Well, thanks everyone for all that! Very helpful. I do still have that PT185, but I'm thinking that if I cut a groove and not bite off more than I can chew I might be just fine. I don't have any AR/He mix. Only pure Ar in my shop but it sounds like the He is just to get more heat transfer into the w...

I've been asked to weld some copper bus bars together to lengthen them. The bars are about 1/4" thick and apparently pure copper. Either way, I can find out what exactly they are made of. Can I TIG weld copper just like aluminum? If I can, what rod, anything particular I need to be aware of? Pu...

Thanks all for your answers. Kinda makes sense that you need Argon but wanted to check anyway...

Jon

If I can oxy-weld mild steel with just heat from the torch and a filler rod (I.e. no flux, no inert gas, etc.) why can't I TIG weld mild steel without Argon? I ran out of Argon and ordered too late to get a refill (I'll probably go down to Home Depot and get some tomorrow) and need to weld up some m...

cj, You made me laugh! But this is all very good advice. Thanks for clarifying "wash" and "peen" - this makes total sense to me now. I believe my main shortcoming is impatience. I can't always wait for the ally to cool and I'll keep going and ruin my weld. I sometimes dip my tung...

cj - Got it. Fortunately this is a brand new casting so I probably won't have too much trouble with it in that sense. When you say 60* grind on the tungsten, you mean a little blunter than usual, right? Or do you mean sharper? I'm assuming that I'd still cut a flat crayon end on the point anyway see...

cj737, Great. I've got 3/32" 5356 but I can't adjust my PT185 to 50 Hz. So I'll stick with 60Hz, leave my balance at 70/30, no pulse, hit it with a 3/32" lanth electrode, normal Argon flow (15-20CFH) and see how I do. I somehow got the idea that welding cast ally to 6061/6063 was a bit of ...

I'm going to be welding a cast ally piece to the end of a stick of 2" OD ally 6061 tubing.

Any pointers before I take the plunge?

Jon

cj737 - Good. Well that answers that. Thanks much (again).

Jon

I’m welding 1/4” x 1” 6061 ally, double-V-groove butt welds with each piece at 90 degrees to the next to fabricate 48” x 48” frames for holding light diffusion material. If you’ve followed my recent posts you will already know this. Each piece of 48” ally has a 45 degree mitre cut at both ends to ma...

Thanks guys...

Least I’m learning...

Jon

So I'm making a jig, the base of which is a 12" x 12" 16ga piece of stainless steel. Don't know what alloy. I cut it out of an old sink counter. I cut the SS piece on a bandsaw and so it had rough edges. Simple enough, I thought, set the TIG machine for DC-, about 40 amps with a slow pulse...

Copy that!

Mick and cj - Hey, thanks a lot. After I posted, I was thinking that SS would probably be the way to go. I didn't consider using tube but I'll probably go that route. There are a lot of SS flavours. I have a ton of 308L rod (1/16", 3/32" and 1/8") that I bought when I purchased my mac...

I'm going to be building some 48" x 48" fabric frames from 3/8" rod. These frames hold thin fabric that is used to diffuse light on film and video sets. They have a 6" perpendicular-to-the-frame handle that locks into a stand. Often these handles are under the strain of the entir...

Togga, Funny you should mention the foot pedal. Sometimes, I'll stomp on the pedal and nothing will happen. Once I jiggle it a little bit, the welder gets going. So maybe it IS the pedal that is giving me the problem. I opened the machine up a couple weeks ago and checked the spark gap, blew it out ...

Togga - I'm having similar problems with my PT185. It's almost like I'm making it work too hard (even though I'm not) and it will stutter and give me all sorts of intermittency, coughing and spluttering while I'm trying to maintain a steady arc. I'm sending it in to a repair shop next week. I'll let...

Yep - we're back to getting a bigger machine again... Mine tops out at 185amps. Fortunately, that 5/8" rod is only 7" long so it heats up pretty quick-like. I was drilling a hole into the 5/8" and doing it that way. But the 5/8" is the "handle" for the frame and it take...

cj and BillE, Thanks for your feedback. On the tungsten and why I'm using red - that's a good question. I always thought red was preferred. Then I learned that blue tops all of them. I have tried brown with some success but never grey. I'll try and get my hands on some and try it out. Agreed on that...

I'm welding 1/4" AL rod to 5/8" AL rod, perpendicular, like the picture shows. I'm doing this with a 3/32" red tungsten, 3/32" 4043 filler rod, 50/50 penetration/cleaning, no pulse, 100% Argon at about 125 amps. Trouble is, my arc is so wide that even though I am attempting to di...

Toggatug, Thanks for your input. Nice to know that there's someone out there who has (or had) the same machine as me. Frankly, I think that trying to weld 1/4" AL is maxing this Lincoln out. cj737 already pointed that out but I've had to keep trying because I don't see a new machine on the hori...

Great - thanks guys.

I'll get some of both those rods, 5356 and 4943.

Jon

Here's some pix:
First two were okay. Third shot shows grain (even if it is a bit out of focus).

Guaranteed I'm not the first person to post with a problem with grainy looking AL welds. I'm doing these aluminum frames from 1" x 1/4" 6061. Tricky welds because the welds themselves are only about an inch long and then you're off the end. Found a neat trick to prevent blowout though: wel...

Yeah - I think at the end of the day it's the bad workman who blames his tools... And all the best welders started out with whatever they could get their hands on, right? So I've got my hands on a Lincoln PT185 and should be happy that I've got a machine at all. So, my butt is going back in the chai...