Experiences on slab storage

[pezrock]

Hello all, tell me your experience on the following:

1. At what point can I store a slab standing upright instead of stacked and stickered?

2. At what point do air dried slabs 1 1/2" to 2 1/2" generally reach about 75% stability in the northeast? I know wood will always move a little introduced to new environments and this question is difficult, but lets say I wanted to sell a slab for a bench and any new movement would be relatively unnoticeable. 

3. How much does removing the bark aid in the drying process? 

4. How hard should I crank down on ratchet straps to attempt keeping boards flat?

5. How do I know the difference between cellular moisture and regular moisture? 

6. At what point can I be confident that my anchor sealed 2" to 4" cookies (maple, ash, red cedar, walnut) have stopped moving and will no longer crack? 

My goal is to sell air dried slabs. I have customers wanting slabs that I know have at least 16% to 19% moisture on my cheap pin meter but they want them anyway. I tell them they are still not fully dry and they need to acclimate before using and it could take a while depending what they are using it for. Maybe because I am selling discounted or they have the patience to wait, generally they are not deterred. This business is mostly a hobby that I support with small sales. I'd just like to be more informed so I can pass on to any potential customer. If there is anyone else like me reading this feel free to chime in, especially with answers to questions that I didn't ask.  



 

[metalspinner]

T1. As long as possible. I know it's tough to see the slab and know what you have on stickers. But storing them on sticks is the best, IMO. 

2. Weight is a good, measurable metric. Kind of a pain, though. When the wood stops loosing water weight, it's done what it's done in that environment. 

3. I've never liked the look of bark on a finished piece of wood, so I'll take it off during or just after sawing. Or anywhere along the way when it wants to come off. Bark
Is messy, unreliable, and a haven for bugs. 
4. As hard as possible. 

5. The free water releases first. The bound water much later. That's a very general statement. The experts can get specific. 

6. Confident?? Never!

If you believe your customers are not really understanding the drying related issues, maybe give them a one page document explaining basic wood moisture issues. Ending with a "proceed at your own risk," clause. 

[cutterboy]

All of those questions are difficult to answer because there are many variables.
 I also sell air dried slabs mostly 2". I stack and sticker them and leave them for a year. At that point I put them up for sale and stand some of them up to better display them. I have never had any customer who bought one come back and complain about it.

Good luck to you.

[firefighter ontheside]

A rule of thumb I've heard is one year per inch of thickness for air drying.  It's just that, a rule of thumb, but it has some merit.  I would think in the northeast, your slabs may get down to about 12% at best with air drying.  Cheap meters are not accurate usually, but they are usually good enough to track progress.  If your slabs stop showing any drying, then they are probably as dry as they are going to get.  Seasons of the year have to be considered too.  The humidity of summer can slow or stop the drying after a certain point.  I built a shed and use it as my kiln with a dehumidifier and fans to remove moisture.  I can get wood down to about 7% in about a month after it has air dried to 20% or less.

[longtime lurker]

Free water is the water between cells. Generally that will be moisture content above 20%. Free water runs out fast, usually within 4-6 weeks of sawing if the timber is on stickers with adequate ventilation.
Bound water is the water within the cells themselves, and is what's left below 20% MC  As mentioned above an inch a year is the old rule of thumb for air drying, but results can vary depending on thickness, species, and environmental conditions.

All wood moves and keeps moving, for that is the nature of wood. But generally you want it within a couple of percentage points of target for best results.

Get rid of the bark as early as possible. It's messy and a haven for insects and fungal organisms.

Give every slab a serial number and take lots of pictures, that way you can show customers your inventory by email and not need to stand anything up for display purposes, until the client is inbound with a first full of moolah.

[WV Sawmiller]

   If you are having trouble selling a slab put it on the bottom of the stack because the customer always wants the one on the bottom. ;D Displaying them is the biggest problem I have so I'll be watching this thread for new ideas. Good luck.

[WDH]

I store mine vertically in a climate controlled room.  However, mine are kiln dried to 8%, sterilized, flattened, and planed.  I do not sell air dried slabs because my customer base wants them ready to use.  Kiln drying, sterilizing, flattening, and planing are significant value added steps and increase the slab value substantially.  Storing vertically makes it much easier for one person to move/sort through them as they can be "walked" versus lifted and carried. 

