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Post Oakie
Post Oakie's picture
Air drying lumber

 

Whether you are milling for yourself or for a customer, you should make proper stacking a priority.  Many people who run portable sawmills skip this step and they and their customers wind up with expensive firewood.  Light colored woods, such as sycamore and maple will soon discolor, and decay and insect damage are possible for any species.  At best, the stack will not dry.  There are two basic techniques for stacking wood to air dry.  The European system is preferred by craftsmen and custom woodworkers.  The boards are stacked in sequence, with 1” thick spacers (called “stickers”) between the boards to allow air to pass through.  The European drying method makes it possible to bookmatch pieces and keep wood with similar color and grain patterns together.  The slab goes on the top of the stack to shed water.  It helps to put straps around the stack keep it from warping, and to make it easy to move the entire log with a fork lift or front end loader.  The disadvantage is that it takes more space in the mill yard and in the kiln, and it takes longer to stack.

The more conventional way to stack wood for air drying is to build the stack in layers, with a 1/2” to 1” gap between the boards, and 1” thick stickers between the layers to allow air flow.  This is a more efficient use of space, but the boards tend to get out of sequence.  All the boards of a given row need to be the same thickness to keep the rows even.

Either method requires a foundation.   The stack needs to be at least 6” above the ground.  I generally cut 6” square cants out of the worst logs for this purpose, since they will be in ground contact, and probably not usable for lumber by the time you are through with them.  For the conventional (square) stacking, 4’ lengths work well, but it could vary, depending on your needs.  If you will be stacking the lumber directly from the mill, cut the foundation first, so you don’t have to handle the lumber twice.  The foundation cants should be about 20” apart for 1” thick lumber—any further apart, and  the boards will sag a bit.  I put 1” thick stickers on top of the cants just for a little more air flow under the stack.

All boards on a layer need to be the same thickness so that the next layer will lie flat.  Try to have a 1/2” to 1” space between them for air flow all around the boards.  I generally set the worst boards (usually from the center of the log) aside until I have a half-dozen, then put them back on the mill and saw the stack to pieces 1” thick.  It makes a lot of stickers in a hurry!  Part of the art of air drying lumber is keeping stickers perfectly lined up so the weight of the stack transfers straight down to the cants.  Build the stacks as high as you can reach, or whatever your loader can lift safely.  Top the stack off with one last row of stickers, then roofing tin, or a layer of scrap boards to shed rain and snow.  I don’t use tarps, because they can trap moisture.

Then comes the really hard part… wait. The rule of thumb is 1 year per inch of thickness, but that depends on the species, your climate, and whether you plan to kiln dry it.  You can kiln dry wood at any point, but the drier the wood, the less time it will spend in the kiln, and the less it will cost you.  20% moisture content is a good target for putting wood into a kiln.  A good moisture meter comes in handy.  

hamish24
hamish24's picture

Dave,

 

Another point to mention.  The lumber is degraded by exposure to the sun, the initial effect is the greying of the boards, which is not a big issue if they are going to be secondarily processed when dry, but are a killer if trying to market them, most sellers dnt want greyed boards.  Simple solution for air drying outside, make your roof surface larger, and create a breathable sunshade for the perimeter, geo-textile (aka landscape fabric) is economical and effecient.

 

Jeremy

eddiemac
eddiemac's picture

When I stacked my lumber outdoors, I found it most practical to have 42" wide stacks covered by 1/2" CDX plywood (with weights on top).. While roofing tin makes a good cover, the old holes in any tin I have reclaimed eventually introduce degradation to the sometimes valuable lumber they protect. One can always fill the holes with silicone caulk, but the thought of steel panels flying through the air toward my mother-in-law's house during our recurring heavy winds makes me think plywood is a best (though no optimal) solution. By the way, yours is a very clear explanation of just how it should be done (great pictures). I guess I'll have to go to 20" spacing (I've always done 24").  

