[TowerTalk] Fastening sections of 3" boom material

[Bill Turner]

I'm considering building a long yagi for 20 meters and I see the ARRL
antenna book recommends using 3" aluminum tubing for the boom. One
thing I don't find is how to connect the sections together. There
doesn't appear to be a standard tubing size which would slip either
inside or outside the 3" tubing to allow clamping or riveting. Or
maybe I just missed it.

Any suggestions?

Bill, W6WRT