Most GWS airplane kits come with "contact cement" included in the box. You apply the clear glue to the two pieces you want to join together, you trial fit the two together and let the cement intermingle on the two pieces, then pull them apart for about 15 minutes. The contact cement then starts to cure and you put the pieces back together and the two parts bond.

It's weird stuff, but it's supposed to work well if you use it right. The only problem is there usually isn't any instruction with regard to how to use the glue.