Without a picture, I can't help much...if the problem is just old varnish and shellac which has darkened over time, you can use paint stripper. If there is no finish and the wood itself has darkened, you may be able to do a wash over it--lime wash, I think? I have no experience with bleaching wood, but I'd think the results could be highly varied, and difficult to get an even tone over the whole area.

You might try a simple washing with tsp, perhaps there is just a lot of surface grime? As a last resort, sanding would be a possibility, but beading could mean a lot of detailed hand sanding.

Definitely try to see which solvent dissolves the finish. Alcohol will dissolve shellac; mineral spirits or turps will affect varnishes.

That being said, even after you find which product will remove the finish, you may still have a nasty mess on your hands as cleaning out the base of the groove in bead board can be a real pain: think dental tools and lots rags!

I have the same issue and I am considering taking the beadboard off and doing it outside, on a flat work surface. Mine is covered in highly-crazed shellac, but readily reliquifies with alcohol. Even water will lighten mine, but unevenly. My beadboard actually is two "strips" wide, but with full T&G between these boards. It's easy to remove once you detect the blind nailed corner starting (really the ending) point. Removing would allow insulating behind it, too. That would be an improvement in my otherwise uninsulated house.

In my case painting is not really an option w/o stripping as the paint wouldn't lie smooth and flat with crackly-crazed shellac underneath. I may try to clean it up enough for painting and then see if I like it in a natural state. If not then I will paint it, even though you can only paint beadboard a few times before the pattern is obscured, especially with modern thick emulsion paints.

HTH,

L.

Thank you for not painting! Yes, definitely remove the old finish & see what you have - prob just shellac which darkens over time and easy to remove. Some light sanding wouldnt hurt, to smooth the surface & even out the tone - then re-shellac with a light color shellac or clear finish. I imagine the refinished wood walls would give a beautiful golden glow to the room ... instead of dreary dark brown. I don't think there would be any need to bleach or whitewash the wood.

"mineral spirits or turps will affect varnishes. "

Barely.
It will remove grime more than anything.

The curing of varnish is not a reversible reaction.

Stripper breaks down the finish chemically (not the same as just simple dissolving).

"Some light sanding wouldn't hurt"

Um, it may very well reveal a different color of wood, at which point you'll have to decide whether you want a blotchy look of sanded vs. unsanded areas, or commit to sanding the whole thing.

It depends on what you want to do, and the wood you're working with. I've no doubt that kashka was able to lightly sand something and get even, consistent results, but it totally depends on the species of wood, sun exposure, other aging and oxidation, staining, finish, and probably a bunch of other variables I don't even know about.

There are threads in this forum where contractors spot sanded antique woodwork and the homeowner was posting trying to find a fix. I could almost see the tears running down my monitor; they were pretty upset. So, proceed with caution.