Preventing planer problems

My planer seems to be struggling to feed boards through. When I help them along after getting stuck, they have black marks. The knives are brand new. What's going wrong?
—Mitchel Streeter, Ephrata, Pa.

Sounds like dirty feed rollers, Mitchel. Sawdust buildup on the rollers—caused by resinous woods or inadequate dust collection—saps the rollers' gripping power. Black streaks appear where the rollers rub against the immobile wood, and burn marks appear where the knives continue to spin.

To fix the problem, unplug your planer, fully raise the cutterhead, blow out stray chips and dust with compressed air, and wipe the rollers with mineral spirits and a shop cloth to remove any sawdust buildup. For most planers, you won't be able to freely turn the rollers to clean the opposite side. So, plug the planer back in and switch it on momentarily. After it stops, unplug the machine and clean the newly exposed roller surfaces. Repeat as necessary.