My wife and I are making nightstands for one of our guest bedrooms. We used poplar wood since this is not really our forte and wanted to start with something cheap. They are mid century modern style and have come together extremely well. (Much better than we expected.) Until we applied Wipe-on polyurethane. Small particles got into the poly while it was still wet. I know if we sanded it down we could reapply but we have Minwax wood stain on there and don’t want to ruin the stain. Is it as simple as using 320 or 400 grit sandpaper and lightly sanding with the grain and then applying the next coat? I’m thinking we may need to move these outside to get away from the dust in the shop. Don’t laugh at me too hard! I typically only use oil or wax finishes. Or my favorite Shellawax on my turnings. This polyurethane is all new to me.