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I just finished my first wood-working project ever, and applied the first layer of polyurethane last night. This morning, it looks beautiful. So I have a few questions:

Do I need a second (or more) coat? What do I gain by doing it (or lose by not)? Also, why do I need to sand between coatings?

BlueRaja - Danny Pflughoeft
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The sanding of coats in-between is to give the new coat something to adhere to. It roughs up the surface just enough to give it a bit of grip.

Multiple coats is the same as anything else. Multiple coats makes the coating thicker, stronger and more lustrous.

Cars have multiple coats of paint to protect the body; you paint your walls with multiple coats to ensure even coverage; you poly furniture with multiple coats to ensure durability.

Don't sand to much. Use a very fine grit and just rub over it. The grit should feel like loose leaf paper. You'll have white dust when your done. Make sure to wipe the piece very well with a soft cloth before applying the next coat.

lsiunsuex
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  • I restored a bedroom dresser years ago and we did 3 coats on the cabinet and 2 coats on the drawers; the cabinet will receive more abuse than the face of the drawers. – lsiunsuex Mar 20 '12 at 16:18
  • So, how do I decide if it's worth putting a second/third/fourth coat on? – BlueRaja - Danny Pflughoeft Mar 20 '12 at 16:23
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    Whats the purpose of the piece? A table or night stand or something that will have things being placed on it often I'd say do 3 coats. We stained and poly'd our kitchen cabinets ourselves and we did 2 coats because the handles will be touched more than the face of the cabinet. If its just a decorative piece, maybe 1; but to do a 2nd coat is only going to take you 1 more day. I'd say minimum 2 and if its a table or chair or something that will be used, do 3. I'm sure you have poly left over. – lsiunsuex Mar 20 '12 at 16:27
  • Thank you, that is exactly what I was looking for! The project was/is a storage chest for [Magic the Gathering](http://en.wikipedia.org/wiki/Magic:_The_Gathering) cards, and a set of [Go](http://en.wikipedia.org/wiki/Go_%28game%29) boards. Yes, I am such a geek :) – BlueRaja - Danny Pflughoeft Mar 20 '12 at 16:41