While everyone cannot plane and store in a climate controlled space, I believe air dried slabs still need protected storage.  One issue here in Georgia, and it is a major issue, is powderpost beetle infestation.  I do not sell unsterilized slabs because of a bad experience with a kitchen island top that I made for a customer with unsterilized white oak.  Three years later she called me and said there were little piles of sawdust on her island top and asked me did I know what was causing it.  Well, I did know . 

 At a minimum here, slabs have to be sprayed with disodium octaborate tetrahydrate green off the sawmill or you will be selling powderpost beetles with your slabs a number of times and very bad things can happen to you if an unsuspecting customer decides to hold you accountable. 

https://forestryforum.com/gallery/displayimage.php?pid=257834

https://forestryforum.com/gallery/displayimage.php?pid=257835

[pezrock]

All of those questions are difficult to answer because there are many variables.
I also sell air dried slabs mostly 2". I stack and sticker them and leave them for a year. At that point I put them up for sale and stand some of them up to better display them. I have never had any customer who bought one come back and complain about it.

Good luck to you.

It was at about the 1 year mark when I was feeling more comfortable about selling inventory. Do you know what the moisture percentage range reads on your boards at that point? I know species and width are also factors, but maybe pick 3 of your top sellers. We have a similar climate. 

[pezrock]

I store mine vertically in a climate controlled room.  However, mine are kiln dried to 8%, sterilized, flattened, and planed.  I do not sell air dried slabs because my customer base wants them ready to use.  Kiln drying, sterilizing, flattening, and planing are significant value added steps and increase the slab value substantially.  Storing vertically makes it much easier for one person to move/sort through them as they can be "walked" versus lifted and carried.

While everyone cannot plane and store in a climate controlled space, I believe air dried slabs still need protected storage.  One issue here in Georgia, and it is a major issue, is powderpost beetle infestation.  I do not sell unsterilized slabs because of a bad experience with a kitchen island top that I made for a customer with unsterilized white oak.  Three years later she called me and said there were little piles of sawdust on her island top and asked me did I know what was causing it.  Well, I did know .

At a minimum here, slabs have to be sprayed with disodium octaborate tetrahydrate green off the sawmill or you will be selling powderpost beetles with your slabs a number of times and very bad things can happen to you if an unsuspecting customer decides to hold you accountable.

https://forestryforum.com/gallery/displayimage.php?pid=257834

https://forestryforum.com/gallery/displayimage.php?pid=257835

Thanks for replying.
Can I apply this just prior to selling the board and it still be effective? 
What is the coverage rate? 

[WDH]

No.  You have to spray immediately, after sawing.  The beetles lay eggs on the surface of the slab.  The larvae are very small. Once the egg hatches, the larvae enters the wood via the pores and there will be no exterior evidence that they are even there.  They can stay in the wood for several years or more before they emerge as adults and seek out more wood to infest or even re-infest that very same slab.  The spray penetrates the surface of the wood and when the larvae hatch and try to worm their way into the wood, the borate kills them. 

Spray the slabs until totally wet on all 4 sides.  If you have not sealed the ends with anchorseal or some other sealer, spray the ends too. 

[metalspinner]

WDH
Where can one buy this spray? We have a local Co-Op farm
Store. I wonder if they have it?

[moodnacreek]

To really get into air dried 'slabs' you need a flat sturdy surface to stack [stickered]  the planks on. Concentrate on sawing as many as you can and stacking as high as possible. Also the end sticks should be wide and overhang the planks. The more weight on top the better as you can never have enough. 3 years will go by faster than you think and the ones on the bottom can be stood up indoors. Many will be cracked, cupped or twisted and must be re sawn and or shortened. Consider doing pine and cedar as they will dry much sooner. Again do a lot of them and charge all you can get for the best ones to cover your losses.

[WDH]

The good thing about pine and cedar is that the lyctid powderpost beetle does not infest them, just hardwoods.  

Disodium octaborate tetrahydrate (DOT) is 20.5% boron.  It is a borate salt.  The formulation is 98% DOT plus some inert stuff.  There are several sources.  One, Timbor, is labeled for insecticide use.  Another is Solubor which is used as an additive to supply the micronutrient boron in liquid fertilizer.  Both are exactly the same.  98% DOT.  Just the label and color of the bag is different.  Read the labels.  It is exactly the same chemical.   You can buy Timbor and pay 2 times as much for it as you will for solubor.  

