I was watching "A 4x4 is born" this morning and the fella was making a darn good looking job of mig welding the rollcage using large overlapping weld spots.

So whats the best technique for welding rollcage tube, Tig welding aside.

Have u done much round tube welding or Mainly loads of box section?
Shug

i always seem to miss '4x4 is born' when its on

haven't done any rollcage welding yet, hence the question

@Joel

it was on discovery this morning



[Edited on 1/1/09 by liam.mccaffrey]

I always found that welding round tubes very hard - keeping the distance, angle and tracking right is hard enough on square section, but when you add having to move the torch around a curve as well...

i use a similar tecnique for welding roll cages into rally cars its not so much spot welds more a case of momentarily releasing the trigger during the weld run to keep the weld bead as small and tidy as possible it also helps to maintain penetration without building up to much heat around the weld as this can alter the strengh of the high tensile T45 tube used in a modern multipoint cage. m.

quote:

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Originally posted by MkII
i use a similar tecnique for welding roll cages into rally cars its not so much spot welds more a case of momentarily releasing the trigger during the weld run to keep the weld bead as small and tidy as possible it also helps to maintain penetration without building up to much heat around the weld as this can alter the strengh of the high tensile T45 tube used in a modern multipoint cage. m.

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Do try this at home. I need to get some excercise before I weld my roll-bar on.

Reading the above posts, I am wondering if I would be able to keep the welds tidy.

Secondly, it's hard for me to imagine this technique gives sufficient penetration, as welding in one go puts more heat into the welding area.

How do you make sure you have enough penetration all the way? By making some samples and cut them open?

I tend to position weld quarter of the tube at a time, tack top, bottom left and right sides, then follow through by stiching the top,... bottom,... left... and right by segments. I also tend to slow the wire speed down a bit, and forward weld to get better penetration. I have however changed to Tig more often than not for all our tube welding.
Shug