Erratic start with foot pedal

[everlastsupport]

The micro-switch is the on off switch, pins 1 and 2. Just like the trigger on the torch handle.

[jtybt]

Hmmm, so that doesn't sound like it would do anything good or bad, as long as it's working, huh.

Does it sound like changing the pot will do any good? Looks like I can cut away almost 2" in overall height from the pedal so I'll have to disconnect the pot and switch anyway.

Would connecting the wires in the same order work on a new pot?

[everlastsupport]

Hmmm, so that doesn't sound like it would do anything good or bad, as long as it's working, huh.

Does it sound like changing the pot will do any good? Looks like I can cut away almost 2" in overall height from the pedal so I'll have to disconnect the pot and switch anyway.

Would connecting the wires in the same order work on a new pot?

Most pot like that have the common in the middle, so it should wire up the same way. Just make sure the center in the common.

[performance]

OK,
1) what is your gas?
2) what tungsten are you using?
3) What amps are you trying?

Have you tried it with the tig torch switch to isolate the issue?

[jtybt]

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"Cleats for boat. 1/2" 316 tubing to 1/8" 304 base plate. 2T 98amps straight argon @8L. 1/16 Thoriated. Everything cleaned with lacquer thinner. Sharpened on grinding wheel. Probably the cause of contamination.

Starts off like fireworks. Stuck and broke the tip off the tungsten and had a relatively clean start. Gonna try sharpening on a new flap wheel. Ran out of 1/16 tungsten, going to 3/32."
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I usually use the torch button with pulse but tried the pedal for this project. Just went back to the button. I get a harsh/strong arc at start-up sometimes but not the fireworks like with the pedal.

I just don't get that nice little 'ball of light' all the time. It's a pretty erratic starting arc no matter what I use.

[performance]

Flap wheel? Why are you sharpening your tungsten with something usually high in aluminum content i.e aluminum oxide? A harsh start can be from a sudden burst of gas. Increase preflow time. Also sounds like possible bad gas. 1/16 tungsten is WAY too small unless you are welding at something less than 20 amps, especially on aluminum. It will cause bad starts. I know what the "charts say" from the big guys, but they also recommend using pure tungsten too for aluminum.

[jtybt]

Never occurred to me about the aluminum oxide. I'll check. Otherwise, I was using my grinder. How about a angle grinder wheel.

I'll go play with the TIG after I finish buffing the cleats a little.

I have pre-flow set at about 10 oclock

[Wrenchtamer]

At my shop we have a precision tig 275 that I use everyday. The tungsten I use in it most of the time is probably the diameter in question. I have not mic'd it, but I was curious today and I held it up to a 1/16 piece of filler and I would say it is roughly half the diameter. Now this is a transformer based machine so this may not apply to our machines (I have not tried it in the 256) but I have been doing stainless headers with it for the last week and a half or so, and today I did a steel repair at 107 amps. That tungsten is awesome. It's a little tough to sharpen, you kind of just scrape it lightly on your abrasive of choice and it's ready. it's so slim that it doesnt really make as big of a difference if the point is not perfect. I had to weld from the inside of some 2.5 inch tube and it was nice for that. I think you can get a 3 pack from airgas if you want to try it, It is NO good for ac, tho.

[jtybt]

The 1/16 tungsten was some I got from Harbor freight. The SS tubing was .040 wall and the base plate I was welding to was 1/8". I ran out of the 1/16 so I used 3/32 to practice laying a bead on the edge if 1/8" plate. I just need more practice.

[Wrenchtamer]

I'm not sure how much the chainsaw kit costs, but you might want to check this out http://www.harborfreight.com/3-inch-...her-94071.html
It's a little mini grinder for 30 bucks. The on epictured is a little different than mine, mine has a knob on the front to control rpm. I made a little guide on mine to give a nice point on 3/32 and 1/16. It comes with one semi fine stone and one polishing wheel and had a little dremel type rotary attachment on it. (I took that part off.) the refill kits with new stone and polishing wheel are ten bucks I think. I bought mine a year ago and still on the first stone. I use it only for tungsten. believe it or not I have actually used the polishing wheel to finish up the tungsten and it gives it a nice chem-sharp type of point. Just have to hit it with some acetone or solvent before you weld but it works real nice.

[everlastsupport]

Charlie,

Run your gas at 8-10 if you're using our metric gauge, 12-14 otherwise, make sure there is no breeze of any kind..

Also, Mark hit the nail on the head. Bump the electrode size. The charts are not always your friend.

The gas is pure argon right? Is the tank a rental tank? The yellow ball sounds like bad gas or your electrode is contaminated.

I know this is a repeat, just want to make sure you weed out the problem.