First you will need some hose, here is mine all assembled:



This is the input end, you can do it differently than I have, but these were the fittings that i had available and they seem to work well. You NEED a ball valve (for turning your back purge on and off) and the other valve is a needle valve to adjust the amount of flow coming out of the hose. I just adjust it by listening to it.



Here is a T you will need to add to your bottle regulator. Again, I used these particular fittings because that was what was available at the time. I wanted to make mine removable as well so I added a high end quick disconnect that is designed to prevent any types of leak.



Here is the hose connected:



Next, gap your pipe slightly so that you have room to add filler when welding your joint. Some people like to take a piece of filler and bend it into a "V" and stick it inbetween the two pipes for setting a nice even gap and then pulling it out after tacking. For this example i used 1.75" .083" wall 304ss piping. Tack it together so it will not move on you once you start welding.



Once you have it tacked together cap both ends with some cap plugs. These fit like a glove and are much nicer and cleaner to use than tape. They also withstand a bit of heat as long as you don't get to close with your torch. Add a hole into one of the cap plugs that the tube/hose will fit snug into so as to prevent argon from leaking back out the hole you made.



When you get close to the end of welding your joint you will need to slip the end plug slightly off the pipe to let the argon escape or it will try to exit through your joint and that makes for difficult welding.



I just did a single pass on this at 70 amps but with thicker base metal you can do multiple passes with purging only being nescassary on the first pass as long as you don't blow through it. The inside should look something similar to the pic below. Once you get really good, the inside should look just as good as the outside... I'm not there yet.

 

preventing redox ftw, nice.

 

Great post Aaron! Just working with my fluxcore and never dealt with backpurging and never ran gas. Now I have my TIG this will be very helpful and quite informative. This deserves some sticky icky action.

 

best way is to shove a slice of bread into the pipe near where you're welding. Don't bother capping the ---- off with real caps. Waste of time.
Argon is also heavier than air, keep that in mind when working in confined spaces & when backfilling.


& if you get your gas coverage down close to where you're welding. It takes very little flow. 5cfm.

 

Aaron, you're a pimp. I don't care what they say about Canadians.

 

sticky this sucker BD

 

Get off Aarons nuts Steve, he doesnt need you to tell him his work is an inspiration to all

 

thanks for the thread.

on a side note, do you guys know of any great tutorials, beginner's guides, tips&tricks to tig welding? i don't know much about it (for example, up until now i had no idea what back purging meant lol)

thanks i'd really appreciate it!

-Luke

 

these will keep you busy reading for a while:

http://millerwelds.com/education/library.html
http://www.lincolnelectric.com...st.asp

 

thanks! read through most of it already. Good stuff, learned some important things to try next time around.

Any links on tube welding? like techniques for clamping pipe together so you can tack weld

thanks again, sorry to side track your thread btw. I'd take it to pm's but others may gain from it aswell

-Luke