I'm having breakage/short life issues with sanding belts that I've never had before. My sander is a Bosch 1273 in good shape, in spite of it's age. The base pad assembly, drive belt and the edge "rub guide" have all been replaced, in years past. Belts are easily adjusted to track properly.
FWIW, I'm a serious level, life long, wood freak, with much experience and been around shops all my life. I taught tech school and worked in skilled trades prior to that.
Klingspor 4 x 24" AO belts are the current belt.
I had this problem a few years back and Klingspor replaced them on warranty. The replacements have the same problem in that the taped butt joint falls apart as soon as the belt warms up and long before it's anywhere near used up. In fact, belts placed on the sander after it gets warm break even faster than the first one used in an operation. It seems the heat releases the tapes adhesive. Klingspor warranty is 2 years and they say to only buy a less than 2 years supply or no warranty later. They also say belts must be stored in a climate controlled area. My dedicated shop is located in Eastern Kentucky near our home. I do run the A/C in hot humid weather and have electric & wood heat too but also open up the shop during nice weather.
I have never had this issue with lapped joint belts! I have used a typical rubber cleaner stick to extend belt abrasive life to the extent that often belts were no longer useful after long usage.
Many manufacturers are using the filament tape joints now. They actually brag as to how the belts can now be run in both directions. My experience with taped joints tells me to stay away from them! I have had good service from Sungold belts made in Korea previous to Klingspor belts. There is zero issue with Klingspors abrasive-it's about the taped joints! I've read many Amazon reviews for taped joint belts and they get anywhere from similar to my experience to 5 stars, all depending on who's using them. Weird huh?
I researched this via google & Woodweb has a 2012 post with similar problems to mine.
I'm out of belts and need some NOW!!! Don't know what to buy? I'm calling Sungold Monday to see if they still lap their joints or now using the tape.
What say you???