I have used CA and epoxy for this. I prefer CA.
It is my experience that no matter which glue you use if drilling or turning creates too much heat the joint will fail. So I use Medium CA because I can hit it with accelerator and move on to the next joint.
Before I drill I encase! Here is what I wrote in another thread....
When I first started using aluminum for segments I had this happen all the time. I do not drill on the lathe but on the drill press. When I build the segmented blank I build it so that 2 sides are perpendicular to each other. This allows me to square the other 2 sides on the table saw. Once the blank is all squared up I encase it in 1/8 inch ply or hardwood (whatever is on hand).
Before you encase the blank be sure to mark the center of the design on the top. I use a brad point bit turned by hand to put a little dimple so I can find it easily. Also be sure that your casing does not extend below the bottom of the blank. The bottom should have been squared to the sides and you want the blank to rest squarely on the bottom when on your drill press table.
Now you can drill away with confidence that the blank will not blow up! One word of caution here. If you use a brad point bit to drill a blank with an aluminum segment you will have trouble. The center point will penetrate the aluminum and then the outer points will score through leaving a disk with a hole in the center. This disk spins with the bit and does not allow the bit to penetrate further into the blank. All of this causes a bunch of heat which causes the blank to blow up DAMHIK! Use twist bits instead, they will make shavings of the aluminum that will be ejected up the flutes.
Once the drilling is done you can slice off the casing at the bandsaw or just turn it off on the lathe. It sounds like a lot of work but repairing the blank 3 or 4 times is more costly and way more frustrating!
Two other things I learned the hard way:
1.) When you design your blank be sure that any aluminum segments fall on the brass tube. If they are not supported by the brass the joint can fail while you are tuning it on the lathe.
2.) Be careful while squaring segmented blanks, they can blow up during this step as well. If I am concerned I will CA glue cotton twine around the ends of the blank and then soak it with CA to form a casing. This turns off easy enough at the lathe.
