ORIGINAL: drewhosick
I'm thinking about building instead of ARFing it this time around for my second plane. I've been reading some build threads and all but here's my question. I've seen people using different glues for different purposes which caught me a little by surprise actually. Not that different glues don't have a different purpose but for example, why does everyone seem to use CA for wing ribs. I would have thought epoxy(being as strong a bond as it is) would be a select choice for that. In fact, I would have thought that if anything, you could use epoxy everywhere on the plane because of it's bonding strength.
If not, why and what do you use for what parts of the plane?
You also have to keep in mind that, not only is epoxy extremely heavy compared to CA, but the bond is only as strong as the material. Wing ribs are generally made from especially thin balsa. By itself, it is quite weak. It'll break just as easy by itself regardless of the strength of the glue. So if epoxy offers no benefit in an area, why pay the weight penalty?
Use epoxy where it absolutely cannot come apart AND there's no other structure to help the bond. Wing joiners, tail feathers to the fuse, wing mounting plates, firewall, etc.
interlocking parts make themselves strong through the design... all you have to do is keep them together... CA! wing ribs, fuselage, built-up tail feathers, etc.