[gexas]

when tig welding stuff like aluminum usually your are doing relatively small stuff. What do you guys clamp too? I try to clamp directly to most stuff but at times it is too small and either the clamp from the welder gets in the way or it gets in the way of my arm moving around with the torch or the filler wire. I have a home made welding table that is steel plate. When I mig weld steel, at times I just clamp to the the table and just clamp the job to the table. Can you or do you do the same when tig welding aluminum.

Thanks,

E

[Canuck]

Hey E,

I have a welding table and TIG and MIG with the clamp attached to the table via a braided copper wire. Works like a charm.

[gexas]

so you have good conduction through the table and into the work piece and it is good enough to tig with right?

just want to make sure i understood your answer.

thanks,

E

[Canuck]

so you have good conduction through the table and into the work piece and it is good enough to tig with right?

just want to make sure i understood your answer.

thanks,

E

MIG is more of an issue than TIG...but with the heavy braid on the table, I have no conduction problems.

[pro mod steve]

At school they had a vert pipe bolted to the floor with the work table welded to the pipe. The ground was clamped at the bottom of the pipe on all machines. I never had any grounding issues this way.

[jakeru]

On a couple occasions now, I have forgotten to clamp my ground to *anything*.

Surprisingly, there are times when I don't even notice and the weld proceeds normall. Other times the weld is going OK, when I notice "hey! What's that smell?" and something is burning or melting that's not supposed to be. The first time, it was one of the rubber washers insulating the spring of my ($10 harbor freight, brass style 400 amp) ground clamp. (That was because the ground clamp was arcing to the welding table right near where the rubber spring washer was.) The second time I forgot to clamp my ground, I was in the middle of my weld bead, and suddenly noticed a real hot spot in the palm of my torch hand glove, which made me stop welding all of the sudden. I also noticed an odd plastic burning smell, and found one of the plastic zipties holding an on/off switch to my torch handle got melted away, and was smoking a bit. (The ground path apparently found its way into the palm of my welding glove, across and into the the steel pin of the on/of switch pivot near the ziptie, and then who knows where else...) Apparently my inverter welder deals with high resistance pretty well.

So in summary... first and foremost, just remember to clamp the ground to something.

-----

On small aluminum parts, I have made the mistake of clamping to a small aluminum part before, and then go to weld it, to have the heat of welding with pressure of the ground clamp collapse the part. (Aluminum being "hot short", means it can't take much stress when it gets very hot). What I usually do now to weld a small aluminum part, is clamp to a bigger piece of aluminum, and set the smaller piece I'm welding on top of it.

I would love to try a "welder's finger" aka "third hand" for grounding and also holding small parts better sometime... There is a page on this site that describes the "third hand" on the lincoln motorsports class review... check it out: (scroll down towards the bottom) http://www.weldingtipsandtricks.com/mot ... lding.html

If you find that a small, ungrounded aluminum part is arcing on the grounded welding table (or grounded other piece of metal), then putting some weight on it with a welder's finger / third hand would help eliminate this problem.

Richard Finch (in "Performance Welding Handbook, 2nd Edition", motorbooks international) says "The metal finger should have some weight to it to provide stability and make a clamping type electrical connection. I usually make several welder's fingers out of 3/8 inch steel rod and 1/2 inch diameter steel rod."

[jakeru]

I made up a couple welder's fingers / welders third hands today:
http://forum.weldingtipsandtricks.com/v ... ?f=9&t=728