Belt Sanding Timbers

I am using a Porter Cable 4" x 24" belt sander to finish my timbers. The problem I'm having, is that the belts keep breaking. I do my best not to push down on the sander. I'm using 3M, 100 grit belts. Does anyone else have this problem? What do you all recommend using for belts? Continuous use just seems to heat up the platen and belt too much. Comments....

While I have had good luck with the 3M belts, I have better luck with the Klingspor belts. If I am using pine I buy the cheapest belts possible because of the pitch loading in the belts(One just goes though them faster) but on oak I buy a little better belt. If you are a business you can easy get a business account and save a bundle. Have never been able to buy the 3M belt at wholesale prices. We do have the same sander as you.
Brice

Thanks for the info on the belts. Where do you buy the Klingspor belts? Also, I've been using 100 grit belts to finish my timbers. It seems to look alright. Do you (or anyone else) recommend a finer grit. I don't have two large belt sanders (one for coarse grit and one for fine), and really don't want to sand twice anyway, that's why I initially went with 100 grit. Comments anyone......

Never heard back from you Brice. Where do you buy the Klingspor belts? Also, what grit does everyone else like to finish their timbers with in the shop or after the frame raising?

Sorry for the delay J.,
I order them direct for Klingspor and easily setup a commerial account. Thus, buying at wholesale.
Brice

We use 100 grit on fir and pine. We sand and finish in the shop. CB.