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Up Topic Welding Industry / Welding Fundamentals / trying to pass a 6g tig test
- - By chrisodom980 (*) Date 12-28-2007 20:19
I m tring to pass a 6g tig test. i have to tig the root and hotpass and stick out. i m putting a 3/32 gap and when i tack it up it does fine but when i weld it in postion it dosent have enough penatration any info would be helpful. I also have to do the same thing with 2 inch carbon with 309 wire.
Parent - - By MBlaha (***) Date 12-29-2007 05:19 Edited 12-29-2007 05:24
Hmmmmm. Lets see if we can get you up and running. OK, what size filler wire are you using?  I myself, prefer to set the gap slightly less than the filler wire diameter. Are you holding your tungsten at as much of a 90 degree angle as you possibly can? I have found that the more perpindicular you run your tungsten, the more you drive your filler wire into the joint giving you that desired wedding band effect. I have seen welders use different methods of adding their filler metal. Some like to open up a key hole, and then  push the wire in and let the keyhole fill up. Myself, I prefer when I can, (which is almost 99.9% of the time, to bend the wire to reflect the inner diameter of the pipe or tube, and just lay it in the root opening, and run the tungsten right on the wire, with a slight up down motion just a little less than the width of the wire, moving as fast as I can, still making sure to fuse both the top and bottom edges of the root. What type of root bevel preparation are you dealing with? We always make sure that we are welding with what we call a knife edge, no land what so ever. What size tungsten are you using? Most times, I try to use the same size tungsten as the filler wire. Do you have a nice sharp needle point with the grinding lines, (unless using already processed, polished tungsten) running in a spiral down to the point, and then flatten just the very tip so that when you look at the point, you see just a very small flat spot on the tungsten. Make sure your tungsten is clean. Any contamination will cause your arc to wander off to the side of your tungsten, rather than coming right off the point, and thus you are loosing control of you arc Try to think of the arc coming off the tip of your tungsten as a driving force. (driving the filler metal into the root. What is your heat setting? Might be you are not hot enough. It could also be that you are traveling too fast. I guess we need some more information so that we can help you. My email is in my profile if you wish to contact me. If you wish, I will give you my phone # and we could discuss this. I guess I have alot of questions for you, but there are so many variables that can affect your penetration.

My 1.5 cents worth.

Mike
Parent - - By dbigkahunna (****) Date 12-29-2007 16:29
If it is IP then you do not have enough gap. I agree, the gap should be slightly larger than the filler wire.
BABRT's
Parent - - By chrisodom980 (*) Date 12-29-2007 17:04 Edited 12-29-2007 23:06
The gap is 3/32 to 1/8 thats what i have been setting it to. if i am using a 3/32 wire i set my heat to 75 to 80 amps if i use 1/8 wire i set my heat to 90 to 100 amps on carbon. i have weldied a couple of cupons and some of them look pretty good but som look very sh***. i have tried different things every time. but nothing consistant. also i am using a 1/8 tugsten with no gas lens on carbon, but i do use a gas lens with stainless 309 on carbon and purge.
Parent - - By dbigkahunna (****) Date 12-29-2007 23:37
If you have pleanty of gap the next thing would be the landing. If you are using a feather landing, over 3/32 gap and still have penetration issues, then it is your heat.
Parent - - By kubotaboy Date 01-03-2008 23:58
are your tack large enough so that when you start rooting the gap doesn't closes up and prevents 100% penetration? I do good strong tacks, no landing, strong keyhole, drive that filler  
wire in, or you will get "suck back".
Parent - - By js55 (*****) Date 01-04-2008 18:22
Running a gap wider than the filler helps to see your penetrationbetter but it requires a little more skill.
One thing thatmight help, as you run over your wire visualize where the edge of your pipe is and hesitate a bit, pointing your tungsten right at the edge(the arc is hottest right under the tungsten), to make sure it consumes. If you've ever watched the puddle from the inside you can see it swirl. You want that swirl moving right over the top of your edge. If its feathered you don't need to hold as long. If it has a landing I always thought it helpful to push on the puddle slightly with the wire to help prevent concavity, or as mentioned tilt the wire up. I used to tilt the wire stright up when tying into unground tacks and oscilllating a little wider.
Parent - - By pypLynr (***) Date 01-20-2008 00:53
hey chris, I gap @ 1/8 to 5/32 and use a 1/8 filler on carbon.And I use a tight 1/8 with 3/32 filler on s/s sch.10 .  My tacs are bridge style in the four quads. you are 'bout right on your heat on both.Now on tie in of the tacs slow down a bit and push your filler a tad more.If you use bridge style you just grind 'em out and keep goin'. js55 is got the right idea on visualizing your pipe edge. ya know ALOT of the technique comes from just burnin' coupons and rods. PRACTICE ! Good luck on your test.
Parent - - By chrisodom980 (*) Date 01-20-2008 13:07
thank yall for your advice I think i passed they called me to go to work.
Parent - By pypLynr (***) Date 01-20-2008 21:58
Congrats! and good luck!
Up Topic Welding Industry / Welding Fundamentals / trying to pass a 6g tig test

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