Depending on the look you're after, consider de-waxed shellac as a sealer. A one-pound "cut" is good for this purpose, if mixing from flakes. Shellac is one of the more water-resistant finishes, and the first couple of coats go on very quickly due to the rapid drying time. Many "sanding sealers" are actually 1# cuts of shellac. If you buy pre-mixed in a can, test it on scrap to be sure it's not too old to cure.
Shellac (de-waxed) also has the advantage of being able to go under most other finishes, or on top of most other finishes to isolate layers of otherwise incompatible finishes.
Last edited by Ralph Barker; 01-06-2011 at 09:50 AM.