"I do not agree that only loose old cement needs to be taken off... I think it needs to be chemically clean and dry before applying the spray on Contact Cement..."

The directions on the can says only that the surface has to be free of wax and oil. Certainly, you can't overprep a job like this, but the cured adhesive I encountered under my original hood pads was not coming off without a struggle -- so I concluded that it wouldn't be a problem as long as the new adhesive stuck to the old stuff.

After a few goings-over with a brown Scotchbrite pad soaked in adhesive remover, any old glue that was likely to pose an adhesion problem down the road was gone. The process also resulted in a nicely roughed up surface. Final step was a wipedown with prep-sol, similar to the way you'd prep a paint surface for a respray. Three years later, the pad on my coupe remains firmly affixed. I took a similar approach on a wagon I bought more recently. The jury's still out there, I guess.

Psfred, if you managed to apply three coats of adhesive to the pad using only half a can of the stuff, you are the maestro of aerosol! I had a little left over from the second can on my most recent pad, but not that much.

Russ M