Wood Drying Techniques

[carbonsteel928]

After seeing quite a few posts asking for advice on processing burls and raw wood, I’ve decided to weigh in with my experience.
At the height of my custom brush and pen turning I was going through about a hundred pounds of wood per month, which isn't much in comparison to bowl turners or even some of the more prolific knife makers but it did impart some lessons upon me.
The first thing one must do when considering processing raw wood into scales and blocks is realize that there is much waste involved as there are no guarantees to how much of your raw material will survive. We have to take special care to avoid careless waste which can be prevented with minimum effort.

1. Purchase a moisture meter to determine MC% (moisture content). Not the best, but this one will fill our needs: http://www.woodcraft.com/PRODUCT/20...ode=10INGOPB&gclid=CKarwJPD-rgCFSdp7AodtD0A8g

2. Understand the species with which you are working. Madrone burl will react differently than Mesquite, or Amboyna. From what I have noticed, the higher the initial moisture content, the greater the chance for checks, cracks, splits and honeycombing. Species that are prone to quick moisture changes benefit from boiling (will be discussed shortly).

3. Be patient. Though there are techniques that can be employed to lessen drying time, few of them, if any, will give you the same positive results that proper seasoning will.

There are many techniques to hasten the drying process and some are necessary for processing certain species that are prone to movement. Below is a quick list of the more effective:

1. Boiling some species, such as the aforementioned Madrone burl, can shorten its drying time as well as increase its yield by helping prevent honeycombing.
I. Cut blocks of wood down to a manageable size ( If I’m aiming for 1 ½ x 1 ½ x 5 blocks, I prefer to cut a larger block at about 2 x 6 x 6 which will later be cut down to working size)
II. Place blocks inside a stock pot with cold water and bring to a boil
III. Allow blocks to boil for at least 2 hours
IV. If the wood is prone to movement, after boiling for two hours, allow to cool in pot over night. If the wood is not prone to movement, you can remove the block after two hours.
V. Once the blocks are removed from the water, wrap completely in newspaper or place inside paper grocery bag and store in a cool dry place (use sticker if staking them).

Boiling should cut your dry time down to about 2 months depending on the size of the block. Boiling can be done with any species of wood but it isn’t necessary unless dealing with the likes of Manzanita Burl or Madrone Burl.

2. Kitty litter

I. Place kitty litter in bag or box
II. Place blocks of wood into kitty litter and cover
III. Check MC% every week or so until you’re down to sub 10%
IV. Remove blocks from kitty litter once the proper MC% has been reached.

The kitty litter method will work quickly, about 4 weeks for large blocks 1 ¾ x 1 ¾ x 6 so use it only on woods that are naturally stable such as Mesquite, Osage Orange, Persimmons, etc. Kitty
litter can be reused after dehydrating in an oven.

3. Hot Box

I. Find or make a box (rectangular or square)
II. Place 60-100w light bulb(s) (one for every 12” of length)
III. Cut an opening at one end of the box (you will be inserting a fan so cut it accordingly)
IV. Place fan at the opening that you created
V. Place a thermometer to gauge temperature

The hot box isn't as easy as the others but if you have even the slightest knowledge and ability to work with electricity, you will be able to approximate a kiln.

If you choose to stick to traditional seasoning methods. Remember to seal the end grain of your blocks. For this you can use latex paint, paraffin or Anchorseal (optimal). You can also wrap them in newspaper or bag them to slow down their loss of moisture. Hopefully this keeps you guys from having to wait months or years for a whole burl to dry enough to process. Most woods can be processed green (always cut oversized) if handled correctly afterwards. Remember that depending on species, your safe rate while drying should be from 1 to 4.5%. Denser/ oilier woods will dry at a slower rate whereas everything else will dry a bit faster.

With any luck this isn't too garbled to decipher. I hope it helps.

Regards,
Mike

 

[Willie71]

Thank you for the summary. I never tried the boiling method, and will.

 

[Shawn Hatcher]

This is wonderful info, Mike. Thank you so much for sharing your insight and experience with us! :thumbup:

 

[Tom Lewis]

Thanks for the information. In addition, some soak the wood in alcohol, some soak in soapy water, some microwave the wood.
I have tried most of the above methods, and what works best for me is to cut the wood oversize, preferably in winter, then coat the blocks with a wax emulsion, one type is called anchorseal. It can be purchased at most woodworking supply stores.
I keep an eye on the wood as it is drying and if any cracks start I fill with superglue.

 

[carbonsteel928]

Thanks for the information. In addition, some soak the wood in alcohol, some soak in soapy water, some microwave the wood.
I have tried most of the above methods, and what works best for me is to cut the wood oversize, preferably in winter, then coat the blocks with a wax emulsion, one type is called anchorseal. It can be purchased at most woodworking supply stores.
I keep an eye on the wood as it is drying and if any cracks start I fill with superglue.

Thank you for mentioning that Mr. Lewis. I've tried soapy water and it works well but it does interfere with the stabilizing process. I have some wood that didn't do well with a few of the top dog stabilizers and when trying to find the solution, it came down to soapy water. Denatured Alcohol works great too but the problem with it is cost and flammability. The microwave is tricky too, I've set a few fires fine-tuning my method and ruined a microwave in the process. Once you microwave wood, it emits a smell that tends to hang around in your appliance.

 

[Burl Source]

With madrone burl I tried something that Chuck from Alpha told me.
He said to cut a bit oversize, wrap in plastic and then stash in the shed for a couple years.
Madrone is notorious for moving all over the place and tearing itself apart when drying.

I had a couple 50lb chunks that I wrapped in pallet wrap and put in the wood shed.
3 or 4 years later I found them and decided to cut one into handle blocks.
The wood was still soaking wet. The piece developed unusual colors and had not cracked at all.
The oversized handle blocks went into a drying room with fans and a dehumidifier.
2 or 3 weeks later they were dry with no cracking and barely any movement.
I think holding the moisture in for a few years changed the structure of the wood so it could dry without cracking.

 

[Tom Lewis]

The suggestion to wrap the wood in plastic is a good one. Some good ideas in this thread.
One wood that really is hard to cure is algerita (It grows in the NM desert). I cut some blocks, painted them with varnish, then wrapped in wax paper. After a few years the wood was cured with no cracking.
One thing I forgot to mention is, if possible cut the pith out of the wood. Wood tends to crack from the pith, (center) out so if the pith is removed the wood is less likely to crack.