problem of welding being affected by gravity

[rajit]

we are using a jig-fixture set up to keep all our pipes in place. there is one problem though . the underside of a lot of pipes(mainly base pipes) are difficult to weld because of lesser area to move the torch around. also the bead starts falling because of gravity leading to more weld gaps and pipe burns and discontinuous welding.

please suggest a solution to avoid this problem...

[rajit]

we are using a jig-fixture set up to keep all our pipes in place. there is one problem though . the underside of a lot of pipes(mainly base pipes) are difficult to weld because of lesser area to move the torch around. also the bead starts falling because of gravity leading to more weld gaps and pipe burns and discontinuous welding.

please suggest a solution to avoid this problem...

[oz_olly]

You could always turn your jig upside down. Many race car chassis builders have a 'car on a spit' type jig that allows them easier access for welding. You could also place heaps of tacks all over your chassis (four or five tacks per joint) and then take it out of the jig while you get to some of the harder welds and put it back in the finish it off and check you haven't warped things too much. If your chassis design is such that it requires really tight tolerances then you probably aren't doing it right. There are only a few points on a chassis that really have to be accurately located and that's normally in relation to each other.

Cheers

Olly

[Lutter]

Can you weld the frame everywhere but the bottom of the tubes, then pull it off, flip it upside down and finish welding? I would highly doubt that anything would twist from welding a little bit especially after its mostly welded already.

[vandit]

@ Rajit,

I saw teams who have their jig-fixture bed elevated from base. But for our limitations, i think what 'Lutter' suggested should work.

Regarding that bead flow, i always thought that's not normal. Try finding more info on this point.

[BillCobb]

There's some extra space on the Space Shuttles in the nex few missions. That can get you a gravity-lite environment...

Is this a TIG weldment? Gravity should not be a factor.

[Mike Cook]

I agree, I never have seen gravity effect tig welds much. If I'm mig welding, usually I will stich weld where you weld on for a seconds, then off for a second. This keeps the heat down, and keeps the weld from running out.