Kiln drying question

[Darius Ferlas]

I am somewhat ignorant on the details of the kiln drying process so I would request information/suggestions.

I received an offer of free cherry lumber, roughly 400+ bf, that is still in the form of logs, so the wood is very green. I have some options as far as the milling dimensions do and I am tempted to ask for 8/4. I could try and wait for the lumber to air dry but it seems that, considering the climate and other circumstances, I'd have to wait 3 to 5 years for the wood to be usable. Local kiln services that require a minimum of 1500 bf.

The other alternative I have is to ask a local friend of a friend to put the lumber through a pallet heating kiln. The process was described to me as steaming and drying for 8 to 10 hours at 65C (130+ F). According to this kiln's operator the lumber leaves the kiln at 16% MC. I could have it go through two or three cycles if needed.

Is this something I should consider or would that be asking for trouble?

Thank you for all the suggestions.

[Frank Drew]

Darius,

The disadvantages of air drying are the time spent on set up (flat, stable foundation in an appropriate location out of the direct sun but with some air movement; stickering; etc.) and time waiting for the wood to dry. But with a bit of luck, if you started out with a good log that was sawn carefully, you can end up with excellent dry material, with very little up front expense. I've very much liked the air dried material I've used, and all things being equal might prefer it to kiln dried although I've certainly bought and used vastly more of the latter.

If you can find a kiln operator you trust, and if it won't cost you more than you feel comfortable with, there's no question that kiln drying will get you usable lumber much more quickly than waiting for air drying. Know, though, that some of the problems woodworkers have had with kiln-dried wood is due to the kiln operators pushing the wood through the drying process too quickly.

But before anything, you'll do yourself a favor by end-coating the logs ASAP, preferably with on of the proprietary green wood sealers (Anchorseal, et al.)

[george wilson]

If the kiln operator doesn't do the job right,you could end up with "case hardened" wood. This wood will warp like crazy after you resaw it.

Stacking the wood with stickers that are vertically IN LINE,under a tarp,with possibly some tar paper inside the tarp will be a safer way to go.

I can't remember the details of doing this. There was an article in FWW several months ago. You need to investigate how to do this right.

We cut 5,000 bd.ft. of beechwood in Williamsburg. But I just painted the ends with thick paint. We then stored it in the uninsulated attic of a historic garage in the museum. Nothing fancy. We occupied ourselves with other jobs while waiting for it to dry. 1 year per inch of thickness drying time. It got plenty hot in that attic.

We'd bring in beech from the garage,and let it acclimate in our shop for some months before we made planes(that were supposed to stay straight!) before using it.

[Frank Drew]

The other alternative I have is to ask a local friend of a friend to put the lumber through a pallet heating kiln.

Know, too, that the wood quality needs of the pallet industry bear no relation to the wood quality needs of the fine woodworking community. (Nothing against the friend of your friend, I'm just sayin' is all....)

[Darius Ferlas]

Thanks for the answers.

To further clarify, my cost for the lumber is a case of beer. The wood is still in form of a long log and the charges for the drying (as described) is $50.

I was considering the attic above my garage to air dry it but all things considered, it would be impossible to drag the boards up there. The dry and fairly well ventilated basement was another option but I would prefer to wait much less than air drying would take.

My tentative plan was to sticker it correctly and tie the bundle with ratchet action tied-downs. I will also seal the boards' ends (thank you for the suggestion).So the kiln/palette drying is the next best option I could think of but I'm not sure if I will do more harm than good to the lumber.

[Frank Drew]

My tentative plan was to sticker it correctly and tie the bundle with ratchet action tied-downs. I will also seal the boards' ends (thank you for the suggestion).So the kiln/palette drying is the next best option I could think of but I'm not sure if I will do more harm than good to the lumber.

Darius, it would be a lot easier, and better, to seal the log ends right now rather than wait to do the individual boards once they're sawn; as for sawing, if the log is of a decent size and you have a good sawyer, having it sawn through and through (flitch sawn) into a variety of thicknesses will give you the best widths and widest assortment of boards, although a lot of sawyers don't use that method.

And even if you plan on kiln drying, many like to air dry the boards for a few months before they go into the kiln. But however you go about it, sawing a log sooner rather than later is generally best.

