: if you want a bombproof bond do the sanding etc but cut a groove in the
: insert and one in the mast so that once together they will be in the same
: position, when its epoxied the epoxy ring formed in the groove will keep
: the insert in even if no other bond happened.

That's a little scary for me. However I have found that the thin Diabloe circular blade that some of us use to cut wood strips also cuts really good on aluminum. I have cut 1/4 inch thick aluminum with no problems. But wear goggles.

Another way of locking the tubing together would be to make a round piece of soft wood that would slide into the smaller tube for support, maybe an inch long, then take a center punch and punch the walls of the tube into one another in a few places locking the tubes together, then drive the soft wood out of the tube. The aluminum tubing would be driven part way into the soft wood but the wood could be pushed out of the tubing. The wood would also keep the tubing supported and round while center punching it. I like this idea but I can't do it now since I have the smaller tubes filled with foam. The epoxy idea should be fine I think.

John