On Wed, 9 Dec 2009 20:55:09 -0800 (PST), "
wrote:

Has anyone had experience with a water protective finish for MDF? I
have a work table with an MDF top, and I briefly set a glass of ice
tea on it, and the wet spot swelled up. Fortunately, it wasn’t
permanent. I saw that Pat Warner saturated his router table top with
Watco. I wonder how that worked out.

I have on hand Watco, Exterior Watco, Waterlox, and several types of
varnishes. What would be best? I plan to submerge the top, but I don’t
want water soaking in on contact.

Thanks.
Joel

Maybe a polyurethane varnish, floor paint or apply Formica over the
MDF. If unprotected wood gets wet, it will swell.