The Power of the Sun
Article - June 30, 2010
You’ve probably heard woodworkers discuss how numerous species can change color after UV exposure. Its a common practice to give your cherry projects a couple days in the sun to accelerate its color shift. The cherry goes from a light brown/pinkish/salmon color to a deep rich medium brown with red undertones. If you haven’t tried it yet, I highly recommend you do.
Well thanks to my pure laziness, I have a very obvious example of the effect of the sun on cherry. I recently picked up materials for the upcoming Chest of Drawers build, and due to pure laziness on my part, I left them in the pickup for a full day yesterday. The sheet of 1/4″ cherry ply was partially covered by a piece of Baltic birch. So when I went out there to bring the materials in, I just knew I would have a two-tone piece of plywood on my hands. The picture at left tells the tale. If you look closely, the birch plywood was also affected by the sun. You can see the strap marks left by my tie-downs.
So why am I not concerned? Well, the side you are looking at is not the show side. So if there is a little unevenness on the inside of the case, I am not too concerned about it. Also, my case sides are small enough that they can be cut completely out of the lighter portion.
Now if you run into a problem like this and it IS on the show side, here’s what I would recommend doing. Sand the surface lightly to even things out. If you are using plywood, you don’t have much material to sand so you have to be gentle. As a result you will not be able to remove the color difference completely. You will still see a line (pictured right after 180 grit sanding). So the next thing I would do is put the entire panel in the sun again. Give the lighter side a chance to catch up. At this point, the difference between the two sides should be minimal. Even after being incorporated into the project, the wood will continue to darken over time and the two sides will even out. But if you are in a rush, you might resort to using some dye or stain. A simple natural cherry-colored dye/stain will even things out without giving the wood an artificial-looking color. Over time, the wood underneath will continue to age and the little bit of dye/stain on top of it won’t be much of a factor.
And most importantly, don’t be a dork like me. Bring your wood into the shop once you get it home! I would love to hear any stories you guys might have about similar experiences with the sun (intended or accidental).