Helping a neighbor

[Sandy Rose]

I have a neighbor that is getting ready to start building a counter for his master bathroom. He wants to make the countertop out of soild Oak that he wants to stain with two sinks that will just sit on top of the counter. I brought up the concern that the oak, over time could warp since it's the main bathroom in the house. After talking about it for a while, we thought of staining and then coating with more than normal layers of polyurethane. Has anyone done this, or have any suggestions to make the wood inpervious to moisture?

 

[Trent Mason]

I would look into something like an epoxy bartop finish.

I second that motion.

 

[gator]

Whatever finish is used, be sure to do all 6 sides equally. Leaving any side/edge unsealed with result in moisture absorbsion and thus, warping.

George

 

[McRabbet]

I used Behlen's Rock Hard Tabletop Varnish on our kitchen table three years ago and water just beads up on it. It gets daily hard use and the finish has stayed scratch-free as well. It is a gloss finish, but can be rubbed out to any desired matte finish. I have used it on two other projects and it has held up very well in both cases.

In an application like the one you are contemplating, it is critical to keep water from getting to the end grain at the sink cutouts and along the edges of the top. Be sure that these surfaces are well finished, too, as well as caulked. And, of course, be sure to finish the underside of the top to prevent any differential absorption of moisture that would lead to warping.

 

[junquecol]

Despite sealing for the moisture that can be seen, this large of a slab is going to expand and contract quite a bit. The changes in relative humidity are drastic in a bathroom. You will definitely have to allow for movement. To make matters worse, the lavatories aren't going to expand and contract. Be sure to use a caulk that remains flexible. Silicone would NOT be my choice for this application. Bruce

 

[Makinsawdust]

IMHO, this is one of those things that could easily turn into a disaster in short order. Even armed with the best of finishes and know how there could be problems. Next thing you know, it's my neighbors fault cause he/she said to use xyz. Ask me how many times I've had to explain that I can't stop wood from acting like wood!
Rob