The only advice I might have is to increase the Hz of you AC wave, this is supposed to concetrate the arc cone to give better arc stability, focus and penetration. the other option is to grind your tungsten to a shapper acute angel, however this wont help much if it keeps balling and spitting. I used Zirconiated and lanthanated Tungsten (3.2mm) on my jobs, 4-18" pipe 10 to 13mm thickness. the only other thing, we used was zero gap. 5083 with 5183 filler.
the starting is usually an issue, just to get that first puddle to form. Just make 100% sure that that starting spot is super clean, especially from surface oxides as this will , as you probably know, inhibit the forming of your pool. I would say start at the thicker section, form the pool and then drag it accros.
good luck, If you can Post some pictures, I always understand better with pictures
and where a dust mask or good ventilation. Al dust and vapours not too good!!
I've done some more coupons, and the results are much better. I think it was a combination of dirty base metal and my stickout. Even though the literature says you can extend your electrode as for as the diameter of the cup, I think on AC and approaching the amperage capacity of the electrode, you run into trouble from resistance heating of the electrode. Just a hypothesis at this point, but reducing my stickout has largely solved my troubles. Good advice on the respirator. At the shop I used to work at, I was the only guy with a respirator. I don't wear it so much with GTAW, but it is a faithful friend.
You are on the right track by changing the electrode stick out. We try to get our guys accustom to using as short as possible without blocking or affecting their sight of the arc and puddle. Most beginner aluminum tig welders struggle with adequate shielding gas and current on the initial start of the weld, in your case that would be the tacking.
I also think you are right on the high edge of the 3/32 tungsten. Try going to 1/8 and a bit more current. It takes 10-20% more current to tack on "cold" aluminum than it does to run the actual weld because of the thermal properties of aluminum.
I don't know if this was said above, but i am telling ya use a ceriated tungsten with a point. I know useing a point was said above, but best results with a point are with ceriated (2%ce) tungsten. Don't point it like you would stainless ,but just a nice steep point. What i mean by steep is so that the included angle of the 2 sides of the tungsten are at 90deg + or - just use what works for you. Ceriated is where it's at brotha!!
I've got a box of .125" ceriated tungsten and collets on the way tomorrow. As Kix said, I am going to a steeper included angle to get better penetration and longer tungsten life. Here is another stupid question. Are the stainless brushes typically used for pre-weld cleaning magnetic? It's my understanding that MOST stainless steels are nonmagnetic, but some are slightly magnetic. The brushes that the guy at the weldling supply store sold me are supposed to be stainless, but they are also magnetic. Could this be another source of clean base metal issues? I took an old one and left it in the rain for a couple of days and no rust, but the magnetism is still making me doubt the true nature of my brushes.
Hello devo, the magnetism that you have noticed is likely there due to the grade of stainless steel that was used to manufacture the brushes. I believe that 400 series stainless(used in many automotive exhaust systems) as well as some others will exhibit magnetism. Also, if I've got my stainless metallurgy correct, many of the ferritic stainlesses will exhibit magnetic qualities to some degree as well, depending on the amount of ferrite in them. Hope this helps to explain your question somewhat. Regards, aevald
The 200 & 300 series SS will become somewhat magnetic from work hardening, don't ask Me why. The brushes are 200 or 300 series. The ones I have are somewhat magnetic too.
Forum
