Minimizing Sticker Stain

An explanation of what causes sticker stain, and how it might be prevented. July 30, 2007

Question
It is my understanding that composite and/or "breeze-dri" type stickers will help minimize sticker stain but not guarantee total elimination of it. Is this correct? Also, has anyone ever heard of bleaching wood stickers to eliminate sticker stain?

Forum Responses
From Professor Gene Wengert, forum technical advisor:
Sticker stain is caused by the oxidation of sugars in the wood being dried. There is nothing from the stickers that gets into the wood; rather, the stickers slow down the drying rate where they touch the wood, and are able to allow the reaction to proceed better than in areas where drying is rapid.

So with that understanding, composite stickers themselves will not help sticker stain. Breeze dried stickers will help as they allow for faster drying. Bleaching is not going to work for the reasons stated.

However, poor treatment of the lumber including a bad kiln schedule or bad kiln RH or air flow or temperature can cause stain no matter what sticker is used.

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From contributor D:
I am not sure what breeze-dri stickers are. I dry a lot of white wood (poplar, maple, etc.) using fluted hardwood stickers. Switching from solid to fluted sticks greatly lessoned the problem, but I have still had some sticker stain on a couple loads when the sticks had gotten wet before I used them.

I don't know if bleaching sticks would help. Sticker stain is caused by the different drying rates of the exposed wood compared to the unexposed wood under the sticks.

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From contributor D:
Gene was typing a response at the same time as I was. He explained it better than me.

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From contributor B:
Breeze Dried stickers are a patented design that has a series of flutes angled across the surface, to minimize the wood-to-sticker contact and allow for better air flow across the wood surface.

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From contributor N:
We use fluted stickers that we have made. They seem to work very well. We probably saw 50% pine and we like to use them on pine to minimize the growth of blue stain. On hardwoods, we've found (learned from kiln dry classes) that the best thing you can do is immediately stack the lumber after sawing. Randomly place the stickers. Then, within 2-3 weeks, restack the lumber the way you normally would (we use a 2' sticker spacing). What you have done is allowed the surface to get some air drying on it. Restacking (and good to use new or different stickers if you can) changes the location of the sticks on the lumber for the finish stacking and greatly helps to minimize sticker stain. The prime wood we do this on is maple, but it will certainly work on any other species that might be giving you trouble. Our choice for stickers is yellow poplar (tulip) since they are more durable and won't crush like pine ones will when your piles are stacked 10-12 feet high.