Sasha wrote:
What's the difference between oil based and water based polyurethane?
Water based poly has lower odor and dries faster. If oil based poly
does not have any advantages over water based this makes water based
poly a clear choice. Maybe there are finishes that water based poly
cannot be used on or is not recommended?

The same question applies to water based and oil based stains.

http://www.rd.com/content/openConten...ontentId=19556

http://www.woodzone.com/articles/wood_finishes.htm

google is your friend...