Question
I have encountered a problem with joints in sanding belts. I suspect humidity has loosened the taped joint. Someone must have encountered this problem and found a method of repair. I would replace them, but I have about 50 that are affected, plus long wide belts on the edge sander that are bad. The joints appear to have been done with some kind of tape that resembles filament package tape.
Forum Responses
(Adhesive Forum)
From contributor S:
The tape used to splice belts is a very specialized adhesive that is shipped and stored in dry ice. The application process then requires the belt to cure for 24 hours. An off the shelf adhesive would not have the strength with the shear pressure on the seam.
How old are the belts? If these are not very old, your abrasive supplier should be willing to replace them. It isn't uncommon to have a bad batch from a factory. They may already have complaints on the lot you have. There are shelf life issues with abrasives, but it's usually a few years. Belts, especially, will have problems, especially under the conditions you describe. We've had belts for upwards of five years that have maintained their splice. They are not stored in an environmentally controlled environment, but they are kept in their cartons which protects slightly from the variations from a very rainy week to a dry week. Now if you are buying a no-name on the internet, all bets are off. You get what you pay for.
If we made a belt today, as a previous person stated you would not be able to use it as the glue needs 24 hours curing time (we prefer 36). So, beware the great deal on a bulk amount of belts. It could have been seamed for a long time and ready to pop!