WeldingWeb - Welding Community for pros and enthusiasts banner
Cancel
Create thread New Forums

Tungsten Tip keeps going crusty and green

Jump to Latest
5.7K views 20 replies 13 participants last post by  mcostello  
D
#1 ·
I'm running out of things to check here but this is getting really frustrating. I'm by no means new to welding and have been welding for years now, but can't seem to figure out this issue with my machine today.

Was welding fine with it all morning and now this evening, the back cap threads were starting to get gummy and wouldn't hold the tungsten so changed back cap, then went to try and weld again and been trying to trouble shoot this for a couple hours now. This is what I'm getting, tip discoloring to green and going crusty at the end. Which results in black soot and makes the weld look like it lacking gas.

http://s10.postimg.org/gp837dl3t/IMG_20151218_211711.jpg

Things I've tried:

Change back cap
Change torch body
Change collet and holder
Change tungsten
Changed different diameter tungsten
Changed gas cups
Checked for gas leaks
Gas set to 15cfm but tried up to 25 cfm

All with no real things stopping it from doing it. Sometimes it does it instantly after I sharpen the tungsten, other times, I have to weld for a couple minutes than it starts doing it.

Its really aggravating me right now, trying to finish a job for tomorrow. .. Any help is greatly appreciated!!
 
S
#2 ·
Barely crack the backcap leaving it in place. Pull the front end parts out and look inside to see if the backcap is choking off the gas hole. If not, replace the front end and pull the backcap off and see if the collet body is choking off the gas hole. Also check the collet to see if it is choking off the gas. How about the backcap? does it have a crack or hole in it?

Lastly I would confirm the gas flow with a portable flowmeter. I get mine at www.netwelding.com

Image
 
Save
Reply Quote Like Like
J
#7 · (Edited)
shovelon said:
.

Lastly I would confirm the gas flow with a portable flowmeter. I get mine at www.netwelding.com
Click to expand...
Interesting website (netwelding) but a bit a bit confusing... reminds me of an infomercial ...
I see the flow meter sales pitch, but no purchase info...
What did you pay for that?

Did you also purchase the gas saving hose?


I found a similar tester on arc-zone .... https://www.arc-zone.com/index.php?main_page=product_info&cPath=437_1485&products_id=7909

also here for less:
http://weldingdirect.com/gasflowchecker.html

This looks like the one netwelding sells...
CK...
http://weldfabulous.com/ck-ck-gft-gas-flow-tester/
 
Save
Reply Quote Like Like
D
#3 ·
Shovelon,

I don't think its obstructed in anyway, I can hear the gas coming out at pretty much the regular rate that I'm used to hearing it (I tig weld pretty much everyday so know the sound)
But even if it was obstructed a bit, increasing the CFM should of solved it and would do it all the time pretty much instantly especially since what I'm welding i'm around the 160ish amps.

This is a far shot, but realized that the one back cap was slightly oily on the inside, tried cleaning it up with acetone right, but still didn't seem to help, grabbed another new back cap and still doing the same though now. What are the odds that maybe now I have a light film of oil on everything ?!?!?! crazy far strech idea, but would make the most sense to me right now .. Not sure if Everything can be cleaned 100% to remove any contaminations.
 
S
#4 ·
Is it an aircooled torch? I came across one that had a greasy power cable that spewed smoke onto the weld and crusted the tungsten.
 
Save
Reply Quote Like Like
W
#6 ·
Could your parent metal be dirty or wet? Any moisture will flash when hit with arc and give off oxygen, contaminating the puddle and tungsten.
 
Save
Reply Quote Like Like
S
#10 ·
The one you got is graduated in liters, and has the rubber on the outside?
 
Save
Reply Quote Like Like
W
#11 ·
did you change tungsten recently maybe bad tungsten ?
did you change argon recently maybe bad argon or you got a 75/25co2 mix by mistake ??
you could have leak or hole in hose somewhere replace hose with short good condition argon hose ??
you metal you are welding can be contaminating things giving off fumes? i have had old parts give off stuff cause problems before
your filler metal wire can be giving a problem contaminating things ?
 
W
#14 ·
.
yes the most common size air cooled tig torch is usually rated 100 amps and doing aluminum at over 200 amps with one will overheat it pretty fast. i had a extra big air cooled tig torch rated 150 amps and i could do short bursts of aluminum welding at 250 amps but anything more than a minute or 2 and even that torch would easily get too hot to handle
.
you can easily damage a air cooled tig torch it you are welding at too high a amps
 
T
#17 ·
Did you try flexing a non-flex torch?

I know it sounds like a stupid question, but we had a guy at school who somehow got a non-flex one and wondered why it stopped working.
 
Save
Reply Quote Like Like
D
#19 ·
Delayed message but still better than never. The issue was oil in the hose. I guess one of my genius guys thought spraying on penetrating oil on the back cap threads was a great idea instead of changing the torch head or back cap as the threads were feeling tighter. So the oil for everywhere and couldn't clean it up good enough in anyway so had to toss that hose, backcaps that git contaminated, along with torch head and and ceramic cups.... Was not impressed to say the least.
 
WeldingWeb - Welding Community for pros and enthusiasts
posts
1.8M
members
82K
Since
2003
Community Forum for Welding Professionals and Enthusiasts To Interact and Learn - Free
Full Forum Listing
Explore Our Forums
Welding Projects & Pictures General Welding Questions MIG, TIG, Stick, And Oxy/Fuel Welding Machines - Tools and Cutting Methods Lincoln