Thanks: 0
Likes: 0
Needs Pictures: 0
Picture(s) thanks: 0
Results 1 to 10 of 10
Thread: Dull Grey TIG Welds
-
10th November 2011, 05:49 PM #1Intermediate Member
- Join Date
- Oct 2011
- Location
- Newcastle, NSW
- Posts
- 34
Dull Grey TIG Welds
I am learning to tig weld at the moment and only had a few hours at the bench on some stainless, aluminium and mild. I am concerntration on mild steel at the moment and just spent an hour or so welding some beads on 3mm thick mild sheet which I ground all of the rust etc off before starting.
All of the welds are turning out a dull grey matt colour. If I hold the torch in position for the post flow which is around 10-12seconds the final part of the bead will say shiney but if I move the torch even near the end of the post flow you can see it quickly change to the dull finish.
I am welding on DC and tried a few differant amps from about 70-130 but using the foot pedal as well - usually giving it flat out to start then backing off a bit.
Gas Flow is 10L/min and I also tried up to 15-18L/min
Tungsten is 1.6mm Red (Thoriated)
Filler Rod is 1.6mm ER70S6
I am also welding inside my garage and did move the welder a meter or so away fromt eh bench as I thought the cooling fans may be blowing the sheilding gas away.
I am also pretty sure that their arn't any leaks in the gas line from the bottle to the gas solinoid as I turn my bottle off when I am finished welding and I can come back the next day and the pressure guage will have only dropped very slightly.
Any ideas on why I can't get a full shiney bead?
Any help much appreciated
James
-
10th November 2011 05:49 PM # ADSGoogle Adsense Advertisement
- Join Date
- Always
- Location
- Advertising world
- Posts
- Many
-
10th November 2011, 05:52 PM #2Intermediate Member
- Join Date
- Oct 2011
- Location
- Newcastle, NSW
- Posts
- 34
also forgot to add that stickout is about 3-4mm and I tried using a no 7 and a no 5 cup
Thanks
James
-
10th November 2011, 06:59 PM #3SENIOR MEMBER
- Join Date
- Feb 2010
- Location
- Ballina, NSW
- Posts
- 725
Your gas flow is too high and is probably mixing air into the shielding: 10 LPM is the most you should use with a 7 or 8 cup. Also - are all the welds are like this? Often they will get as you describe when the gets too hot after welding successive beads in a row. Cheers - Mick
-
10th November 2011, 07:25 PM #4Intermediate Member
- Join Date
- Oct 2011
- Location
- Newcastle, NSW
- Posts
- 34
All of the welds seem to turn out like this, even the first few. I will try turning the flow down slightly then and see if that makes a differance.
Any other suggestions
Cheers
James
-
10th November 2011, 08:13 PM #5Member
- Join Date
- May 2008
- Location
- Sydney
- Posts
- 77
Hi James,
Is the collet in the correct way around with the split end (the slits) pointig toward the tip of the tungsten? If in back to front the shoulder can reduce the gas flow rate by creating a restriction. Are you traveling into the welding zone or are you pulling away from it?
From your description it sounds like a gas related issue in that keeping the material shielded prevents oxidisation whilst it is still hot.
Cheers
Pete
-
10th November 2011, 11:25 PM #6
Gidday
Ive gotten great results using 10-14 on the gas for my money your stickout is way to much get the arc as close as you can to your weld pool!
I never use a 3-4mm stickout I try to stay around 1mm n am virtually touching it when walking the cup!
You'll get much less shake rattle n roll By developing a good comfortable grip and looking for any way you can prop your wrists torch hand etc etc.............
Practice walking the cup for those shinny beads your chasing. If you can master this technique you'll consistently get great looking welds in most positions!
Regards LouJust Do The Best You Can With What You HAve At The Time
-
11th November 2011, 08:31 AM #7Intermediate Member
- Join Date
- Oct 2011
- Location
- Newcastle, NSW
- Posts
- 34
All taken onboard - will have another crack this arvo.
I am pretty sure the collet is in the right way but will double check - I didn't think it would tighten up on the tungsten if it was in @rse about)
I will try a shorter stickout but from what I have read 2 or so times the diameter of the electrode should be fine - it is set so I can just see the tip of the electrode without having to lay my head on the bench. I set the cup on the test piece (3mm) and then tightened up the electrode when it was touching the bench - figured it would be a way of keeping a constant stickout when I have to keep changing electrodes
I have the test peice set up so that the thick cuff of the tig glove is resting on the corner of the bench - mid forarm. I find unless I have had too many cuppa's I can hold it fairly steady.
I am still working on correct arc lenght and getting consistant but I must be sitting fairly close as I have to change quite a few electrodes cause I have stuck it to the plate ot sucked up metal out of the weld pool.
I am welding into the welding zone - pushing the puddle and tapping the filler on the front edge of the weld pool.
Gut feeling make me think I am getting too much heat somehow or not a tight enough arc causing the weld bead to take too long to cool.
Hope to get a bit more time this arvo practicing
Cheers
James
-
11th November 2011, 08:32 AM #8Intermediate Member
- Join Date
- Oct 2011
- Location
- Newcastle, NSW
- Posts
- 34
Not sure if it means anything but the welds shine up ok with a quick going over with the wire brush
-
11th November 2011, 10:05 PM #9
ID also recommend checking out Jodys Welding Tips and Tricks u tube channel..................all the basics are covered and im sure you'll gain a lot of information that will improve your technique n may address your issue.
Webpage: Welding Tips and Tricks - TIG, MIG, Stick and a pantload of other info
U-Tube: weldingtipsandtricks's Channel - YouTube
Regards LouJust Do The Best You Can With What You HAve At The Time
-
12th November 2011, 09:58 AM #10Senior Member
- Join Date
- Apr 2011
- Location
- Brisbane
- Posts
- 116
had the same problem with my stainless welds on a little stick/tig inverter i bought. was mostly due to too many amps, but i also found going to a #8 cup helped as well.
how much push angle are you giving it also, doesn't need too much maybe 10-15 degrees
Similar Threads
-
How many welds?
By Single-phase in forum WELDINGReplies: 7Last Post: 24th October 2009, 04:23 PM -
'dull off'?
By 44Ronin in forum WOODTURNING - PEN TURNINGReplies: 2Last Post: 20th March 2009, 07:47 AM -
Dull patches in padded shellac finish
By silentC in forum FINISHINGReplies: 12Last Post: 15th November 2008, 10:14 PM -
things seem a little dull
By astrid in forum NOTHING AT ALL TO DO WITH WOODWORKReplies: 47Last Post: 23rd November 2007, 09:53 PM