Welding Aluminum thin walled pipes (3mm) butt joint using TIG process

by Petes
(UAE, dubai)

I am welding aluminum pipe with wall thickness 3mm using TIg process but i do not get a good finish or a satisfactory weld in the root side. do i need to purge on the root.do i need to have a root gap for 3mm. what other preparation should i take.

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purge always helps.

but is not always a requirement .

one trick is to seal the joint with minimal heat and filler wire and to do a second pass where more amps are used to push penetration thru.