We are preparing a set of samples for a large area of rift white oak. This project includes solids and veneers.
The owner wants a light color--he prefers the color of unfinished white oak. We have bleached first, to create a light background from which to add color to achieve a "natural" finish. Some darker white oak boards turn from nicotine beige at the first application of bleach, to urine yellow as more bleach is applied. Any nifty chemical solutions to counter-act this?
The client and architect have both specified a minimum build, low maintenance finish. We use a two-part polyurethane from Ilva. Ilva is non-yellowing, very scratch, water, chemical and wear resistant, has excellent clarity and is fast build.
Unfortunately, the build properties don't allow us to tone without adding significantly to finish film thickness. In the opened grain of oak, this starts to look very "plastic”. Ideally we would apply a seal coat, as thin as possible, following this with an equally thin top coat. We want to avoid staining as this will result in coloring in the open grain.
If you want to even out the color of the white oak and make the light and dark areas blend more, consider a "sap" stain. Apply it to the lighter staves and mouldings to make them blend better with the darker. This obviously won't make them lighter--just more consistent. A sap stain is made fairly easily and some manufactures even offer one for use with their system.
If you want to make your own, here is a starting point. Use a solvent of choice (I like acetone), add a little binder, about 5-10%, vinyl sealer works for me, then add pigments to get the desired color. This will typically be a combination of raw umber, red, yellow, and brown.
Bob Niemeyer, forum technical advisor