I'm refinishing an oak table top. Got it sanded down smooth, stained, then applied 3 coats of Benjamin Moore Stays Clear acrylic polyurethane, lightly sanding between coats. But after the 2nd coat I didn't sand much because I was afraid it would damage the finish. My 3rd coat went on like glass, but now that it's dry, the wood grain is quite raised. Is there anything I can do at this point to get the wood grain smooth again? I think, after reading, that I should have sanded more in between coats, but that's water over the dam now. Thank you for any help.
A common mistake with water based poly is application that is not thick enough.
Give it a light sanding then apply a final heavy coat (or two) and it should come out beautifully.
I sand between coats. Making sure the acrylic is dry. Cleaning the dust off before reapplying is very important. If you want a glass smooth finish, use 400-600 wet sandpaper between coats. When it looks good a very light sanding and a final coat will make it look better than a pro job. I can say this because pro's don't have the extra time for a few additional coats. The extra coats give more depth to the finish. A thick coat has more of a chance for bubbles or brush marks where several thin coats lightly sanded between looks like glass.