econotig

[Slagman]

I don't see 30 amps as being a problem. I've welded .035 4130 in that heat range, only with a Lincoln Squarewave 175. It was a tandem bike to be exact. The only thing was, I was using the foot control, and I had the amps set to not go over 60. Never had a problem with going over that, but I was using an .040 tungsten with a lense. Skip on over to the projects page and I'll post a picture of the bike in the next day or 2, (assuming I can post it right.)

Slagman

[chip hayden]

i agree but, i might consider preheat and/or pwht where the tubing is welded to the bottom bracket or the headset. just because of the difference in mass might cause the welded area to cool too rapidly. chip.

[Slagman]

Actually a preheat is not needed for tubing of this size, but what needs to be done is just a quick heat in the range of 120 degrees or so, to get the "moisture" out of the base material. The head tube is the same size as the rest of the frame, .035. There is an insert that gets put in the headtube that will accept the fork. The bottom brackets are the thickest pieces, and the front seat post is actually thinner than .035", it tapers down to an .024". Post weld heat treatment is not needed, but stress relieving the joints is needed.

Slagman

[BugEyedValiant]

Hey airweld,

What kind of problems are you having with your Lincoln 205? Just curious because I havent heard much about them.

[airweld]

B.E.V.

I've had problems with the arc switching off when in AC mode. It will restart normally every time but will just snap off for no reason every once in a while. I don't use AC all that much so it's been just an annoyance so far. Very intermittent so hard to nail down. Other than that I really like the machine. I use a water cooled torch with a CK hand amptrol. Works for me. Scott.