rounded edge box section prep

[MartZ0r]

hey fellas. got a lil project on the go. i am making me some gym equipment for at home. i am making a squat/power rack out of 50 x 50 x 3mm rounded edge box section.

my question is considering i have rounded edge box section instead of cornered, would i be better to join the corners at 90 degrees (one ontop of other and put a piece in the end or mitre them at 45? either way i will gap it to 1mm to help with penetration. if i do the 90 corner and sit them ontop of each other, i will direct most of my heat to the rounded edge of the box section, obviously this is the hardest part to penetrate. i highlighted it as a black line on the attached pic i found on here.

im am thinking more so to the 90 corners myself. just looking for input.

 

[MartZ0r]

also forgot to ask what would be best weld technique for the runs to help with the penetration? i can penetrate it with just a straight run to be fair.

 

[rtbcomp]

This thread may be of interest

http://www.mig-welding.co.uk/forum/showthread.php?t=27742

 

[Hitch]

If you are butting them up, dont worry about leaving a gap. Welding joints like that in radiused box is quite nice, watch for undercut on the edges of the cut ends., if that makes sense...?

When you get to 300x300x16 box, then the radius is a pain.

If you mitre, leave a small gap, as you say.

 

[MartZ0r]

thanks fellas, i have had a look at the other thread, going to keep an eye on it. im gonna just butt joint it i think. doesnt seem that much of a difference other thean being easier to square up doing a mitre. Id say its easier to penetrate on a mitre joint so i will try a test on both types before i make my final choice.


its not nice to work with rounded box section of that size. i can imagine the huge gap you would have on the sides. nasty! i have run into that issue myself at work with larger sizes.