I'll second the CA glue, however go a bit farther and specifically recommend GluBoost Ultra Thin. The GREEN bottle. They have three commonly used for wood finish: Blue (thicker), Orange (Thin) and a newer product Green (Ultra Thin). You'll also want a bottle of their GluDry accelerator.
The reason I specifically recommend GB Ultra Thin, is it is super penetrating. I don't know of any other CA glue that is as thin as this, and nothing else seems to penetrate as well either. This stuff can go fairly deep. It will not totally saturate the wood, unless its fairly porous, but it will go I'd say most of a millimeter deep, maybe more depending on the wood and how well it wicks it up before you blast it GluDry.
I am curious about more details. Are you trying to stabilize the entire blank before turning, or would you, say, trim off corners and then start roughing, then start sealing? If you need to seal the whole blank, IMO, vacuum+heat is still probably best. I don't think epoxy is going to help as much, unless you could find something pretty thin so it wicks in. That's kind of the benefit of something like Cactus Juice is that as you suck the air out, its thin enough to flow right into the wood. I agree though, it can be a bit of a pain. I've used pentacryl in the past. I don't think I'd say that stuff really stabilizes, although I haven't had a ton of experience with it. The stuff I used was supposed to replace water, so that wood movement would slow or stop. It still seemed to remain "wet" though....
Anyway, for the GB ultra thin to work, you probably want to trim off the corners of your blanks, and using really sharp tools, make some initial cuts to get things fairly round. Then saturate with GBUT, give it some time to soak in, then a quick blast from GD. Do a bit more turning, and if you see you are turning through the sealed wood, re-seal those spots with more GBUT, let it penetrate, and quick blast with GD.
I've done this with a decent number of pens now that were made from either softer woods, or when I knew the barrel wood would end up quite thin over the brass tube. Final finishing was then, of course, done with GluBoost Thin (orange) and normal GluBoost (blue) if necessary. GluBoost is DESIGNED as a finish, so when you sand it well (wet stand is best, I generally prefer Zona paper but micromesh works too), and sand right down to the finest grit (1 micron with Zona), then polish and/or buff to eliminate patterned scratches, the final finish is glassy, brilliant and REALLY brings out the chatoyance. Should work just as well for rings as pens.
