To Clean or Not to Clean when TIG Welding

I'm taking a TIG welding class which is: Watch 4 videos on TIG
welding and go to the lab. The instructor comes around from time to
time and offers suggestions... no demos, unless maybe you ask.
Doing some lap joints on CS HR 16 gauge plate, 3/32 tungsten,with
filler he said 80 amps... I finally found out that it should be 1 amp
per .001 thickness. Anyway I kept having trouble at class and since I
also have a machine at home I get to practice. I now at home, have it
set at 65 amps and using a very sharp tungsten grind I can get some
really nice looking welds.
At home I also grind off the mill scale with a flap disk, at class
instructor never seemed to indicate cleaning of oil or grinding was
needed. I think I read on here or elsewhere this was needed and along
with wiping down the welding rod with acetone. Am I right or wrong??
BTW When I was MIG welding aluminum (at home) I used a stainless
steel wire brush and acetone to clean off the plate... welds looked
very nice.
Comments Please. B.G.
Reply to
MachineShop
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There's no flux used in the TIG process, so cleaning would be necessary. The only cleaning action is the HF for aluminum. Are you using the same type of tungsten in each location? Since you have a machine at home, I would think that you do.
Reply to
Thomas Kendrick
My experience says that TIG welding requires very clean metal. Lane
Reply to
Lane
Cleanliness is an important part of good TIG welds. Cleaning off the mill scale in your weld area with a flap wheel or grinder seems like a requirement to me.
A stainless brush is also a good way to clean up other metals for TIG. When I get coloration from stopping a weld, I usually clean it off with a stainless brush before I resume welding. I also clean up with Lacquer thinner or acetone before welding, especially if the metal is oily.
I usually don't bother wiping down the welding rod, although some types of high purity gas system and vacuum system welding require it (I don't do those any more).
Good Luck,
Bob
Reply to
MetalHead
When the instructor said 80 amps, I think he meant 80 amps setting on the welder. With the amptrol you don't have to use the full 80 amps. I always set the machine so I can go to a bit current than I use while welding.
As far as cleaning........ What kind of trouble were you having at class? Is the puddle is not wetting the base metal easily? Does the puddle sort of suddenly move forward, starts and stops? Or does it creep forward as the metal melts?
On lap joints I would take off the mill scale. On veed butt joints I probably would not. Might if the weld was critical, but I doubt that you will run into that on hot rolled steel.
Take a clean paper towel and wipe off a welding rod. Is it removing oil and dust? If it is, repeat with another paper towel and acetone. Is that removing more dust and oil. Generally I don't believe you need to wipe the welding rods, and would think that wiping with a dry paper towel would be more than good enough. But if you are removing stuff off the surface with the acetone after wiping with a dry paper towel, then you need the acetone. If it doesn't look like wiping with a dry paper towel is removing anything, then why do it.
The instructor may think that your time at class is best spent getting motor skills for handling the torch and rod. Time spent cleaning is time not welding. So ask him about cleaning rods and mill scale.
Dan
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Reply to
dcaster
Hi Dan and others... I guess one problem was not getting the puddle to start, even with increased heat, Now looking back I'd say that the scale or oil on the plate was that problems cause. Also now the holes in the weld at times and sparking I would trace back to the not clean enough. The instructor told me that those were caused by bad spots in the steel?
At home I have been cleaning the plate with flap wheel and haven' t had those problems. I think the answers here have helped to confirm what I suspected. My new welds now look great... thanks to you and others!!! Thanks again for taking the time. B.G.
Reply to
MachineShop

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