[oldslow]

Anyone here have a video of someone running blind tig on pipe?

[weldin mike 27]

Hi there,

Is that welding with a mirror?

Mick

[oldslow]

I'm not even sure. I was told that you weld with the wire thru the pipe where you can't actually see your torch/tungsten. So basically the tungsten is pointed up toward you while you slide the wire thru the pipe to it...if that makes sense. I'd like to see it and I'd like to know why one would weld that way...

[weldin mike 27]

Hi there,

Now im with ya. I have seen this trick in videos and things. They tried to teach us to do it on our pipe cert but we found a better way. I beleive it is a way to get nice clean metal on your root pass, whilst eliminating suck back or root concavity of the molten metal.

It sounds like a very diifficult technique to master, with limited practical uses. There are easier ways to do root runs. Jody has videos of these in the main menu of this site.

Hope this helps
Mick

[rahtreelimbs]

I have very limited time TIG welding. At my last job I started to get the hang of "walking the cup." One of my coworkers was doing the technique that you describe. I tried and it takes a lot of technique..........never did find out the reason for using this method.

[Otto Nobedder]

I've heard this called "backfeeding", and I've had to do it before. The circumstance was that the joint was so close to a vessel and surrounded by loads of other things that were impractical to move, so getting both a mirror and a torch into the space was impossible. So, the hidden section was done first, with the back-feed method, then inspected with a mirror. Capping this section was done completely blind, by feel alone, which often resulted in crap. But once the metal was laid down, I could wash over it as often as it took to get the cap tied in sufficiently. Yes, backfeeding is difficult. I had to sharpen a lot of tungsten when that weld would come up.

Steve