2.8 oz Dap 684 Clear 100% Silicone Rubber Window, Door & Siding Sealant

This stuff is great for gluing unlike materials together. Like aluminum expands and contracts a lot with a change in temperature changes , So say you made a bird feeder and plan to attach it on a window, using an aluminum frame. Then using a thickness of about a half inch will allow the flexibility of the silicone to weather both hot & cold. Using a step latter or something else to hold the bird feeder or what ever in place, Then mark the gluing area with tape. Then move the bird feeder and apply a generous amount o f silicone to the glass and also the feeder. Then when it is about 40° F then glue the previously glued areas together. Then you have bird feeder/feeders right in plain sight for years to come. If you get tired of it, a razor scrapper will remove it cleanly.

Ignore the previous review about back packaging. It was a user error, because the user didn't know that almost every caulk gun has a needle on it to puncture the inner seal before use. If you don't puncture the seal, you are going to blow out the back of your tube of caulking or sealant. Read the instructions people.