Good afternoon,
Today I turned down a job that I was unsure I was able to do. I have welded aluminum and fabricated some nice projects for customers, but nothing over 1/8" wall thickness. Well today I was called to go to a carwash and weld 3/8 thick aluminum bracket to 1/2" wall tubing. This would hold a few hundred lb equipment. My machine only goes up to 200amps. Any suggestions? Would helium do the trick?
Anthony
Man, if you're unsure about the work, walk!
I would want more than 200 amps to weld that, even with a preheat. A 50% He mix will help, but I'd also be concerned about the condition of the aluminum bracket. Sitting in a carwash, I'd anticipate a fair bit of contamination having seeped into that piece. Could make for an absolute nightmare of a job
I would want more than 200 amps to weld that, even with a preheat. A 50% He mix will help, but I'd also be concerned about the condition of the aluminum bracket. Sitting in a carwash, I'd anticipate a fair bit of contamination having seeped into that piece. Could make for an absolute nightmare of a job
I beleive it was new material. What concerns me is that it would be a fillet weld, and that takes heat.cj737 wrote:Man, if you're unsure about the work, walk!
I would want more than 200 amps to weld that, even with a preheat. A 50% He mix will help, but I'd also be concerned about the condition of the aluminum bracket. Sitting in a carwash, I'd anticipate a fair bit of contamination having seeped into that piece. Could make for an absolute nightmare of a job
What process, and amps would you recommend?
Would mig be better?
I would bevel the 3/8" material against the welding edge. I would use TIG happily, but I'd want up to 250 amps available to me. With multiple passes (3/32" filler until flush, then a 1/8" cover pass) I'd be confident in the weld. This would be beveled on both edges and welded on both sides.
I would turn the freq down to 50-60Hz, balance up to 75% on my machine, and crank that sucker up to FULL AMPs. You won't need the full amperage once you put a pass or two in as the part will be very hot. But a preheat, and full romp will get your puddle going.
I've used this method (above) a few times on Jon boat gill brackets. Welding 1/2" angle to 5/8" brackets. I used MAPP for a preheat, a no fill pass, then came back and smashed it with a full pedal and some filler. Waiting for the part to cool so I could lay another pass was the biggest trick. I had the luxury of doing this on my fixture table, in my shop, not in position in a carwash. I don't envy you-
I would turn the freq down to 50-60Hz, balance up to 75% on my machine, and crank that sucker up to FULL AMPs. You won't need the full amperage once you put a pass or two in as the part will be very hot. But a preheat, and full romp will get your puddle going.
I've used this method (above) a few times on Jon boat gill brackets. Welding 1/2" angle to 5/8" brackets. I used MAPP for a preheat, a no fill pass, then came back and smashed it with a full pedal and some filler. Waiting for the part to cool so I could lay another pass was the biggest trick. I had the luxury of doing this on my fixture table, in my shop, not in position in a carwash. I don't envy you-
I guess its a good thing I didnt take the job. Are you saying 250amp with helium? Dam. I need a bigger machine.cj737 wrote:I would bevel the 3/8" material against the welding edge. I would use TIG happily, but I'd want up to 250 amps available to me. With multiple passes (3/32" filler until flush, then a 1/8" cover pass) I'd be confident in the weld. This would be beveled on both edges and welded on both sides.
I would turn the freq down to 50-60Hz, balance up to 75% on my machine, and crank that sucker up to FULL AMPs. You won't need the full amperage once you put a pass or two in as the part will be very hot. But a preheat, and full romp will get your puddle going.
I've used this method (above) a few times on Jon boat gill brackets. Welding 1/2" angle to 5/8" brackets. I used MAPP for a preheat, a no fill pass, then came back and smashed it with a full pedal and some filler. Waiting for the part to cool so I could lay another pass was the biggest trick. I had the luxury of doing this on my fixture table, in my shop, not in position in a carwash. I don't envy you-
Guess it really doesn't really matter now, you had to turn down the job, but in the future, do you have a MIG/spool gun available? I'd prefer that over TIG for that size material, and that type job.
Lincoln Weld-Pak 180
Lincoln spool gun
Everlast PowerUltra 205p
AHP AlphaTig 200X
Assorted stuff
Lincoln spool gun
Everlast PowerUltra 205p
AHP AlphaTig 200X
Assorted stuff
Ive never used a spool gun. I have a esab 215ic which I can attach one to.ljdm1956 wrote:Guess it really doesn't really matter now, you had to turn down the job, but in the future, do you have a MIG/spool gun available? I'd prefer that over TIG for that size material, and that type job.
It’s true Spoolguns can do the work, but you’d better be darn sure you have it setup right. With TIG, you do get a better opportunity to insure penetration and fill.
You wouldn’t need 250 & 50% Helium to do that job, but it sure wouldn’t hurt to have both. The biggest concern from my perspective is the 1/2” tubing. Welding to it, you have little to notrol over the penetration, so you have to blast into it then stick the 3/8 to that. The 3/8 is the easy part, beveling and so on. But insuring a solid weld into a tube you may not be able to see into, that’s the trick. And the concern.
You wouldn’t need 250 & 50% Helium to do that job, but it sure wouldn’t hurt to have both. The biggest concern from my perspective is the 1/2” tubing. Welding to it, you have little to notrol over the penetration, so you have to blast into it then stick the 3/8 to that. The 3/8 is the easy part, beveling and so on. But insuring a solid weld into a tube you may not be able to see into, that’s the trick. And the concern.
And if the weld ever cracked and fell on a car, it would be a bad day for everyone.cj737 wrote:It’s true Spoolguns can do the work, but you’d better be darn sure you have it setup right. With TIG, you do get a better opportunity to insure penetration and fill.
You wouldn’t need 250 & 50% Helium to do that job, but it sure wouldn’t hurt to have both. The biggest concern from my perspective is the 1/2” tubing. Welding to it, you have little to notrol over the penetration, so you have to blast into it then stick the 3/8 to that. The 3/8 is the easy part, beveling and so on. But insuring a solid weld into a tube you may not be able to see into, that’s the trick. And the concern.
Yup, always a concern when welding anything that involves people. Thus, why I would never do a welding task I'm not 110% experienced with. I hate to walk away from money, but the risk is never worth the reward in my book. Besides, there's always another competent guy/gal out there with the right experience to do the job. Better he/she get paid then me get sued.Ant428 wrote: And if the weld ever cracked and fell on a car, it would be a bad day for everyone.