Here is what I tell customers.  "I spray my lumber with 98% disodium octaborate tetrahydrate.  One brand name is Timbor.  If you could like, you can look it up and read the label."  I buy DOT in bulk in 50 pound bags for about $80 a bag or $1.60 per pound.  You can buy a 25 pound bucket of Timbor for $96 not including shipping for $3.85 per pound.  You would need to get solubor from an AG fertilizer and Seed company that supplies farmers.  A preventative solution of DOT is one pound dissolved in a gallon of water.  It mixes best with warm or even better with hot water.  I mix mine in 5 gallon buckets with just regular tap/well water a day ahead.  This gives the powder enough time to fully hydrate and dissolve. I do not have a source of hot water at the sawmill.

I use a 25 gallon ATV spray tank with diaphragm pump powered by a battery pack/jump starter.  The tank has a long hose with a spray wand.  A pump-up hand sprayer is way too hard to use, way too small for the volume that I do. I stack the slabs coming off the sawmill on a purpose built table in one stack, one slab stacked on top of the other.  Then I can spray all the edges on both sides of the slabs at once. Then they are spread out on the table to spray one face, flipped, and the other face is sprayed.  Then they are stickered on a pallet.

Even if you do not sterilize the slabs in a kiln, the DOT will prevent any insect infestation and you can sell your air dried slabs all day long worry free.

Here is pic of spray table with freshly sprayed pecan (  ) slabs.

https://forestryforum.com/gallery/displayimage.php?pid=186200

[Don P]

What he said. I'm going through a couple of bags of another brand but chemically the same, DOT in a wettable powder. Just make sure it is not the time release granules. I think we have 3 pump up sprayers rattling around in the trucks right now, definitely slower than the bigger electric spray rig but much easier to walk around with. The last I sprayed we were sawing at the edge of the woods out on site, mixing with water out of a barrel and straining into the sprayer through an old T shirt, just as a by the by on how crude it can be.

For us and the volume that moves, slabs are a waste of real estate but they are not my focus. They do not stack well or neatly and get sorted, picked and restacked multiple times per sale. There is a stack of boring oak slabs that might just get resawed into framing if they pinch the pathway one more time, that would be an awful lot of wasted time and labor but beats being an overstuffed wood hoarders museum.

Take a fresh cut of some partially seasoned firewood or boards. Look at the fresh end, you will see a dry looking "shell" and a wet looking core. That is the difference in free and bound water, or, the point above and below the fiber saturation point. When you can see the moisture, what you are seeing is "free water" the loose, liquid water inside the hollow cavity, the lumen, of the cell. When that water dries out (easily) what is left is the moisture bound up in the fibers of the cell wall itself. That is not visible to the eye and is the range from about 20-30% and equilibrium moisture content, when the wood is acclimated to its surrounding relative humidity. That water bound to the cell walls is what causes shrinking and swelling as it occupies space within and between the fibers of the cell wall.

Into the weeds :D. Borate diffuses inward through the wood on the free water, the salt travels by diffusion moving through the water from the surface at high salt concentration into the low concentration free water in the cells, the wood has to be thoroughly saturated inside and out to get good penetration. There's where you use free water to your benefit to get maximum penetration. Goint the other way it doesn't really leave until that same fiber saturation and concentration difference happens.

[WDH]

Which means the salt will leach back out if the slabs are not protected from the rain/elements/rewetting.  

[Old Greenhorn]

Me too also on what Don and WDH said. They both (with others) walked me through this last year. One point I would stress is DON"T use cold water for the mix. I did this on my first batch and the stuff precipitated out fairly quickly and never really did mix. The next batch I used hot water from the woodstove and it was a world of difference, there is a still a little left after a few months of not milling and it has yet to separate.

[metalspinner]

"  but beats being an overstuffed wood hoarders museum."

Hey! I resemble that remark!

[cutterboy]

Pezrock, My lumber air dries down to 10-12%. That is my 4/4 lumber. My 2" slabs are 10-12% on the outside but I don't know what it is on the inside.

[BenTN]

WDH
Where can one buy this spray? We have a local Co-Op farm
Store. I wonder if they have it?

There is a Timbor plant right here in Rockford. I'm not sure if they sell retail from there tho