who makes belt sander belts that don't break?

[Jeff Ramsey]

If you buy direct from Klingspor, it's $100 ($300 for free shipping). You can buy Klingspor products from distributors, but the 1-year warranty on the glue will dissuade me. From their site:

• BuyersKLINGSPOR Abrasives sells to businesses and distributors only. For single purchases and small quantities, visit the KLINGSPOR's Woodworking Shop. Accounts created at the Woodworking Shop cannot be used for Klingspor.com and vice versa.
  
• Minimum PurchasePurchase a minimum of $100 to place an order.
  
• Order $300, Get Free Shipping

[Jonathan Jung]

www.woodworkingshop.com is the official Klingspor "retail" site, and ironically their prices are sometimes better than buying direct from Klingspor. And no min. order.

[Frank Pratt]

I've used 15 year old Klingspor belts and never had one break. My current stock of belts are anywhere from about 8 - 15 years old and I've never had one break. They are stored in a dark drawer in my shop, where it never gets above about 25* C in the summer or below 6* C in the winter.

[Lee Schierer]

I found that my Porter Cable 3 x 21 belt sander was doing the same thing with brand new belts. I examined the tension adjustment and fount that if I inserted a shim so that the tension leaver could apply full tension that the belts would still work just fine, but they wouldn't break for a long time. I think I added about .030-.040 thickness behind the lever to get the best life without slippage. Here is the original post