just about any good (non-wood) adhesive can be used. epoxy is good. I use thick CA. I also use thin CA on any porous areas. When gluing in the tube, if the antler is porous at the exposed ends at the tubes, I drip one drop at a time into the porous areas and let it wick into the porous portions. Keep adding one drop at a time until the drops stop wicking into the blank. I then shoot it with accelerator. No need to fling uncured CA everywhere when I start up the lathe. While turning, if I encounter any porous area, I stop the lathe and repeat the wicking procedure. May have to do it 2 or 3 times before getting down to the needed dimensions.
Note: I normally choose antler that is denser and I rarely have to 'stabilize' it with CA, but every now and then.... blah, blah, blah. ymmv..
