Butt or mitered corners for 2x2 box perimeter

[frank_a]

I've built a number of frames over the years, and always do butt joints. I've made plugs to weld solid tube ends as well as removable inserts so wiring can be run, or bulbs replaced or whatever.

Frank

[NathanL]

Structural steel fab shop owner and detailer. We almost always use a butt joint instead of a miter just for the sake of speed, and that includes pretty much everything we do from a simple frame to work inside a chem plant/refinery. If it's an angle we'll cope it to fit the other angle 99% of the time rather than miter.

The only reason to miter on a trailer or something similar is you want to close off the end of the tube for appearance or to keep wasp next etc... out of the tube, which may be enough if you live in an area with lots of them.

[cracker39]

I used my Craftsman chop saw to miter cut the 11 ga tubular steel for the Squidget's frame. It didn't seem cause any damage to the saw, but I did have to take the saw off the stand to get the grit and crap cleaned out. This time, I've made a 2 piece shield of aluminum flashing to put in place of the plastic slot where the blade cuts through. I just hope the hot grit doesn't burn through the shielding, which it probably will.

The chop saw made perfect mitered corners that welded great. I also made my straight cuts with it up to 7 ga., cutting slowly and not putting pressure on the blade. For the long angular cuts on the front of the A frame tongue, I used my grinder with a cutting disk.

I bevel the cut edges on the miters to make a V depression for the weld bead so it can be ground nearly flat on top without destroying the weld itself. I don't grind off the bottom weld beads as they aren't seen.