I have what may be a couple silly questions. When putting pins or nails in the horn to hold the two pieces together (or to put on horn rings) do the pins or nails just stick out inside the horn or do you somehow bend or peen them over on the inside? Also, is any type of glue used as well?
Nothing silly about the questions. When I make one of these 'combo' horns the pins, nailsn whatever I use protrude into the interior. I drill the holes smaller than the diameter of the pin, that way the pin is forced or swedged into the hole and has a hard time working it's way out.
I use glue, Titebond, smeared liberly on the inside of the top most horn. The glue will help in holding the two together and makes a somewhat airtight (but not always) seal. I make sure to rough the interior of the top horn and the exterior of the bottm horn on their mating surfaces...a little insurance for the glue to hold onto something.
After the glue has dried I use a heat gun to heat the joint as I smear on tiolet bowl wax ring (unused of coarse) The wax ring is very pliable and the heat allows it to flow and make a water tight as well as an airtight bond.
That's about it.....I'm pretty sure that Tim Crosby does about the same when combining two horns.