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G'day all,
I want to weld a hitch receiver to the end of my camp trailer and have the dilemma of having to weld 6mm 65x65 SHS to 45x45 what I think might be 45x45 1.6 mm wall.
I have a unimig 180 and have never had this challenge before.
Any advice on what would be the best was to heat enough to penetrate the thick stuff but not blow a hole in the thinner?
Thanks
Geoff
Keep the weld pool on the thicker metal then just dip the ark onto the thin stuff
Thanks Rat.... should add that it's also a overhead weld :C
Practice on scrap, and keep practicing.
I hate overhead welding, probably because I never do it. But as Aufitt suggested get some scrap and have a play around first
Turn the tailer upside down and the weld quality will improve enormously.
If you can't invert it try rolling it on one side.
There's nuthin like laying under some hot weld spatter:) even with a hood and weld jacket!!!
I'm with zuffen and tip it if you can practically achieve this in the shop.
Dont recon you could get the heat into the 6 mm as fast with a sml mig than whats possible with an arc. Well not in my experiences anyway. Will admit to preheating with the arc away from the weld area and quickly switching to mig and welding.
If the Hitch receiver on the rear of the Camper is for carrying a bike rack, my concern would be the 1.6mm material of the Camper chassis, not your welding.
Even if you went to the trouble of turning the Camper over and getting a good weld penetration by keeping the weld pool in the thicker material like Rat said, the weight and forces of three or four bikes on the end of a bike rack constantly bouncing along an Australian road are huge. It won't be the weld that gives way, but the 1.6mm steel around it.
I would look at putting another length of chassis rail across the rear in 3-4mm material, stitching it to the original and to the side rails. I would even go as far as two more short lengths running longitudinally from this new cross rail to the next cross rail forward to allow welding of the rear of the hitch receiver. This 'T' frame could even be fabricated separately so as to get good weld penetration before slotting it under the Camper and attaching to the chassis.