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Drying green pine

5K views 21 replies 13 participants last post by  Tony B 
#1 · (Edited)
I've never dried green wood before. I've never worked green wood before either, except a few scraps here and there. Usually I buy kiln dried wood.

My sister-in-law's family finally broke ground on their house a couple of weeks ago. They are using the pines (probably Eastern White Pine?) they cut down as timbers, so the logs were all milled on site. I inherited a pile of scraps, some quite sizable, all 100% green. They range in thickness from 1" to 4", and in width from 1" to 12".

They're currently stacked out of the rain, in the back of my shop. I've got them separated with sticks to air dry. The shop is not climate controlled. This is North Carolina, so temps range from low 30's in the winter, to high 90's in the summer. Humidity is always generally high.

So, how long before this wood is conceivably usable? I was thinking of making simple 3- or 4-legged stools. Turn some spindles, and put a seat on top. Wedge the ends of the spindles for joinery. Something like this: https://www.rockler.com/turn-shop-stool-turning-assembling-legs-spindles-seat

If I cut the boards into rough pieces for these stools, will they (a) dry more quickly, (b) warp and check less?
 
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#3 ·
I've always heard that pine is "easy to dry," the reason for that (I think) being the moisture content of green heartwood for certain species is relatively low. Of course the counter to that is the MC of the sapwood is relatively high. I always let my stuff dry for a long time, but that's only because it takes me forever to get around to doing anything. I would think if you're using heartwood it would be safe to use fairly soon, but if sapwood it might take a while, and I don't know if you can tell the difference by looking at it. Depending on how many stools you're making you may be able to store some material indoors for faster drying to a lower MC than what you will achieve in a shop. As for cutting boards to rough dimensions first I would guess - yes to drying faster, probably no to more checking, and probably no to more warping if you get them stacked and weighted down pretty good. In my experience the warping gets worse the farther you are from the pith and doesn't necessarily relate to how it stacks and dries, again the converse to that is you always see checking at the pith. Might be worth investing in a moisture meter, cheaper ones run 30-40 bucks and are worth the money for occasional use in my opinion. I'm still new to milling and drying and I've probably spent more time reading about it than actually doing it so take this for what its worth.

(some handy info https://www.researchgate.net/public...ure_Relations_and_Physical_Properties_of_Wood)
 
#4 ·
I have used Darrens plan for several years with pretty good results. From what I understand pine requires a high temp to set the pitch - as I remember it's about 140 degrees or more. That's higher than I can get without using an additional heat source so If I need pine I just go to Lowes.

Wood will air dry to different levels in different locations of the country. For me in North Florida that is around 13% M/C at a rate of 4/4 (1 inch) per year. I found a spot in Arizona where the same dimension will dry to 3% also in 1 year.

I've also found that letting your logs air dry for a while will reduce warping, checking etc after milling. A least a year out of direct sun.

I suggest you search the posts by this member. He's been at it for quite a while but hasn't been here lately.
https://www.woodworkingtalk.com/members/tennessee-tim-17187/

Good info here
http://www.woodweb.com/knowledge_base/Humidity_Temperature_Wood_Moisture.html

When running my kiln, I use this http://www.csgnetwork.com/emctablecalc.html to check on the estimated M/C of the wood inside.
When it gets to a 6% level I usually let it run another 2 weeks for it to stabilize then turn off the D/H for a few days for a slow cool down.
It only takes 90 degrees and 30% R/H inside the kiln to dry wood to 6% - eventually. I use an indoor outdoor thermometer with the outdoor sensor inside the kiln.
 
#6 ·
I suggest you search the posts by this member. He's been at it for quite a while but hasn't been here lately.
https://www.woodworkingtalk.com/members/tennessee-tim-17187/
.
Tim is unfortunately no longer at the site. I dunno how much I can say before the hammer swings back and nails me instead, but there was an issue with a moderator a while back abusing power, Tim spoke out and the hand of fairness punished them both.

You might still try messaging him, Tim is a great guy and THE guy to go to for any questions involving green wood, but unfortunately I wouldn't hold your breath waiting
 
#10 ·
I think during colonial times, trees were cut in the winter when there was snow and transported on sleighs with oxen or horses to the site. where there was no snow they used a large 2 wheel cart with one end of the log slung up and dragged the log.
 
#11 ·
Dylan, I strongly recommend treating the wood for insects. Pine is particularly susceptible to borers.


Insecticides will not work. Use a borate termite based product. I use Bora Care.


General rule of thumb for air drying is 1 year / inch of thickness.


You can rough turn leg stock from green wood. Greatly speeds up drying time.
 
#17 · (Edited)
A tree in log form is basically two parts, The inner diameter is heartwood, and the outer diameter is sapwood. The sapwood was generally split or sawn away as waste. Sapwood is the living part of a tree that carries nutrients to feed the tree. The heartwood id the dead part of the tree that is ridged and usually slightly darker in color. Sapwood is just that...sappy. Sapwood also attracts bugs and woodworms because it still has nutrients for them to feed on. Many times you will find sap laden boards even if it is kiln dried, due to mass production at the saw mill.
 
#19 ·
Drying Pine

Greetings, I dried about 3000Bf of pine outside using 1" stickers every 4 ft and stacked 5 ft high. I covered the piles with nylon privacy fence found on Amazon to keep the direct sunlight off and let moisture escape. After 1 year I started using it and it did not Bow or warp and was great wood the work with. Could have used it earlier my guess. Pine is an easy wood to air dry.

I did spray pesticide on and around to keep the bugs off, I used Malathion I believe.

Happy woodworking
DrGeorge
 
#20 ·
Building furniture and barns out of green wood uses a slightly different technique than kiln dried wood. With green wood, they take advantage of the wood shrinking and holding tighter around mortise and tenons and notched and pegged stuff.
With air drying, the general 1" per year is used as a rough guide. From what I remember, which is not much, air drying in most of the US will only get down to about 13% MC.
There are 2 types of water/moisture in the logs. One is free water and the other is bound water. Picture the end of a board as a bunch of soda straws. The free water is the water that runs through the straw and readily dries off - comparatively speaking. The bound water is in the actual cells that make up the straw and this is the stuff that wont normally dry without a kiln. You can disregard some of this if you live in the desert.
Anyway, that is how I remember it so feel free to shoot me down.
 
#21 · (Edited)
Thanks y’all for the advice on this.

Having never worked green wood, I whipped up a little rustic step stool last weekend from some of the smaller scraps. Nothing fancy. I used a homemade draw knife, a makeshift shave horse and turned the dowels on the ends. I shaped the underside of the top with hand planes and a rasp. It was fun.



I’m going to go green for the bar stools, as suggested, but they’ll be more finished and less rustic. The legs will be fully turned, rather than half-turned and half roughly hand shaped. And the tenons will be flush with the top.

Edit: Sorry the pic is upside-down. I have no idea why that happened, or how to fix it.
 

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