Despite constant attention to heat and RPM's, occasionally an interface pad or mandrel will separate.  Very tempted to try hot melt glue to get more use.  Anyone from New England or elsewhere try to repair these?

I never thought it was worth the effort either. If I where to try I might give JB Weld a go since it can handle high temps.

I think you would be better off learning how not to create enough heat that causes the pads to come apart. (Hint: worn sanding disks produce a lot of heat)

I have had good luck with adhesive backed Velcro you buy at a craft store or at JoAnn Fabrics.  I don't remove the old Velcro, just sand it smooth to accept the new one.

I've used Shoe Goo, when I've torn the pad in half because of too much pressure.  Vinces wooden wonders sells replacement velcro for the pads.

I try to keep a additional thin pad on my mandrel and it gets replaced as needed.  The mandrel doesn't wear out that way. 

Good tip Don,
I would add that I have collected many different mandrels and pads over the years with varying degrees of longevity. Some don't last long at all while others I have seem to last forever. all regardless of price.
There are too many differences in these products to have an answer that easily covers them all. Differences like, open-cell and closed-cell foam of varying densities, standard and micro hook & loop fastening, different diameters and so on.
These tools aren't as cheap as they used to be just a few years ago, I would like to repair or make my own specialty tools if need be and save money at the same time.

As I mentioned before, maybe someone with knowledge about the proper adhesive to use could chime in and give use some pointers.
Thanks for posting this Don

I buy a 15' roll of industrial strength Velcro from Wal Mart or a sewing store ... $20.  Plus, a $13 can of 3M 90 spray contact cement.  When a disc holder gets worn, I cut a 2" square piece of the fish hook Velcro ... remove the adhesive protecting plastic and spray both the Velcro and the mandrel with the contact cement.  Wait about 10 minutes and put them together and you are in business with better gripping than you had when the mandrel was new. I have several mandrels and I change mandrels each time I change grits.  That way I avoid any heat that may have built up on the previous grit. 

Also, the backing on the 80 and 100 grit discs that I use  tends to not be very strong, so if I'm sanding something that is particularly rough I may stick the fuzzy side of the Velcro onto the back of the disc or even onto a piece of regular sandpaper.  I work with lots of cottonwood and you may get 1 out of a 100 bowls without tearout.  The only way I know to take care of tear out in these soft woods is to aggressively sand it out. 

I make several hundred bowls a year and have to buy new Velcro and glue about every other year.  This makes my mandrel expense about 1/2  cent per bowl.  I hope this helps ... it works and is an easy fix.