If I was going to try and fix a delamination 16"-18" long, I'd definitely use Smooth-on epoxy instead of Loctite 420 or other super glue. Smooth-on or a similar epoxy is what was used to originally make the bow, and it's made to handle the flexing and shear stresses in bow limbs. If it's a pretty clean delamination, I would think that it could be fixed with Smooth-on. When putting the Smooth-on on the delaminated area, I'd take a piece of thread (clean unwaxed thread) and work some epoxy down into the spot where the delam starts-- kind of like flossing your teeth, but instead you're trying to make sure you get some epoxy down into where the delam starts. This could help the delam from working it's way further down the limb in the future.
Disclaimer: I'm not saying you should definitely try to fix it. Without actually seeing the delam, I don't whether I'd try to or not. But if I did try to fix what you've described, it would be with Smooth-on.