Post Oakie
Post Oakie's picture

Sounds like you and I could both use some drying sheds!

eddiemac
eddiemac's picture

Problem solved  -   until I run out of space.

swampbuggy
swampbuggy's picture

I like to make sure I have stickers at the ends of each row. Otherwise the ends may warp. Looks like all the pictures addressed that. Thanks for the pictures! Dan

Post Oakie
Post Oakie's picture

Nice stack of lumber!  Looks like its got good air circulation through it.  What will you do when you've filled up the pole barn?

eddiemac
eddiemac's picture

I'm trying to whittle down the stacks by using the lumber myself for my various projects and restraining myself somewhat from acquiring more logs. That my be hard because so many trees died last summer due to the drought.  I'm not in business except that I custom saw when anyone asks.  Recently retired and now signed up for Social Security, I suppose I could be called a hobby sawyer and probably part of Romney's 47%.  I've built a woodworking shop and plan to entertain myself creating useful and beautiful objects.  Here is a photo in my shop with my recently completed cabinets made with unstained, varnished post oak, 56 drawers and two doors waiting installation.

004-1 004-1-1.jpg photo
Dewchie
Dewchie's picture

Beautifull looking shop. Always wanted one just like it and soon with my ML24 I hope to achieve that. Thanks for the great pics. 

eddiemac
eddiemac's picture

Thanks Dewchie and Post Oakie  -  the shop is a dream that's finally come true.  P.O. : will contact.

Post Oakie
Post Oakie's picture

Nice shop.  Building with lumber you cut yourself is great.  I see you're from around Stockton, MO.  I live 20 miles south of Joplin, which practically makes us neighbors!  Drop me a line if you're going to be down this way, and we'll talk sawmills.   I'll PM you my contact info.

Bill
Bill's picture

Eddie that's a great looking shop TY for posting.

  Bill

Post Oakie
Post Oakie's picture

Eddie, no sawdust anywhere!  You must have a heckuva dust collector (or broom, in my case), or cleaned up the shop just for the photos.  Are you finishing the wood in a kiln, or putting it up air-dry?

eddiemac
eddiemac's picture

It does get dusty as some of the machines are not yet hooked up to the dust collection system, and some may never be.  I usually sweep the floor at the end of a project and that's probably when I took that picture.  You've hit me, though, at a weak spot  -  lumber drying.  A future project needs to be a solar kiln, but for now everything is air-dryed.  The cabinet wood was probably air-dried for a couple of years (at least) and then kept in the shop to further dry (the shop is wood heated).  I know the problems associated with insufficiently dried lumber and have experienced them in my own house which is also wood-heated and gets very dry in the winter.  Oh well, big deal  -  if you saw my house (built on wishful thinking and adapted to ever since)  . . .

I do have a good dust collection system with a 3HP cyclone collector which will eventually be used by all the stationary machines.

 

 creations009800x600_zpscd557968.jpg photo 

Back to drying, here are my outdoor stacks a couple of years ago when everything had to survive in the great outdoors.

 

 016800x600.jpg photo

 

Dewchie
Dewchie's picture

I remember when I took cabinet making a few years ago they taught us to dry 1year for every inch and paint the ends this was in a shop. Also the moisture content had to be around 5-7 % for furniture. However we all know that wood can take on the moisture content of your house.

Again what a nice shop looks somewhat like the one I work in.

Bill
Bill's picture

 Eddie I really really like that shop . I was a carpenter for 40 yrs. but wouldn't consider myself any kind of a cabinet maker , installed a few hundred kitchens and made a few custom cabinets for others and a few things for myself and family members. Now the shop is for hobby stuff & cedar out side benches and tables when I get bored in the winter and can saw or work in the bush. When you have a shop set up like yours it's a pleasure to get out in it and play all day. As far as drying lumber goes there are many variables, time of yr. the tree was cut, dead or alive, proximity to water table, type of wood . I've air dried 4 1/4 birch in less than a yr. down to 9% and after 1 to 2 wks. in the shop with wood heat it went down to 6% flipping the boards every day.  I've air dried quarter sawn 1" fir for 5 yrs. brought it in the shop for 2 or 3 wks. built some thing and it still shrunk ( 12" panel 1/4" ). An other words time and experience is the best teacher and a solar kiln a great asset. I've been going to build one for the last few yrs. but other priorities just kept getting in the way maybe this is the yr. I enjoy this form and learned a lot here nice to see some action from members contributing .

