" writes:
The first application of polyurethane finally dried on my red oak
baseboard. I sanded the baseboard and used a tacky cloth to remove the
dust. Should I wipe down the baseboard with a rag dipped in mineral
spirits before I apply the next coat of polyurethane?

No. Poly uses a mechanical bond between coats, you want as little as
possible between coats so as to get the best bond. Just make sure you
get the dust off, that's all.

And I hope by "finally dried" you mean "I waited as long as the can
said to wait". If you don't recoat in the time specified, you need to
wait at least a week or two (to fully cure) and sand before recoating.
If you recoat in the time specified, you only need a light sanding (to
remove raised grain and such) as the poly hasn't fully cured so it
will bond with the next layer whether you sand or not.