welding technique, I would hit the edge of the hole with just a touch, let it cool, no more red glo, hit it again, on the edge of the previous weld deposit. If the metal of the old pipe was no good, it would just blow out, making the hole larger. If the metal was good, I had a base to start working across the hole. You have to have the patience of a sphynx, if the new deposit was even the slightest bit red, it would blow out. When I got to the other side of the hole, same thing, bad metal would blow through, good metal you could see it temper from the heat. Then you fill it all the way in. Did I mention this was done with a stick welder?
Here is my Miller plug, this Thunderbolt is the finest, sweetest thing I've ever had the chance to work with. It would start the 6013 like it was a lift start TIG torch. I could have never did this with a MIG welder, I would have went insane. With the Miller, just get close to the work and there is your arc.
Butt Joint Weld exhaust pipe with a stick welder. My first joint was a slip, the old pipe inside of the new. Real easy drag weld, exaggerated rod angle leaned way out so that you aren't directing the heat from the arc straight into the old pipe but digging at it along it's "top." Weld an inch, let it cool, weld another inch. My second joint was a butt weld, totally unprepared for, I had planned on sliding it into the old pipe and doing another fillet weld but the outlet from the muffler was double walled pipe. Bad news, this is being done under the truck, the gas tank is in the way from accessing the other side of the weld, there are two exhaust supports right in the way. Oh well, what can you do but deal with it? Fitted the joint up as best I could, tight all the way around except for an 1/8" gap on the closest side and a 3/16" gap on the bottom. I turned the T-Bolt up to 55 amps and went back to the spot/tack weld technique to fill the gaps, couldn't hardly see what I was doing because of the obstructions and lack of sunlight. Overhead welding a 3/16" gap in thin wall exhaust pipe with a stick welder. Laying on my back, holding the shield straight with my other hand. My head and the shield wedged in between the driveshaft and the gas tank. The touch start arc of the Thunderbolt made it all possible.
In conclusion, I can't see why anybody would want a MIG welder. Don't get me wrong, the 110V plug in is way more convenient and the ability to weld continuously without having to change out rods is nice but I can switch to aluminum, cast or stainless welding of various thicknesses by just pushing the clamp on the stinger and inserting the proper rod. And now that I know thin gauge sheet metal is not only possible but very easy, I'll never look back.
I learned how to weld in high school shop class, brazing and stick. Out on the construction site, it was always stick because there was steel pipe on these jobs and that is the welder that was used for it. I never got certified but it wouldn't be a problem, most of the work I did was temporary or tack up for the certified welders but I laid a lot of bead in my time. So, of course, the first welder I bought for home use was a Lincoln Marquette Auto Pro 140 MIG welder, something I had no experience with. It worked fine, I built an air compressor, fixed a chain link fence and did a few other projects with it. But it just seemed like a hassle having to deal with wire feed, always having to cut the wire to a 1/4", changing it out for different sizes, having it bouncing against the work. I would just jam the gun head into the joint and hope for the best.
So then I saw a Craftsman/ Century Infinite Amp Adjustable 230/140 AC/DC stick welder on Craigslist for $150. I brought it home, cleaned it out, welded with it and sold the Lincoln for $400. Shortly after that, I spotted a Miller Thunderbolt XL 225/150, almost brand new, the newest model, for $300. I offered him $270, he accepted, I brought it home and sold the Craftsman for $250.
Which leads into the exhaust pipe welding. I have dual exhausts and the tailpipes were corroded at the muffler outlet. From the muffler to the engine it is all Flowmaster, solid as a rock. From the muffler to the tips, crush bent stock tubing of who knows what quality that the installer must have used to save money. I figured no problem, I'll just cut out the bad sections of pipe and weld in new. The rest of it would be wire brushed with a grinder and painted to get a few more years out of it (muffler shop recently quoted $700 for a replacement.) What I wasn't ready for was all of the holes that had completely rusted through, on the backside of the first bend, that was hidden from view while on the truck. No big deal, I had some 18 gauge sheet and formed a piece to cover the worst area. I used Lincoln Fleetweld 3/32" 6013 and set the machine at the lowest amps that Lincoln recommends, which was 70 DCEP. That was no good at all, blew a big hole in the old pipe in the first inch of weld, eventually settled in at 55 amps, I kept the rod angled so that the heat of the arc was focused on the new 18 gauge, using a quick whip to flow the deposited metal onto the old pipe. Weld an inch, stop and let the red glo get out of the bead, weld another inch.
Here is where the truly surprising part comes in, after covering the bad rusted out area with the sheet, I still had a half a dozen or so dime size or smaller isolated holes. Understand, my previous experiences have been with 1/4" wall pipe or 1/2" and bigger plate, 7018 all day. I said what the heck, let's see if we can fill them in. I turned the Thunderbolt down to 45 amps and using a spot or tack welding technique, I would hit the edge of the hole with just a touch, let it cool, no more red glo, hit it again, on the edge of the previous weld deposit. If the metal of the old pipe was no good, it would just blow out, making the hole larger. If the metal was good, I had a base to start working across the hole. You have to have the patience of a sphynx, if the new deposit was even the slightest bit red, it would blow out. When I got to the other side of the hole, same thing, bad metal would blow through, good metal you could see it temper from the heat. Then you fill it all the way in. Did I mention this was done with a stick welder?
Here is my Miller plug, this Thunderbolt is the finest, sweetest thing I've ever had the chance to work with. It would start the 6013 like it was a lift start TIG torch. I could have never did this with a MIG welder, I would have went insane. With the Miller, just get close to the work and there is your arc.
Butt Joint Weld exhaust pipe with a stick welder. My first joint was a slip, the old pipe inside of the new. Real easy drag weld, exaggerated rod angle leaned way out so that you aren't directing the heat from the arc straight into the old pipe but digging at it along it's "top." Weld an inch, let it cool, weld another inch. My second joint was a butt weld, totally unprepared for, I had planned on sliding it into the old pipe and doing another fillet weld but the outlet from the muffler was double walled pipe. Bad news, this is being done under the truck, the gas tank is in the way from accessing the other side of the weld, there are two exhaust supports right in the way. Oh well, what can you do but deal with it? Fitted the joint up as best I could, tight all the way around except for an 1/8" gap on the closest side and a 3/16" gap on the bottom. I turned the T-Bolt up to 55 amps and went back to the spot/tack weld technique to fill the gaps, couldn't hardly see what I was doing because of the obstructions and lack of sunlight. Overhead welding a 3/16" gap in thin wall exhaust pipe with a stick welder. Laying on my back, holding the shield straight with my other hand. My head and the shield wedged in between the driveshaft and the gas tank. The touch start arc of the Thunderbolt made it all possible.
In conclusion, I can't see why anybody would want a MIG welder. Don't get me wrong, the 110V plug in is way more convenient and the ability to weld continuously without having to change out rods is nice but I can switch to aluminum, cast or stainless welding of various thicknesses by just pushing the clamp on the stinger and inserting the proper rod. And now that I know thin gauge sheet metal is not only possible but very easy, I'll never look back.
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