Dark spots on maple

[David Justice]

I work with QSWO almost exclusively, but the wife wanted the bookshelf that is in the latest Fine Woodworking. I am using Saplele and Maple. I have the Maple milled and dimensioned, but the Maple has these dark places, they look like shadows that run across the boards like bands(pic attached). Can anyone tell me what these are, and more importantly, how to get rid of them.

Thanks for any help!374547

[Peter Christensen]

I think the staining is from the sticking when dried in a kiln or air drying. They may plane out depending how much of the surface you remove.

[Art Mann]

..........

[Mel Fulks]

If you ask before you buy, some say they use sticks that won't do that. Maybe plastic ...can't remember

[David Justice]

Well, that's not good, these are milled to thickness and planed as much as they can be. The plan was to only topcoat these, but I may have to rethink that to hide this.

[Peter Christensen]

If you have some offcuts you can try bleaching the wood. Oxalic acid or the stuff used on boats to clean teak. Take the needed safety precautions when using.

[Jim Becker]

I agree...it looks like sticker-stain and is apparently pretty deep. Peter's suggestion to bleach may help, but it's not assured.

[Jim Morgan]

I recently had some rough soft maple with similar symptoms, except that in addition to larger areas of staining, there were also several small stain spots. That made me think that it was a fungal infestation rather than/in addition to sticker staining. FWIW, it did plane out.

[Lloyd McKinlay]

Everything you want to know about sticker stain except how to cover it up. https://forestandwildlifeecology.triforce.cals.wisc.edu/wp-content/uploads/sites/111/2017/07/64.pdf

[Don Jarvie]

It looks like it’s soft maple and not hard. Soft maple has brown in it and looks like there is more brown around the knots compare to hard maple.

[David Justice]

It is definitely hard maple. It looks quite a bit lighter in person. I am pretty disappointed about this. I am very lucky that I have 2 very large hardwood dealers within about 20 minutes of me and I frequent one more than the other for no particular reason. I bought this maple from the one I don't go to very much. Not even sure why I did go there this time. i'm not a fan of maple, but I didn't pic the species for this project. I may try the bleaching.

[John K Jordan]

It is definitely hard maple. It looks quite a bit lighter in person. I am pretty disappointed about this. I am very lucky that I have 2 very large hardwood dealers within about 20 minutes of me and I frequent one more than the other for no particular reason. I bought this maple from the one I don't go to very much. Not even sure why I did go there this time. i'm not a fan of maple, but I didn't pic the species for this project. I may try the bleaching.

It looks like they may have stacked using boards instead of the normal stickers which should be no wider than 1.5" supposedly much worse for creating sticker stain (I use 1x1 stickers with my little sawmill).

Dr Gene Wengert on Woodweb says this about bleaching stain:

From contributor J:...is there any way to reduce the visual damage? I have 700 board feet of curly maple with this problem.

From Professor Gene Wengert, forum technical advisor:
The chemical stain can be bleached with wood bleach (oxalic acid).
...
Wood bleach will affect only the surface (perhaps 1/100" deep). Follow the instructions on the can, etc. After use, the surface must be washed or neutralized... follow the instructions. The finishing forum moderator here may have more information for you. We used to bleach frequently "in the old days," but I do not see it much today.

You can search woodweb for more about sticker stain

Maybe the lumber yard will exchange it since it is a defect. I understand you normally can't tell if sticker stain is present until it is planed so if you bought it rough sawn they might not have known.

JKJ

[Harold Balzonia]

Just paint it....








that was a joke....

[Lee Schierer]

Maple will also stain if it comes in contact with iron when wet.

[Peter Christensen]

It’s quite possible that those boards were between piles or at the bottom of the pile sitting on 4x4s or similar boards so a forklift can get under. Or the pile was banded over boards for shipping and some moisture got on it. When I buy from a lift I try to pick the second layer down if allowed for those reasons.

[Ted Phillips]

On a positive note, I got a really good deal on some sticker-stained cherry from a local hardwood dealer last year - got it about half price and I just worked around the stained parts. To my relief, an oil-varnish darkened the cherry significantly and hid the remaining shadows.

[Danny Hamsley]

Sticker stain is chemical. It is an enzymatic oxidation reaction with the sugars in the wood that occurs when the temp and humidity are high. That is why it is imperative to have high air flow around and through the drying stack when drying green maple. It only takes a short amount of time, sometimes a day or two at high temp and humidity and no to low air flow for the reaction to occur. Most times when I see it, it does not always plane out.

It can also occur not associated with the stickers themselves. This chemical reaction turns the wood a gray color, and can be either very unsightly or very pretty depending on the wood and what you are making. Here is a pic of some of the more ugly gray stain in some drawer sides.374709