Slowing Down Wood Drying
Once wood starts to dry, it's hard to slow the process down without encountering staining or rot problems. December 6, 2009
Question
I have basswood cants (9/4) that I re-saw into 1/8" - 1/4" pieces for a customer. The customer wants the pieces to have a 25% - 30% MC when they receive it however I only supply them so many pieces as needed on a weekly basis. I picked up the cants a few months ago - stacked and stickered with ends coated and is outside tarped. The wood is drying faster than the order is being filled and is already down to about 30%. Any recommendations on how to slow down the drying? What problems might occur if the lumber is stacked tight together? Would it be better to be inside a shelter tarped?
Forum Responses
(Sawing and Drying Forum)
From contributor Z:
The wood's drying rate is going to depend on:
1. Air flow
2. Temp
3. Relative Humidity
Playing around with one of the above or all three can change drying rates. Can also cause staining and fungus growth.
Could try:
1. Thinner stickers
2. Stacking lumber in an unheated indoor closed off to most of the outdoor wind.
3. As you suggested, covering with a loose fitting tarp will increase the RH in the lumber area.
I'd try thinner stickers first. Monitor wood closely as degrade could happen. Good luck and let us know what worked for you.
From Gene Wengert, forum technical advisor:
I would be tempted to saw them all and then store them, wrapped in plastic, in a freezer until your customer needs them. Otherwise, you will have mold, stain, and other issues as the weather warms up and may be stuck with partly dried, stained pieces that you cannot sell. I have heard that sometimes the wood is wrapped with a few moth balls to help eliminate fungal stains, but i do not know if this works or not.
From the original questioner:
Yes, I did replace the 3/4" stickers with 7/16" and pulled them tight together, and would like to bring the wood inside but I'm limited on space. I do like Gene's idea of sawing it all up at once, wrapping and freezing the pieces. Does basswood stain much or at all? If the wood stains only slightly and not a dark staining, it may not be a big issue. Only the thickness side will be visible.
From Gene Wengert, forum technical advisor:
Basswood does indeed stain quite a bit. It’s a blue stain, so it is obvious.
From contributor S:
You might be able to rent some freezer space if there are any meat packing outfits nearby, this will also raise your cost. Basswood isn't a high dollar wood so maybe just cut your losses and try not to buy more than you can use next time.
From contributor G:
What about watering (set up a continuous sprinkler system) them? If you collected the runoff you could reuse the water. They wouldn't dry out and evaporation would help keep them cool. If the volume wasn't too great you could also band them together and submerse them in a tank or pond. Basswood floats.
From Gene Wengert, forum technical advisor:
In most cases, the technique described by contributor G will develop a lot of mold and staining (fungal and chemical) in basswood.
From contributor Z:
Gene, what if Silvanus sprayed the faces (top and bottom of boards) and the end grain of the lumber with something like AnchorSeal. I would think you would not get sticker stain and would reduce drying way down? Or, would you get internal staining?
From Gene Wengert, forum technical advisor:
Good idea, but you will get chemical staining (gray and pink in basswood) and also any fungi that are on the surface will have a chance of becoming active.
From contributor G:
The hardwood industry routinely waters logs to reduce degrade during extended storage. In addition to reducing checking, water deprives fungi and microbes of oxygen which is how/why staining is prevented. This is also how/why logs that were submerged a century ago can be excavated and sawn to yield good lumber. Sure there will be some surface degrade but what the poster is after is a way to prevent losing all of the wood.
From Gene Wengert, forum technical advisor:
To contributor G: with logs, especially those with a lot of heartwood, we can sprinkle or submerge them. The sapwood is often deteriorated. However, with lumber, as each piece has already been exposed to air and a little surface loss can be substantial, it will not work the same way that it works for logs.
From the original questioner:
What is AchorSeal? What if I spray all surfaces with a linseed oil solution to slow down drying and then spray a 50/50 bleach mix or some other anti-fungus solution to prevent bacteria? By the way, if the wood does stain (again, if its moderate it won’t pose a problem) can it be erased or reduced with bleaching or something else? I appreciate everyone’s input!
From contributor S:
I think you can go out and buy FAS basswood for less money and hassle than all the treatments discussed.
From Gene Wengert, forum technical advisor:
AnchorSeal is a commercial end coating product made by UC Coatings in Buffalo, NY. They advertise here, so look on the right side of the screen. Linseed oil will not slow drying much at all.
Bleach will kill existing fungi, but it will not work for future infestations. Further, it will not get any fungi that are already below the surface. Bleach will not affect chemical stains that occur inside. Bleach will bleach the surface and make it quite uniform and white, which may an issue for the user. I do not know if any residuals will affect subsequent processing (dust safety, finish quality, etc.). Very few stains can be erased easily, if at all.
