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Started by Baron, June 07, 2017, 10:49:09 AM

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Baron

I have a small, small urban lumber business and I've actually built one of those famous VA tech kilns. While it works very well I don't have any sales right now. Most of my lumber is well air-dried and ready for the kiln.
-Is there any benefit to kiln drying lumber that is just going back into the drying shed when it comes out of the kiln.
-Doesn't it just take up the moisture again?
-And if it does take up moisture again was there still a considerable benefit to it having been kiln dried?
-If it does take up moisture may I still advertise it as kiln dried?

Certainly there is allot of changes in the lumber once it is kiln dry. There is shrinkage and bending and other forces at work as the lumber is gently brought down to 6 or 7% MC. If the lumber takes on moisture again after drying do this forces reverse?

Recently I've been wondering if Kiln Drying is only worthwhile if it goes from the kiln directly to a climate controlled storage facility until it is sold.
Sold or not should I dry it anyway!
Please comment!

GeneWengert-WoodDoc

You will have better sales if you can deliver the lumber promptly and not wait for kiln drying.  Carry and air dried inventory, in other words.

After kiln drying, you can wrap a bundle with plastic, like Saran which you can get in a large roll from Sam's etc.  you can safely store it for a year or more if it is covered on all six sides.  You could get a leak-proof trailer to store the wood, painting it black and supplying a small amount of heat.

Using the same shed for air dried and kiln dried does present an increased Rick of insects.  Wrapping almost eliminates the risk.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

ChugiakTinkerer

Additional benefit of kiln drying, assuming the right temperature is reached, are the setting of pitch and extermination of insects.  Depending on the wood and local environment those could be helpful in marketing your lumber.  Like Gene mentions though, you don't want to store kiln-dried with air-dried, as insects might get back in.
Woodland Mills HM130

Denny

This might be obvious, might not, but de-sticker the lumber and 'dead-pile' it when it comes out of the kiln. We always plane our lumber before we dead-pile it. Dead-pile meaning restack the lumber without the stickers. 

I've found that RO + WO can sit in 'dry storage' for many months without picking up much MC, and the opposite is the case for poplar and soft maple as their MC will start to slowly rise to your regions EMC soon after its left the kiln.  My dry storage building is monitored for temps and RH but the dang doors are open more than they're shut so my lumber will pick up MC eventually.

Baron

Hello Members,
Currently my two year old air-dried is at 6-10% and it will go into a trailer for the winter soon, dead stacked. I see how wrapping in plastic will prolong the lower MC.
I have some red oak and Honey Locust that has PPB. Is there any way to heat it in the solar kiln.
Is there a better way to kill these bugs?
Does Bora Care really work post-infection? One member was suggesting that it cost about $.05 per square foot not bad.

Baron

GeneWengert-WoodDoc

Bora Care is in water and must soak the wood well throughout, not just a surface treatment.  So, then it must be redried.

So, heat is the only option and a solar kiln will not be hot enough to get the interior of the wood to 133 F.

How do you know you have PPB?  It would be rare in locust.  It also takes perhaps a year to show up, so is this wood a year old since it was dried to under 20% MC?  Do you see new holes?  The holes you see forming now are exit holes, so the pregnant beetles will be infecting other lumber nearby, but you won't know for a year or so.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Baron

Hello Gene,
While it would be rare in Robinia it doesn't seem to be so rare in Gleditsia T., true honey locust. .  I only use Urban trees in my operation so Gleditsia, Zelbova, A. Platinoides, and Dawn Redwood are starting to become more common as they are reaching maturity in the home landscape environment. My training was insect and disease control of woodies earlier in life. Your right on the money when you mention the timing as one year after storage. It seems that the PPB (not well versed enough to know which var.) is on its third year now where it is stored in my trailers. Only the sapwood is infected. The locust probably got it from the Hickory that is was stored next to.

Why can't I just stick a baseboard heat strip across for 12' above the doors and below the vents and heat the wood up to 135 (internal stack temp). What would it take, two days, to be sure? I had a chance to have lunch with Brian Bond and he said "know way, it can't be done". "Sounds like a challenge to me" I said :-)

With the Bora Care I guess that only the trough-type soaking would get it wet enough or would drenching with a backpack be enough? This seems to only be practical for new wood in which case Timbor may work as well but less expensively?

Thoughts?


GeneWengert-WoodDoc

You indeed have the correct idea.  A household strip heater will not get hot enough, however.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

WDH

With the chemical, you have to hope that it penetrates enough to kill the larvae and eggs.  With the heat, there will be no question. 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

YellowHammer

To heat up a solar kiln, you will need some safe BTU's, but how much heat input would be dependent on how well the kiln is insulated.  I have never tried to sterilize in my solar kiln, as it leaks too much, but I have had very good success using multiple 500 W sealed halogen work lights, mounted in front of kiln fans to keep them from overheating, in one of my other, well insulated, DH kiln.  2,000W to 3,000W should be a good start for a somewhat sealed, if not overly insulated 750 bdft solar kiln in summer, and it's typical for me to to have a 12 hour rise time to 150°F, then hold for 24 hours, then vent and slowly cool down for 24 hours. 
The wood will be sterilized, and you should visually inspect and see lots of dead insects in top of the boards. 
Before I spent the money on the electricity, I would go around and make sure I had a good, airtight, insulted space.  Put duct tape over the vents to seal them.   
YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

Baron

YellowHammer, I never thought of using light bulbs. We used them to keep the milk house from freezing on cold nights when I was a kid in the 60's. I will give that some thought. I do have some calibrated thermometers that i insert into the stack at different points to tell me the actual temp in the stack. The highest it gets in summer is 128 daytime, summer and 60's winter. The wood dries very safely and and nicely and cools at night. The fans are straight solar. The kiln is well insulated and I was thinking it would make a nice heat chamber. The only uninsulated part of the kiln is the Glass. If I used the heavy concrete blankets over the glass it would be a nicely insulated. The fans are all metal and could be run by a 12v inverter along with some heat source.

I'd like to hear more successful cases of Bora Care use.

How do you know when the pitch is set. I have very little conifer come through my supply chain and I only air dry it.

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