Hi all,
I'm trying to put a polyurethane coat onto a bookcase I'm building. Since it's a prototype, it's made out of cheap, soft pine. I've got it stained, and I'm trying to put on the final coat of polyurethane. But I keep getting small bumps about 1 mm in diameter in the polyurethane coat. If I sand them down and put on another coat, they come back (although I'm not sure if they're in the same spot).
This seems to occur no matter how thick or thin I put the polyurethane on. When I apply it, I've tried both not dragging the brush across the rim of the can and just knocking off the excess. I wipe down the surface after sanding.
I think I've got about five or six coats of varying thickness trying to get rid of these bumps. What the heck am I doing wrong?
Thanks in advance.