Hardwood floors for a bathroom countertop
I've been doing some research on what products would be best suited for sealing a wood countertop in the bathroom, but would like some advice from some more professionals. The product that I'm leaning towards is Waterlox brand Tung Oil because I want the natural look of the wood to show. I know that an epoxy based sealant would work best around water and other chemicals, but I don't want that thick glassy look that they produce. I will be using kumaroo 3" wood floor planks and will be gluing the t&g joints, as well as nailing them to a subfloor base. What would you recommend for a sealer and then followed by what type of sink? (undermount, drop-in, or vessel)
Re: Hardwood floors for a bathroom countertop
I would be highly reluctant to use wood as a vanity top in a bathroom. Baths have wide swings in humidity, the enemy of wood stability. Note that before wooden floors are laid, they are allowed to acclimate for several days to adjust to the humidity of the house. Further, flowing water is NEVER recommended on wooden floors. Yet, your vanity tops will be constantly subjected to these elements. Wooden tops are sometimes seen in kitchens, but the conditions there are more controllable.
If you choose to proceed, the question is what to use on it? Tung oil does give a warm patina to wood, however, it does not offer much protection against humidity, water and chemicals found in sundries. You will be crying when the first ring from blue mouthwash appears on the surface!
I agree that urethanes do give a plastic look. There are ways to lessen this. Many woodworkers like to first seal wood with a DE-WAXED shellac. De-waxed shellac will bring out the warmth of the wood grain before finishing it with a urethane. De-waxed shellacs are often called universal sealers. Zinssers' brand is called "Seal Coat". Regular shellac is not compatible with urethanes and many other finishes. A low sheen urethane will also minimize that plastic look.
If you go ahead with your project, I would make sure the moisture content of the wood is as low as you can get it - 8% or lower. I would then seal and urethane ALL surfaces of the finished top, including the edge from the sink cut-out.
An undermount sink would leave you with a very vulnerable end grain cut out. I don't know how that would hold up in a bath situation, especially if this is an everyday bath and not just a show guest bath.
If you go with a urethane, I would use at least 3 finish coats in addition to the de-waxed shellac sealer.