Stainless tube

[pro mod steve]

Done with school. Starting my first project. I have a set of stainless turbo headers to build anyone have any tips on back purging? Dos dont's tips on cheap tube adapters for sealing and introducing the gas for back purge.

[nocheepgas]

You can buy some relatively inexpensive, but there's no need to unless you just want a new toy. Tape some cardboard over an end, punch a hole in it for your argon hose to enter, put another piece on the opposite end with a small purge hole in it and weld away.

[hockeyguynick]

I've never used anything fancy, either. I do sometimes tape an old clear lens on one end so I can look inside and check for penetration w/o peeling the tape off all the time

[JonnyTIG]

Aluminum foil works well for capping tubes for purging, It conforms around the bends well. I also use aluminum tape quite often.

[Joe Porosity]

I love the clear lense idea! No more re-taping for me to check penetration!

Ur a genius hockey guy nick!

[Joe Porosity]

Stainless Steel Wool works good to!

I usaully tape out in the field, foil and steel wool can be easily lost inside a pipe.

Turn your main piece of tape sticky side out,then add a few small strips to hold it. Else you'll have a mad fitter cleaning off glue.

[rezsst]

cool something i always wanted to do. can you post some pics

[kelzweld]

Bring your purge hose in the bottom and vent out the top. I purge with about 5 or 6 litres /minute on the flowmetre. Guessing yours reads in cubic feet/hour???, but anyway, if you have too much gas inside, it'll push your weld out, and even if not too that extent, you just use more gas than you need too.

[Showdog75]

Bring your purge hose in the bottom and vent out the top. I purge with about 5 or 6 litres /minute on the flowmetre. Guessing yours reads in cubic feet/hour???, but anyway, if you have too much gas inside, it'll push your weld out, and even if not too that extent, you just use more gas than you need too.

I do the opposite , purge top vent bottom. Argon is heavier than air.

[kelzweld]

I do the opposite , purge top vent bottom. Argon is heavier than air.

I've never tried it that way. Was taught many years ago to do it my way, and the welds comply with NZ dairy industry standards, so thats the way I do it. If you follow this link, on page 1, the paragraph titled 'purging procedure' lists the same reason as I was taught. I'm not saying your way doesn't work, just that myself, and many others were taught to do the opposite.

http://files.aws.org/wj/2006/12/wj200612/wj1206-38.pdf

[JonnyTIG]

The Idea of the purge is to remove the oxygen completely from the atmosphere. I was taught that purging from the bottom slowly fills the part with argon from the lowest point, forcing all the oxygen out the top or vent. Reversing the purge allows the argon to fall from the top through the air inside the component, causing it to mix with the oxygen, creating a contaminating environment, but eventually becoming pure argon. Both systems work, however purging from the bottom removes the contaminants faster. Sometimes there is no choice which way to do it, depending on the access to the joint, fixtures and what not.