So I got a great deal on a used 25" Performax drum sander this past weekend. It needs a little repair - specifically, one of the drums needs to be replaced. But it works fine as a single drum unit until I get around to it.
Anyway, I decided to try it out on a Ponderosa pine slab that I have around. About 15" wide by 3' long and maybe 2" thick. I've had this in my shop in bone-dry Colorado (summer humidity can reach the single digits) for about 9 months. Not sure how long the sawyer had it, but it was stored inside, stacked & stickered, when I bought it and was from timber dead at least 5 years (forest fire salvage). Felt dry then.
Anyway, I was taking light passes - about 1/8 of a turn. Don't know what that comes to in inches. And slow feeds. But the paper loaded up like crazy, particularly over knots. The 80 grit that was on it succumbed quickly. Swapped it for some new 60 grit Al oxide, and that only lasted for about 6-8 passes as well.
I tried using one of those rubber sand paper cleaning sticks between passes - and a wire brush when it started getting bad. I'm running dust collection on it.
Any ideas? Maybe a heavier grit for roughing it in? Or is this just what I should expect with a resin heavy wood like Ponderosa knots?
I ran a big walnut slab through several times yesterday, and no loading at all!