[Richard and Rhonda]

The prooblem with ANY adhesive and aluminum is that the surface of the aluminum oxidizes very rapidly. The oxidation causes the adhesive to delaminate. Think about trying to get glue to stick to a heavy rusted piece of iron. Same thing with AL, only the oxidation is not as pronounced. Even if you scuff it, it oxidizes within seconds.

The redneck way of bonding aluminum is to put the epoxy on it, and use a scrub brush to scuff the surface. The epoxy keeps the aluminum coated and the air away from it. Messy as all get out though.

Yes there are some very special surface treatments that can be used to promote adhesion on aluminum, after all many aluminum cars like Lotus are bonded, not welded, together. Probably the most common one is something called Allodyne

My door is also beginning to separate a little. When it gets bad enough, I'll clean as much of the goop out as I can, and go down the rivet road.