  Bill 

eddiemac
eddiemac's picture

Thanks for the comments.  It's all a big learning process for me, something that I like doing and hope to someday be good at.  I've found that good tools definitely make a difference, after doing things the hard way for many years.  A kiln is one of those tools I need in order to really do things right.  But I'll suffer 'till then  -  it's all grist for the mill.  I've never been a carpenter, but I've built a house and a barn. Never an architect, but I've designed things.  Not a mechanic, but I've overhauled engines.  I just like doing things for myself and have learned a lot  -  frequently by the longest routes.  If my shop cabinets don't hold up, no big deal.  If won't be the first time I've had to start all over.   And yeah, it's nice to see some movement on this forum.  There were more contributers back in 2004 when I bought my mill.  Guess they got tired of covering the same territory.     

Greenthumb
Greenthumb's picture

Eddiemac Greenthumb here you mentioned  a kiln I was looking at a good site on google the site was called Virgina Tech Solar kilns take a look and tell me what you think . Thanks 

eddiemac
eddiemac's picture

Yeah, that's the one I've been looking at too.  Been thinking about building it, seems just right for me.  Will post pics if I do.

Greenthumb
Greenthumb's picture

Thanks looks easy to build and not hard on the wallet  coating the ends of the cuts looks to save you allot of lumber . Hey would it make sence to coat the end of the log before you mill it then sticker it . What's your thoughts . Thanks 

eddiemac
eddiemac's picture

Yeah, I believe that is the best way.  A lot of checking takes place soon after the log is cut.  That said, I must admit I've never coated the ends of anything, and yes, there is a lot of waste at the ends of my lumber.  I cut my logs long and cross my fingers.  It makes sense to coat the ends of the more valuable logs though.

Seasoned Carpentry
Seasoned Carpentry's picture

I dry all my lumber outside under sheds built with 6 mil white tarps I purchase on Ebay. I made my tractor shed out of this same tarp material, bought a huge tarp, 30'x40' for the roof and smaller ones for the sides. The frame is built with poles I squared, three sided, or two sided on the mill. The roof is made with round poles. All is screwed together using the hardened lag screws on the market now that cut their own threads. I predrill in hardwood, and drive using my makita 18 volt drivers, not a drill. Makes a fast, inexpensive shed for tractors and lumber. The tarp material goes through two summers, then I add a new tarp. Two layers on it now.

I air dry all my lumber and use it to make furniture as well as in my remodeling business. Wood moves, swells and shrinks according to humidity, doesn't matter whether kiln dried or air dried. Kiln drying is faster, but not better. As soon as lumber is out of the kiln, it absorbs moisture until it is at equilibrium with the humidity around it. So essentially it reaches the same moisture content rather quickly as air dried lumber does in the same humidity.

Building furniture you have to plan for wood movement. I rarely use plywood in my furniture, building out of glued up solid wood. The bigger the glue up the more it moves. You have to make sure you've allowed for that movement. The plywood and particle board furniture on the market doesn't move as much, till that particle board gets wet, then it swells to a useless mess. Plywood with interior glue becomes useless when wet also.

I'm not a real neat stacker, nor do I use stickers at the recommended spacing. I don't paint the ends. My lumber comes out pretty straight, and if it doesn't I use it where straightness isn't essential or use it for short pieces. I saw all my boards at 1 3/8" thickness so I can plane out any cupping, which virtually all wood does, and still get a full 1" out of the lumber. Sometimes I can get 1 1/8" out of the flatter pieces. I don't sell much lumber, I use most of mine creating furniture or sheds. My advice is neatness is nice, but for me I don't have the time to be that neat, and sometimes (most of the time) I push sticker spacing to the max. My lumber still creates beautiful furniture. and nice straight boards.

