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discoloration on knotty pine finish

starhav's picture

My name is Maj to all readers!   I have a problem and am wondering if any of you could be of assitance.   Recently, (about 2 years ago) we varnished our knotty pine walls downstairs, and then hung some pictures.   Now we are considering moving, and when I remove my pictures, I find that the walls are darker than underneath my pictures.  Apparently, light has caused this discoloration.   I am wondering what I might do to reduce the discoloration (lighter area) underneath my pictures.   Any suggestions would be most helpful!    Thank you.   Sincerely,  Maj   I can be reached at

(post #54808, reply #1 of 2)

Judging from your description, I'm guessing that you used an oil-based varnish. The varnish that's been exposed to the sunlight has ambered, as all oil-based varnishes will and the wood itself has likely developed a patina.

The easiest way for you to get the lighter areas to match the darker areas is to use a sunlamp mounted in a clamp-on fixture with a porcelain socket to accelerate the process on the light areas. You'll have to mask off your wall so that the light shines only on the area of desired treatment. Try placing the lamp about 16" or so from the surface, but check that distance after about ten and twenty minutes to insure that the wall surface doesn't get too hot. Although some heat generation is to be expected, you don't want to damage the varnish.

Try about four hours of exposure to start and see how things are going. Adjust time of exposure accordingly. If you need to "feather" the edges, you'll have to slide that mask around a bit as the process proceeds to get things to blend in just right when all is said and done.

Knowledge is power, but only if applied in a timely fashion.

Knowledge is power, but only if applied in a timely fashion.

(post #54808, reply #2 of 2)

Thank you for your information,  we will give it a try!  Maj