Finishing question

[TominZebulon]

I am in the process of building a vanity for our bathroom out of walnut. There is also a walnut shelf for behind the tub. That has been completed and is ready for finishing. Since I will want them to match, and the vanity is nowhere near done, I need to figure out what will look good. The LOML told me she wants it to look natural and "not shiny". However, it will be in a bathroom, so lots of humidity! While I do not like the idea of putting polyurethane on it, I do not know what else I could do for the humidity protection it will need and since the vanity will get some heavier use, it will need to be durable. Any ideas?

[Howard Acheson]

>> do you try to finish the entire workpiece, so that no humidity can enter from underneath, behind, etc the boards, or just the visible surface areas?

For something being used is a high humidity area, it's best to finish all surfaces. But, no finish, short of encapsulation in two part epoxy, will prevent moisture from getting through the finish. A finish just slows up the transmission of moisture.

>> what is your preferred brand of poly? Do you use a non-yellowing one?

Avoid poly varnish if you want the most water vapor resistance. Particularly avoid any poly that is marketed as "spar" or "marine". Spar or marine exterior varnishes are formulated with lots of oil so then remain soft and flexible. This allows them to remain adhered to wood surfaces that have movement due to rapid and large changes to the outdoor or marine environment. These products are also less water vapor resistant and durable than interior varnishes because of the high oil content. Don't be fooled, an interior rated varnish or poly varnish is quite a bit more tolerant of and protective in a high moisture environment.

The most water and water vapor resistant one-part finish is a good non-poly interior rated varnish. It contains a higher percentage of resin to oil making it harder and more water resistant. It's also clearer and will look nicer. Look for Pratt & Lambert #38, Cabot 8000, Sherwin Williams varnish, Waterlox Original Gloss or Satin, or, Behlen Rockhard.

Finally, light least yellow varnishes are those made with alkyd resin and soya oil. The P&L #38 and the Sherwin Williams fit that bill. Cabot and all consumer grade big box poly varnish are made with linseed oil and are fairly amber. The Waterlox and Behlen are made with phenolic resin and are the most amber of all.

[Gregory Paolini]

As a rule, I try to apply finish where ever possible - It goes back to the theory of balancing the wood. If you apply finish to one side, then moisture can enter the other, and cause cupping or warping..

As far as brand of poly, I just use minwax. I'm real big on just using what's commonly available - If I have to hunt it down, then it becomes a pain to get... And I'm pretty lazy.... I'd rather just run to lowes or Home Depot

By the way - For anyone interested, I'm conducting a full day finishing workshop on November 7th in Waynesville, NC. You can find out more details at my website http://www.gregorypaolini.com/WWClas...s_Schedule.htm