Welding Tips and Tricks

Hello
Having great difficulty putting in tig root pass in 4 inch schudule 40 pipe. Can you offer any tips Thanks

What is the thickness and joint preparation, amps etc that you have been using?

Do you know how to walk the cup on an open root?

.what is the root opening?
.are you starting at a tack?
.amperage?.
.
.
.the size of the pipe really doesn't matter, unless there is a breeze blowing through it.
.thickness?
.bevel?
.stickout?

here's how i do it.

first of all i would just like to mention that i weld with the workpiece in a vertical position, turning it around with a rotary table.

- first of all i make sure that the bevel nose is ~0, this makes for easier penetration.
- then i clean of all the parts using acetone or something simular.
- i tack the pieces together with a 3.2mm root opening. i just use a 3.2mm fillerwire.
- with the piece tacked up i place it on a plate with a little hole in the center, then i place my purge ontop.
- when it comes to amps, i would use something like 75 for stainless and maybe 90-100 for mild steel.
- fillerwire would be 2.4mm
- most of my heat is directed on the top part while i feed wire also at the top. i then drag it down to the bottom part.
- when i've completed the full 360 degrees i overlap about 10-15mm just to eliminate any lack of penetration.

speen wrote:here's how i do it.

first of all i would just like to mention that i weld with the workpiece in a vertical position, turning it around with a rotary table.

- first of all i make sure that the bevel nose is ~0, this makes for easier penetration.
- then i clean of all the parts using acetone or something simular.
- i tack the pieces together with a 3.2mm root opening. i just use a 3.2mm fillerwire.
- with the piece tacked up i place it on a plate with a little hole in the center, then i place my purge ontop.
- when it comes to amps, i would use something like 75 for stainless and maybe 90-100 for mild steel.
- fillerwire would be 2.4mm
- most of my heat is directed on the top part while i feed wire also at the top. i then drag it down to the bottom part.
- when i've completed the full 360 degrees i overlap about 10-15mm just to eliminate any lack of penetration.

Man ! i could have fun welding beside you.