High Freq on stainless?

[trukfan24]

Hello gentlemen, and if there are any ladies, hello to you too. I've been reading posts on here for awhile, and I know there are some exceptional welders on this forum that ought to be able to answer my question. My question is; does using the continous high freq setting for TIG welding stainless do anything to help stabilize the arc, or does it really do nothing. I ask b/c when I interviewed last week for what will be my new job, I took a weld test and out of habit, I switched the high freq from at start up only to continous. I think I did it b/c I've been doing a lot aluminum repair w/ tig at my current job. According to the guy who gave me the test, I laid the best beads of all the applicants for this job, but I don't think it was b/c of having the high freq on. If it matters, the machine was a Syncrowave 250 DX. I looked in my text book from when I was in school, and I couldn't find any reference about the up or downsides of running it that way. Any and all input would be greatly appreciated.

[Drag Racer]

All we use at work is the high frequency start when welding stainless. We also use Syncrowave 250's. After welding aluminum I have forgot to turn off the high frequency, and other than making more noise, I don't think it makes any difference on stainless.

[precisionworks]

Welcome aboard! Elkhorn, Iowa? Been there, if that's your home -- great food and a neat windmill.

Most of the reading I've done on hi-freq indicates that it produces less than perfect weldments. Lincoln had an article in their e-newsletter http://www.lincolnelectric.com/knowledge/articles/content/tigseriespower.asp that mentions that "... in most DC TIG machines the high frequency remains on for a long duration and with a high intensity until the arc stabilizes. This can create tracking marks on the weld surface which, for some applications in the aerospace industry, is viewed as a weld rejection."

In AC mode, the hi-freq needs to stay on, as the polarity changes many times each second & the hi-freq helps stabilize the arc. In DC, once the arc is established by ionizing the airspace between tungsten & work (same thing a lightning bolt does on a much smaller scale) it's no longer needed.

[Paul Seaman]

The high-freq is only needed for arc start, on SS but I am unaware of any ill effects for using it continuous.

[tigman250]

The high-freq is only needed for arc start, on SS but I am unaware of any ill effects for using it continuous.

i agree

i have forgotten it on before and have noticed little diffrence other than the sizzling noise of the HF on the contacts

[trukfan24]

I did notice an increase in arc noise, now that I think about it. But, since it appears to do nothing beneficial, I'll just do it as always. By the way precisionworks, my hometown is actually Elkhorn, Wisconsin. Same name, no neat windmill. Oh well, right? But thanks to all for their input.

[precisionworks]

It's funny, some days every weld is perfect, dead nuts on. Vertical, overhead, doesn't matter. X-ray quality.

Other days, JB Weld might be a better choice........ :D