My tig welder has only high frequency only, what's wrong?

by Jay
(Longview WA usa)

I have had my Linde (L-tech)250 amp TIG welder for about 25 years and it is a wonderful machine. recently i tried to weld some mild steel and accidentally hit the tig/stick with my knee without realizing it. the amperage control was set to maximum and i use a foot control. when i started to weld (the welder started the weld at full power and then lost power. now i can only get high frequency. Since it was set on stick welding and the control was set at maximum power i assume i burned something out. I checked the welding power lead for continuity and it checks out ok any ideas what my problem is?
Jay

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I have used the same welder before and it was sweet.

It does sound like you may have fried a board or something.

I am not a welder repair guy and you will probably need to take it in to a local welder repair shop to get it fixed.

the not so happy news it that it might be expensive.

anyone else got any ideas?

Whats with everyone wanting me to run hardwire verticle?

by Ken

I have a coupon test later today, and the last 2 tests I have taken both wanted me to run hardwire vertical. I've been working the same job for 5 years and they would run people off for running downhill, let alone up.

Any tips for doing this?

Ken

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who knows why the sudden change in weld test requirements or details? It could be a new project that was evaluated by a welding engineer or analyst and it was determined uphill mig with bare wire was going to be used and therefor was going to be part of the weld testing requirements.

One of the main reasons bare wire mig is not used much for structural applications is because there are additional testing requirements according to AWS codes.

Flux core and Stick welding are deemed less likely to cold lap and therefore are acknowledged in AWS welding codes with pre-qualfied procedures. whereas all welding procedures are required to be tested and qualified with gmaw-s mig bare wire short circuit.

the technique boils down to correct settings, and staying on the leading edge of the puddle.

I made a video recently using 3/8" test plates with downhill root and uphill fill and cap.

hope it helps..

What's the best way to weld in a drilled hole.

Hi Jody, man great job on the site and everything. My question is how to best focous the arc at the bottom of a drilled hole in aluminum? The idea is to build it up to re-tap threads in it for a bolt. I was using a 2%thoriated tungsten on pulse I can't remember what freq now, but it was very hard to get a puddle at the bottom of the hole.

Regards Dave Reid.

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Dave,
a 2oo F preheat and a helium mix of up to 80 percent helium helps more than any setting.

i know what you are talking about. I once watched someone trying to get filler wire down in the bottom of a threaded hole with a skinny long tig cup.

he could fit the wire in, so he would puddle, stop, drop in bits of snipped wire, puddle again, and so on.

it was a slow go.