[Schmitty]

Hello guys and this is a first post for me.

I have little experience welding pipe and am trying to practice to hopefully open new doors for my carrer. I have been practicing on 2 inch stainless pipe in 6g and I can get my root and hot pass in there decent but im having a hard time with the cap. Really, its kickin my butt. I let the pipe cool completly between passes and keep the purge running during each pass. It seems im getting the cap too hot as its turning gray and im getting undercut. I figure i also must be going way too slow. im using a 1/8 gap feathered edge running everything at roughly 75 amps using laywire. Im am not walking the cup it it matters. I was wondering if the more experienced people had some tips, or if there was a video out there of somebody doing a tig cap that i could watch cause im very much a visual learner. Thanks a lot in advance.

[Arizona SA200]

Flowmeter or regulator? What cfh? Do you change the torch angle for the cap? Do you have good color in the previous passes?

[Arizona SA200]

Forgot one. How thick is the pipe?

[Schmitty]

I run about 20 cfh and i try to keep the torch angle kinda up and down, but due to inexperience and the fact that how i have it set up, its hard for me to keep a constant angle on the torch ( not paying attention). When im starting from the bottom, im literally crouched down. Its scrap pipe from work that i believe is schedule 40. My cup opening is roughly 3/8" but to be honest im not sure on that. Ill check that when i get to work monday. I get decent color on root and fill. Nothing like the bad color on my cap. I feel like such a newb after re-reading this reply. I think its mainly i cant get comfortable and a combination of cup size and speed issue. My amps on cap pass using 1/8 rod run around 85.

[AKweldshop]

No foot-pedal I'm guessing?

[Schmitty]

I did have one but floored it and only used it to start the weld and then cover the weld in gas when i was done. Te bottom of the pipe was about two foot off the ground and it was hard for me to use it to control amps while kneeling. The pipe was set up in a turner. Like i said, im a complete newb to pipe welding.

[AKweldshop]

Stainless tig is harder than carbon for presetting amperage, (meaning you've gotta have your amps pretty close)
Practice Practice Practice....
Oh! one more thing, do you have a Tig Finger?

[Arizona SA200]

If you are looking to get in to the pipe trades learn to scratch start with no pedal. I think your amps may be a little high if it schd 40. Try running it down a little lower for the cap. This will be slower but more controlled. The range between plastic state to fluid state on stainless is a lot lower than carbon steel. I also have to ask why you aren't walking the cup? When I run a cap on stainless I like a #10 or #12 cup with a jumbo gas lens, but i walk it.

[Schmitty]

Thanks to all for the information. I was not walking the cup because i mainly want to be able to do it freehand, and that its almost more comfortable for me. I also have a bad habit of bearing down too hard when i walk, and slipping off the pipe. As for now, im gonna try to get the pipe in a more comfortable position and setting up for scratch start. Ill also try a big cup and try to walk it because im sure it will help me keep a more consistent torch angle.