DaveM
DaveM's picture

I tried using tarps for a shelter before. With the snow freeze & thaw cycle in western NY, the ice buildup made short work of the tarps. Did you experience the same thing, & if so, how did you rectify it ?

Post Oakie
Post Oakie's picture

I use a product called Anchor Seal from U.C. Coatings (uccoatings.com).  They have it in 5 gal buckets.  Definitely best to put on the ends of logs right after cutting them.  As soon as cracks start to form, it isn't nearly as effective.  Seasoned Carpentry, it sounds like you've found what works for you.  You're exactly right about building furniture to move, especially tables and other pieces that use wide boards.  When you get around to it, how about posting a few photos of your work?

Seasoned Carpentry
Seasoned Carpentry's picture

I wish I could post images directly here rather than hosting them on Photobucket. It's twice the work to post them there, and then link them here. I will try to get around to it, but free time can be difficult to find.

eddiemac
eddiemac's picture

One thing a kiln does (I hope) is kill insect pests and fungi.  I've had problems with powder post beetles in several species and worms in the sapwood of red cedar.  I imagine prompt sawing of new logs would lessen those problems, but I often cut standing (or even fallen) dead trees and sometimes don't get around to sawing as soon as I should. 

Post Oakie
Post Oakie's picture

It takes an hour at 135OF to kill off the bugs & fungi.  The kiln would need to hold that for 4 hours for the heat to reach the core of 2" thick boards and hold it for the required time.  Drying wood alone won't kill the fungus or the bugs.  Worst case scenario would be selling a piece of furniture to someone and causing a powderpost beetle infestation.

S.C.,  I spent considerable time trying to upload photos directly to this site... no luck.  Photobucket isn't a bad way to go, though.  I've found it handy to have a collection of photos available for public viewing.  Very easy to upload, once you've set up your gallery-- just drag and drop, and easy to transfer images to the forum.  Here's a link to a discussion about photos. Posting Photos

Seasoned Carpentry
Seasoned Carpentry's picture

Thanks PO. I do have an account on Photobucket and quite a few photos and albums there. Yet it is one more step in the process. I like the forums that you can simply paste photos into. I sell my stuff on Ebay and when they went to direct hosting of photos, I used Photobucket a lot less. I used to embed them in my marketing, now I use the direct hosting. The same happened with Craig's List, you can now post a bunch of photos directly and no longer need to host them on Photobucket.

My hobby is photography and I've been doing it all my life, including back in the days of film. Digital is so much nicer. Since my main photo posting no longer needs Photobucket, I don't use it all that much anymore. Sometimes I even forget my password there!

Post Oakie
Post Oakie's picture

How about a link to your Photobucket so we can see some of your work?  I'm always interested in what others are building.  Yeh, I remember mixing Dektol developer and processing film.  I still think it would be fun to get a good medium format camera.  First time I printed digital photos, I had this strange impulse to turn off all the lights before putting the paper in the printer.  Go figure.  Lots of changes, whish more of them were for the better. The times, they are a' changin'!

Elmer
Elmer's picture

I'm wondering how long CW [cottonwood] would take to dry in western Kansas? Like 2x6, 2x4, 1x8,
Elmer

r.garrison1
r.garrison1's picture

I am a very strong proponent of sealing the end grain, and doing what you can to stabilize the wood for furniture.

A few years (OK, decades) ago I worked in a furniture shop that made a lot of Oak furniture. This was in Oregon, about 250' above sea level.
One year, we sent a couple truckloads of furniture to a Denver show, trying to expand our market. We put a lot of effort into the furniture, so it would really show off what we could do.
A couple days into the show, the furniture started warping and spliting. When you have this happen to a dining room table, it really makes you sick.
The difference was the humidity difference, the altitude, and the temperature of the spring show. The wood really wasn't ready for the level of change it experienced, so all that work went for nothing, and we closed our booth three days into the show. We had been to a number of more local shows before, never a problem. We had been making furniture for years, never this as a problem.
After that, nothing left the shop without the wood being sealed.

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