Does anyone know if its practical/recommended to butt weld round tube end to end. Seems pretty ok to me, but just wanted to make sure!

Best to use an insert if you weld anything end to end.

yours, Pete.

. . . with holes drilled in the outer tubes so you can also fill in rosettes an inch or two above and below the joint.

Petef,

Does this apply to RHS as well? Is it advisable to use inserts or is it ok to butt well end to end for RHS? No u got me wondering...

with ref. tube, I have read that it's also a good idea to cut the tubes at an angle, or cut two angles (a vee shape) so the weld is longer and stronger. That was for welding a smaller tube into a larger one, would think it applies though.

I think that aircraft practice (and Carol Smith's books suggest a sleeve over the OD of the tubes, and a scarf jount of V cut on the end of the sleeve. IIRC, you weld each of the tubes to the sleeve, and do not weld them to each other