when ca is used correctly, it should never fail at the joint, only beside the joint. one thing not to do is to tough the parts to be glued with your fingers, you are now adding your oil into the glue joint, which will now decrease the strength by a lot. also, for a good strong joint, the parts should be snug, a loose fit is no good. try to avoid sanding a joint that is to be glued, you are covering the wood pores with sawdust and foreign materials being pressed into the wood, now decreases the strength, you should cut or saw.
glue is only reguired on the joint itself, when you apply glue on the outside all you are adding is weight, there is no structural strength in glue. all that glue does is bond two surfaces together.

take fiberglass for example, the epoxt resin when hard has no strength, it is brittle. so if you have glue on the outside of a joint, you can just peel it off.


just try to have a good tight joint, free from foreign objects, and you'll have one good glue joint. ca is good for most of the model, in high strength areas always use epoxy. for a firewall, never use ca.

good luck,

GB