This is a repeat of a post I made to a bicycle building forum - you can find that thread (including a couple of photos) here: http://www.frameforum.net/forum2/ind...opic=2938&st=0
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. See the pictures in the frameforum thread for some of the worst examples. This problem began about 2 months ago for no apparent reason - I've been using the same materials and techniques with no problems since early 2003.
The problem occurs on both my (brand new) Dynasty 200DX and my older 2003 vintage Maxstar 150STH.
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.
-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?
Results 1 to 9 of 9
02-28-2007, 02:13 PM #1Junior Member
- Join Date
- Feb 2007
Dynasty 200 contamination issue - help!
02-28-2007, 03:14 PM #2
Sounds like you have covered all the basics....here might be a couple other ideas.
Try a gas lens for your torch....if you dont have one already.
Avoid any kind of abrasive, the particles can imbed and cause fits. Try using files and carbides only.
Avoid any solvents that are petroleum based, sometimes that can cause an issue.
If all else fails buy a nice OA torch setup
-Aaron"Better Metalworking Through Research"
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02-28-2007, 03:17 PM #3
Walt, I looked at your photos, and I have a Dynasty 200DX. My question is are you welding with AC? That would give the little sparks you are seeing, also the gray haze around weld when the arc is positive. Just a thought, but steel with AC tig is not pretty...Hope this helps, Paul
02-28-2007, 03:59 PM #4Senior Member
- Join Date
- Jan 2006
Walt, As was suggested, did you have your incoming power checked out? And did you take your machine to another location to try it there. Since this also affecetd your Maxstar, and you have eliminated all other variables, I would suspect your incoming AC.
02-28-2007, 05:46 PM #5Junior Member
- Join Date
- Feb 2007
I have taken the whole setup to General Air (our local welding supply) and the problem is exactly the same there. I'm thinking this has to be an issue with the cleanliness of the metal rather than the machine, because we hooked up a Lincoln PrecisionTig and found the same problem.
Power in my shop is apparently good, on the plus side.
02-28-2007, 07:54 PM #6
Walt, just a thought, did you use the same filler metal at General Air as you use in your shop. When I looked at the photos enlarged, the gray islands looked kinda like Silicon Islands. Sorry about the AC comment, forgot that the Maxstar is DC only. Are your filler rods copper coated or bare??? Hope this helps, Paul
02-26-2008, 09:01 AM #7Senior Member
- Join Date
- Jul 2007
- Southern NH
1. Bad lot of base metal. You may have some base metal with incorrect metalurgical properties.
2. Bad lot of filler rod with incorrect metalurgical properties.
3. Cleaning techique of the base metal or filler rod. Abrasives leave behind contaminents, liquid cleaners can leave behind contaminants, etc. Maybe you have a bad lot of cleaning supplies (abrasives/cleaners).
You said that you made sample welds at other locations with no issues. So, I recommend that you merge the characteristics of the good sample welds with the bad welds.
1. Can you take everything where the good sample welds were made, and make those welds in your shop.
2. Can you take the base and filler metal from the good sample welds and use your equipment to make good sample welds in your shop
3. etc., etc. Until you identify the item that is causing the problem.
The important thing in tracking down this kind of thing is to stop feeling baffled. As humans, we often are baffled at a problem that we unconsciously stop looking for a solution because deep down inside it makes no sense and we feel defeated by the problem. Let's face it, *SOMETHING* has changed, so *STOP* feeling baffled, and *START* being a scientist and identify the problem.
02-26-2008, 09:03 AM #8Senior Member
- Join Date
- Dec 2007
Well I don't even know how to tig weld! But I have read so much here in preperation to learn how to, that it struck me that the only thing really not mentioned was the filler. I know stick rods and wire degrade if allowed to absorb moisture or oxidize... just a thought
I am an avid biker so the thread caught my attention...
02-26-2008, 11:27 AM #9
Miller Dynasty 700...OH YEA BABY!!
MM 350P...PULSE SPRAYIN' MONSTER
Miller Dynasty 280 with AC independent expansion card
Miller Dynasty 200 DX "Blue Lightning"
Miller Bobcat 225 NT (what I began my present Biz with!)
Miller 30-A Spoolgun
Miller Spectrum 300
Miller 225 Thunderbolt (my first machine bought new 1980)
Miller Digital Elite Titanium 9400