for those TIG pipe welders that use a 5/32 or 3/16 gap

By Tyler1970 (***)

Date 02-11-2010 15:34

on 5/32 gap tig. bout 100 amps
3/16 gap tig. bout 85-90 amps. 1/8 wire on both

By Cumminsguy71 (*****)

Date 02-12-2010 15:20

I might have to try a bit larger gap on what I'm doing by reading your post. 2-3" sch. 40 running 3/32 tungsten/filler, knife edge and less than the width of the filler is what I have been setting my gap at. Have to really push it in there but can get it in. I might have to open that gap up a bit and try.

By Iron Head 49 (***)

Date 02-11-2010 20:24

Just a structural hand, LOL! But I use 7/64-inch gap, (will close up to 3/32 inch) with 1/8th inch filler. Knife-edge, 75-amps for schedule 40, 100-amps for schedule 80.

By Blaster (***)

Date 02-12-2010 16:36

Iron Head I am with you - I have a strong preference for 7/64".

I am curious, assuming a choice, why would you use a 5/32 or 3/16 inch gap w/ 1/8" rod on 6" sch 40?

By gto_welder (*)

Date 02-12-2010 23:31

5/32 or 3/16 gap is just the way i was taught..... i was just asking what amps other welders used to put the root in with this gap because i see may other welder use the same gap and run their root pass a lot hotter, around 130 amps. i myself run my root pass with 3/16 gap, feather edge at about 95 amp on a 6" sch 40

By Blaster (***)

Date 02-12-2010 23:41

Cool - so what technique do you use to feed the rod into the puddle? Dip? Lean off parallel to the joint so it won't pop through the opening? Or?

By gto_welder (*)

Date 02-12-2010 23:47

i just lay the wire between my pointer finger and middle finger and feed it with my thumb. for the root pass i freehand the bottom and look through the gap to make sure i break the wall and once im halfway up i walk the cup for the rest unless of course it is in a tight spot and i have no other choice of to free hand the entire root.... the wire is always inside the pipe

By Tyler1970 (***)

Date 02-13-2010 01:20

gto did u ask ur wife to marry you with that wedding band? looks good

By gto_welder (*)

Date 02-13-2010 01:28

:D thanks man!!!

By Iron Head 49 (***)

Date 02-13-2010 02:11

See now I’m a little confused. Anybody who can do a root like that should be giving advise not asking for it!
Great job gto_welder!

By gto_welder (*)

Date 02-13-2010 02:20

i am a combination pipe welder ....i was just wondering what other welders who use the same pipe prep and fitup that i use run their root pass at... i just used a 6" sch 40 as an example.......... BTW your root pass looks pretty good also, it looks like you burned your edges

By Iron Head 49 (***)

Date 02-13-2010 02:49

“it looks like you burned your edges”
Is that good or bad?

I’m more in the hit and miss situation. I’m not near as consistent as I’d like to be.
Question for you, does your root have a little too much penetration? Seems as I’ve read 1/32nd to 1/16th, bottom line I guess it would depend on the code. Just can’t get a straight answer from anyone, any advice you’re willing to share?

By gto_welder (*)

Date 02-13-2010 16:18

burning your edges is a good thing.... if you dont burn your edge and they shoot xrays on it, they will get you for lack of fusion. as for too much penetration, i guess that depends on the code.....everywhere that i have worked, the QC just says to keep it under 1/8.... in that pic it looks thicker than it really is. the penetration in that pic is under 1/8

By Iron Head 49 (***)

Date 02-13-2010 16:55

Thanks for the information!

Funny how a camera distorts things, I kind of figured your root was a little smaller than the pictures shows.

By Jim Hughes (***)

Date 02-12-2010 22:32

I love it.!! Works great on stainless also. Especially SCH 10 with 3/32" wire. You learn to use a bigger gap and bridge it you will throw rocks at anything else.

Jim