[Faust M. Ruggiero]

Darius,
If the wood looks good, nice diameter straight logs with no apparent bug infestation, keep looking for a sawyer with a kiln. Forget the big commercial operations. Look for a little guy. 8/4 is the way to go if you can re-saw. The problem is you need one year per inch of good drying weather. Where I live in PA, we only get about half the year as drying weather. Once the relative humidity outside is the same or higher than the wood, drying takes a vacation. Call your local mills. I am sure someone knows someone.
fmr

[cody michael]

you could look into making your own kiln. i have all my lumber cut and dried by a local guy that would do 1 board if i asked. you just have to find them. i only knew because someone suggested him. maybe ask at woodworking stores. woodshop teachers ect.

[Scott T Smith]

I'm a kiln operator.

The air drying rate differs per species, thickness, grain pattern, and your climate conditions. Quartersawn typically takes longer to dry than plainsawn. Few woods require a year to dry 1" if they are milled at 5/4 in the South US in the springtime.

The pallet wood kiln will most likely damage your wood - don't use it. Furniture grade wood requires a specific schedule in order not to damage the wood.

8/4 Cherry has a maximum safe daily drying rate in a low temperature kiln of around 3.5% per day. Green, the wood will be around 60% MC, so at 3.4% per day you're looking at at least 15 days in the kiln.

The most critical time in the drying process is from green down to 35% MC. Dry the wood to quickly during this time, and you'll have some expensive firewood.

DO coat the ends of the logs with end sealer. If significant checking has already started, remove a few inches from the end of the log until you have clean wood (no checks), and then apply the end sealer. It's best to do this as quickly as possible after felling the tree and bucking the logs to length.

Your best option is to find someone local with a solar kiln. The most common design (based upon the Virginia Tech model) will hold around 1,200 bd ft. Depending upon where you reside (as well as the time of year), it will take probably 2 months in the kiln to go from green to <10%.

I'm a big fan of attic wood drying and storage, but AFTER the wood has dried from green below 25%, or potentially earlier during the winter.

With a targeted daily MC% reduction of 3.5% per day for your 8/4 cherry, you're most critical need for the first few weeks of air drying is not to dry the wood too quickly.

For maximum quality, log (and end seal) on day 1, mill on day 2, and get the wood into the kiln on day 3.

[Tony Bilello]

Green Cherry is a woodturners dream. There is nothing in the world like turning it. Continuous ribbons that travel 15 feet behind you, totally wet face shield, can be turned to almost a paper thin with sharp chisels.

If you want info on kilns and portable saw mills in your area etc. send me a private message and I wil give you a good contact. I don't like to openly give links to other similar sites. Not sure if it is considered improper or not.

[Loren Bengtson]

I was considering the attic above my garage to air dry it but all things considered, it would be impossible to drag the boards up there. The dry and fairly well ventilated basement was another option but I would prefer to wait much less than air drying would take.

My tentative plan was to sticker it correctly and tie the bundle with ratchet action tied-downs. I will also seal the boards' ends (thank you for the suggestion).So the kiln/palette drying is the next best option I could think of but I'm not sure if I will do more harm than good to the lumber.

Darius,

As Scott said, DO NOT use the pallet kiln. Drying your wood that fast will ruin it.

Ratchet action straps, or any other kind of straps will not prevent your lumber from warping as it dries. You need weight for that. The reason is that wood shrinks as it dries, so the straps loosen. If you put weight on top of your lumber stack it will prevent the lumber from bowing as it dries.

If this wood is as heavy as I expect it is, you may find that your ceiling will cave in if you put the wood in your attic. I would vote for the dry, well ventilated basement.

I do not have a kiln yet (expected by this time next year), but I dried 5/4 oak in my son-in-law's basement that isn't so well ventilated. In spite of that, the oak dried nicely in a reasonable time.

My guess would be that it might take a year for 4/4 cherry to dry in your basement, possibly two years for 8/4.

Here are two reference books that you can download:
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr118.pdf
and
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr117.pdf

There is a wealth of information in those.

Good luck,
Loren

[Frank Drew]

Drying large quantities of wood indoors without some means of getting rid of the moisture given off can lead to issues with mold, etc.

(Note that Loren dried his oak in his son-in-law's basement :D.)

[Loren Bengtson]

Drying large quantities of wood indoors without some means of getting rid of the moisture given off can lead to issues with mold, etc.

(Note that Loren dried his oak in his son-in-law's basement :D.)
Frank,

And, for full disclosure, the house wasn't finished yet. It was entirely enclosed, but no one lived in it.

That point about moisture is well taken, but Darius did say that the basement was dry and fairly well ventilated. If the ventilation is sufficient, it should take care of the moisture.

-- Loren