Picture Shadows on Wood Wall......

Gentlemen, I have a 10 foot high living room wall covered in 6 inch wide, 3/4 inch thick, tongue and grooved bevel edged pine planks. The pine appears to have been coated with a shellac or other coating about 40 years ago. There is much lighter wood under where pictures used to hang. Is it possible to chemically remove the old clear finish, then treat the bare pine with another chemical, so that the wall is one consistent color? I would prefer to do this chemically rather than by sanding. Opinions anyone? Thank you very much, Supe.

Hi Supermarine,
I doubt you will be able to do it chemically. The passage of time (light) is not easily removed.
Sanding will do it (eventually) but this is an enormous task. You could sand lightly to clean timber and leave the history there.

or, as I did once, remove all the boards and process then in your shed, maybe with a thicknesser.

Regards,
conwood

As Conwood says light is a very effective medium. Even after sanding you may find the colour difference remains for up to 1/8" depth. However there is hope. You could use a heavily pigmented stain, sometimes called a wiping stain, which is basically a thin paint. This will disguise most colour differences in the wood without hiding it completely, so you can still see some wood grain.

Or maybe go to the Light Side! :D You could bleach the whole surface, and then og for a 'liming' effect that the Austrians do so well. You'll still see the grain too.

Super, Not sure if you have tried a test piece in a corner, but could it be just the original finish that is discoloured and where the paintings were hanging is the original finish color.

I have seen this sought thing on furniture where one part covers another.

Tim