Hi Ed

Sorry to hear about the delaminations or I think more properly, disbondings.  
How was the joint originally prepared?  I'm always concerened abouyt
contamination and like Boeing, I don't allow lubricants into my bonding shop.
 This is particularly true of silicone.  But what adhesive was used?  There
are a number of bonding adhesives that are much better than the Jeffco (if
that's what you used).  Also sanding and cleaning is critical just prior to
bonding.  I know they say to use industrial grade solvent for cleaning but
that has about 3% impurities as I remember.  Reagent grade would be better
and a lab towel like a Kimwipe is better than paper towels.

Good luck on the repair!

Dan Newland