Purging Stainless Box Section?

[adri123]

Hi

New to TIG so a newbie question.

When welding 30mm box section stainless into 90 degree corners (ie 2 x 45 degree cuts joined) should I set up a purge pipe?

TIA

Adri

 

[oilcooled :)]

Depends on the spec normally no for a handrail cause you will b putting as little heat into the weld as possible to minimize distortion. However if your looking for a root /full penetration weld and a no coke on the inside of the box a purge would b a good idea

 

[Richard.]

If there is any chance your going to punch through and you cannot get onto the backside with a tight backing then yes you should be purging on the inside. Sugaring/coking on the inside is a bad thing and will almost certainly compromise the weld. Lots of people don't bother but in my veiw if I start a job I start it to do it right