There are a lot of glues we can and do use, as pointed out by previous posters. I tend to keep about 10+ adhesives in my hobby shop. The adhesive I will use for a particular bond will depend upon everything from my mood to what I am bonding to other issues. Often, there is more than one adhesive that will do the job, so a lot is personal preference.

Glue weight is important on planes. However, nearly any glue when used properly will produce a light airframe/wing. When purchasing glue, keep in mind that all glue has a shelf life, typically around 1 year, but this does vary.

Adhesives I use, with my personal preferences in their use. Probably 99% of what I use is polyurethane, epoxy and CA.

Polyurethane – Strong and bonds to nearly any material. This glue can be used very sparingly, but will still make a very strong bond, which I believe makes for a very good strength/weight ratio, but I’ve never tested. It foams when it cures, causing it to work into all the spaces in a joint. It also has a long working time out of bottle in the range of an hour. It sands very easily and cleanly. Low to no odor. My glue of preference for sheeting cores, but I have used for wood airframe bonding, firewalls, etc. Shelf life is about 1 year.

Epoxy – Only about a zillion flavors. The 1:1 mix common to our hobby works good on wood, foam and most composites. I don’t believe this glue is significantly heavier than other glues; however, it is easy to use too much, so care must be taken to clear off excess. Can be thinned with Acetone, MEK, etc. to make a brush on fuel proof coating. Can be mixed with fillers to change properties. My glue of preference when working with composites, and often for wood to wood joints. Because of the wide range of epoxies, thick/thin, high temp, pot times, ability to combine with filler or use as the bonding agent in a composite, this is probably the most versatile glue I use. Shelf life is about 1 year for most epoxies.

CA’s – Different types, but all work about the same. These glues work well, but can be brittle and are difficult to sand. What is nice about the CA family is their quick and/or predictable (accelerator) set time. Because of the speed, for smaller builds I may use CA exclusively. Otherwise I often use CA as a tacking adhesive to set the part, and then use another adhesive, such as epoxy, as the primary bonder. CAs has a very short shelf life. I swear this stuff has a shelf life of about an hour.

Some other lesser used stuff I keep around.

Rosin Wood Glues – I really don’t like the stuff (just my personal preference) so I rarely use it. However, I do keep some around I use for wood to wood bonds. What I don’t like is the slow set speed and sanding issues. The glue will sand, but when used on soft (contest grade) balsa, the glue tends to ball up and gouge out the wood. In general, where others use this glue, I always use polyurethane, epoxy or CA instead. Shelf life is about 1 year.

100% Silicone adhesive – I often use when mounting fuel tanks.

Hot Glue – a small dab on servo connections (on the outside of course) keep then secure, be it to the RX or an extension.

Spray Contact Adhesive – Perfect for tacking paper templates on parts to be cut or sanded.

Contact Adhesive (in jar w/brush) – I sometimes will use this when attaching covering such as nylon rip stop on small electric models.

Zap-a-Gap-a-Doo – I have no idea what this glop is, but is works well for attaching mounting plates to the inside of cowls, wheel pants, etc. Generally, I’ll use epoxy instead.