question about walnut

[JasonB]

hey Don, my question is about walnut. I have an old crib that my grandpa built for me when I was a baby. It is a natural finish on black walnut and now, 30 years later, it still looks like black walnut, just as dark as the day grandpa built it. Now, some of the projects I have made are begining to lighten considerably after 5 years. and I have seen projects come through our shop where old black walnut was almost as yellow as a bannana! I asume some of this is UV light, but I have also seen walnut that hasn't bleached over the years. what gives?
I have heard things like "they steam the walnut at the lumber yard to darken it up and thats the wood that yellows" but I don't know what I think about that. what do you think?

[bogydave]

Jason
Just curious as the the type of finish your Grandpa used on the crib?

[Don]

Hey, Jason. I think you've got me on these questions. I've also seen what you've talked about on the walnut. I've been in old offices that were paneled in walnut and the wood can take on a yellowish cast. I'm afraid that it's simply and oxidation and UV process. The wood is so dark that for it to be "turned" into "weathered" wood it has to lighten. This lightening coupled with the dark color gives it that sickly yellow look you are talking about.

Now with that being said, some of the older finishes of years ago did not have the UV properties that many do today. The finishes themselves yellowed, aggravating the problem. Of course some of the sapwood in walnut is/can be yellowish to begin with.

Why one piece will yellow and another retain it's color is beyond be. A lumber yard process? Possible - but I would think that would be common knowledge by now and why wouldn't it show up when it came out of the kiln? What process would cause it to turn unless there were some other chemical involved? Now this might make sense to me, say they used a gas to "turn" it this way or that and it had some effect that became apparent in later years.

They use a similar process to ship bananas. I believe they ship them green and gas them just before sale to ripen, or I've got it backwards, they use it to retard ripening.

To me, I think that walnut benefits from a penetrating oil type finish, one that lets the wood breath and does not apply a film. Even though I know there are old pieces of furniture with thick finishes that are still beautiful today. Of course, just because the wood is dark to begin with does not mean it can't be stained as well. Maybe your grandfather used a darker oil stain?

Anyway, maybe others will chime it. I did not take the time to do a lot of research here on your question, the answer may come from others.

All the best, Don

[JasonB]

Jason
Just curious as the the type of finish your Grandpa used on the crib?

you know, I'm not to sure, I'm thinking some kind of varnish or shelac, probably varnish.