There are lots of ways to join parts and fill/smooth seams and gaps. Clockwise from top left: Tenax 7R liquid “plastic welder”; Testors liquid plastic cement; Zap gap-filling super glue; Pacer Z-7 debonder (always keep within arm’s reach in case your other hand becomes glued to something); Loctite super glue gel, great for filling big gaps or tacking pieces in place; Micro Kristal Klear, thick enough to fill in small, clear areas (such as airliner windows); Elmer’s white glue, which gives you time to work and dries clear (good for canopies and windows); similarly, Testors Clear Parts Cement & Window Maker is good for glassy applications; Devcon two-part 5-minute epoxy, tough as nails when cured; Apoxie Sculpt two-part, water-soluble putty; and Duco plastic model cement (the tube glue returning modelers remember).