polycrylic

[Cliff Rohrabacher]

http://www.sawmillcreek.org/showthread.php?t=61668

[Robert Waddell]

You can thin with water if you need to. Have you thought about spraying it? I spray it with a HP touch-up gun with great results. Drys almost as soon as it hits the wood and is easy to build in a short time period with little chance of runs or sags.
Rob

[Jim Becker]

It can only be thined very slightly...adding more than about 10% water to a water bourne finish will make for nasty results. Water is only the "carrier" for the finish with these products and you really can't "thin" them in the same sense as with oil based, shellac or lacquer.