Originally Posted by Mac50L
I used Gorilla urethane glue. A bead along the inner edge so, as it foamed it (theoretically) filled/covered the whole surface area. Not necessarily the best glue to use but it worked for me and no rush to get it on and the pieces clamped together.
After gluing I taped the join with masking tape and rubber-bands while it dried. This (the tape) also helps to contain the glue within the join.
The motor mounting section - I didn't glue round this area so if the motor needs changing at any time, one side can be cut and the "cover" lifted off. That join is simply taped along the top with a short piece of masking tape, probably not necessary.
Did you dampen the material, like in the glue's instructions or lay it on clean and dry?