Reply by WIwoodworker

Hi Steve. If it’s tear out there are a number of ways to reduce/eliminate that problem (planing with the grain, sharp knives, slower feed rate, light passes, etc).

If the spots are more like depressions in the wood then the issue is likely insufficient chip removal on your planer. Check the dust collection path to ensure it’s clear (bench top planers can clog easily especially if you’re taking aggressive passes). If the path is clear maybe take a look at your dust collection system to ensure you have a suitable sized system for your needs.

Just some thoughts that came to mind. Good luck with your project.

-- Allen, Milwaukee, WI