Guys -
I'm hoping someone here will have some ideas for me. I'm a bike builder, and a TIG welder, and I've recently (in the last several months) started having troubles with both my Maxstar150STR and Dynasty200 (both air/inverter machines).
The original thread (on a bike building forum) is here, along with some pictures:
http://www.frameforum.net/forum2/index.php?showtopic=2938Here's the original post:
Ok, at this point, this issue has confounded me, the good folks at General Air, my old welding instructor, and everyone else I could think of to ask. Looking for any kind of weird idea at this point - I am baffled.
The symptoms: I'm getting greyish, lumpy deposits on the surface of my tig welds. Glowing embers are visible in the weld pool while welding, as well. Clearly, something non-inert is getting to the weld, but I'm stumped at this point as to what it might be. The arc also has a tendency to wander and is relatively hard to control. Strength of the joint seems unaffected - I've done some destructive testing to make sure. But the appearance is sub-par from what I'm used to doing. I'll try to post a picture or two tomorrow.
Solutions I've tried with no effect, in no particular order:
-Check (no leaks) then replace regulator, all hoses, torch body and parts.
-Replace entire welder (hey, I always wanted a Dynasty anyway...)
-Use different type (ceriated and thoriated), size (3/32 and 1/16), and brand of tungsten.
-Use different gas cups and lenses of all different sizes.
-Change argon flow rate to torch from as low as 5cfh to as high as 35.
-Replace argon tank (multiple times) and try argon from another supplier.
-Replace tungsten grinding wheel with new ($$) diamond wheel.
-Sharpen tungsten to fine point, sharpen tungsten then grind flat, etc. I've pretty much tried every shape of grind you can think of.
-Close all doors/windows and completely eliminate any possibility of drafts (it's notable that I never used to have this problem when welding with a fan running on a hot summer day).
-Use different type/size of weld rod (ER70S and 880t in .035 and .045).
-Use different cleaning procedures (acetone vs denatured ETOH, stainless wire brush vs emory cloth vs scotchbrite vs 3m metal cleaning pads).
-Use different tubes (happens with 4130, everything made by True Temper, all Nova/Columbus stuff that I have, and even old Tange prestige).
-Backpurge/don't backpurge tubes.
-Change welder settings all over the map - from 70 to 120 amps, pulse rates from .5 to 2/second, different background/peak, etc, etc.
-Swap polarity.
-Keep all hoses/lines in warm, dry place for 2 weeks to make sure no moisture is inside.
-Move entire welding setup 10 feet to another location in the shop.
-Clean welding table/replace ground clamp to ensure good ground.
-Probably a few other things I can't remember now.
I've done some sample welds using other equipment at other locations and I have absolutely no issues, so it's not anything about torch angle or technique (and given that nothing about my technique changed in the last 3 or 4 years, whereas the problem started about 4 months ago, I doubt that it's a technique issue).
I'm pulling my hair out on this. Any clever ideas?
-Walt