"Too Hot"!: Is key in destroying a tungsten. I imagine an ill experienced individual would accidently set the amperage too high. Not much info to go on, so let me ask you a question, assuming you are properly dressing and preparing your tungsten, proper gas and volume, proper/clean cup, collet, collet body, when you strike an ark do you start out slow and let the metal heat up slowly or do you hit the pedal to the metal and start at full amperage. If you do that, notice that your tungsten when extremely hot will began to spray; at this time you have probably ruined about 1/2" of tungsten. Tungsten is like any other steel in one common denominator, you over heat it, the molecular structure changes and it is no longer as effective and efficient as it was when it was new. You can't always rush TIG Welding, like you can if your wirefeeding or stick welding. "Crank er up and go"!
When someone ask me what is the most important thing to remember when learning to TIG; My response is generally; Get Comfortable; preferably at a good workbench with a chair to sit in at the proper hight. When you strike your arc, just give enough pedal to get a good solid start. Make sure if your working on ferrous metal use DC- and make sure your hi freq. is on start, and not continuous. Taking your time (MOST IMPORTANT) watch your arc and slowly increase your heat, let everything ie. tungsten, base metal; heat up together. Give the inert gas time to do it's cleaning action. By holding an arc on your work, but not immediatly creating a puddle you can see how the stainless will change colors as the gas and arc work together. Eventually the base metal will heat up and you will find an exact position on your pedal where you can begin to make a puddle. When your puddle becomes the size and consistency to add filler begin welding making fine amperage adjustments continously.
It's my opinion that there are more welders out there that don't realize, just how destructive and degrading, that too much heat have on steel, iron, aluminum, whatever. Over my many years as the EFFIN WELDER (got that from another thread) (In the model shop that was my name) I've had to harden steel, anneal steel, bend steel, even bow steel with just a rosebud and water! I have learned over that time that the hotter and the more molten I make metal, there is a direct correlation to the quality of the HAZ, and the actual joint strength.
BTW What size base metal did you say you were practicing on?
One other thing, stainless gets pretty dirty while welding and is really one of the most unstable metals when welding. I highly recomment back purging to insure proper penetration and a good bead on the backside. I use Solar Flux Type B to back all of my stainless. After brushing the residue I can use a pickling gel to clean it and restore the shine and color. Can't even tell it's been welded.
http://cgi.ebay.com/Solar-Flux-Stainless-Steel-TIG-MIG-ARC-Welding-Material_W0QQitemZ220540072307QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3359367173Take Care:
Steve
Forum
