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View Full Version : Air Drying Stacks (Revised)



Bob Smalser
05-04-2004, 10:46 PM
A couple Aussie sawyers suggested that if this wet wood was as squirrelly as some of theirs, that I didn’t use enough bearers. They were correct…been milling easy, stable softwoods so long, I don’t know what I was thinking of…so I fixed both the stack and the post:

RE: “Big Madrone” Posted Below and at:

http://media5.hypernet.com/ubb/ultimatebb.php?ubb=get_topic;f=4;t=002338

From 10 tons of 8’ logs…

http://pic3.picturetrail.com/VOL12/1104763/4110272/50978740.jpg

…the 240-year-old Pacific Madrone was milled into flooring, stair tread/threshold and turning stock, along with the flitches taken from the slabs…

http://pic3.picturetrail.com/VOL12/1104763/4110272/51164646.jpg

Madrone is a relatively unstable wood, benefits from slow drying, and a wide stack is made using 4/4 dry cedar stickers:

http://pic3.picturetrail.com/VOL12/1104763/4110272/52876879.jpg

On a small hilltop with good airflow, cedar slabs were laid on the ground and shimmed flat…not necessarily (or even desirably) level, but flat. For 8’ stock, five 4X6 DF bearers were laid square, and the flooring stock stacked in layers or decks tightly with the edges touching, 90 degrees to the bearers followed by the heavier 5+/4 stair tread stock. Each layer of stickers is positioned directly atop the bearers, and the stack is laid to slope outward slightly as it gains height to provide shade. A few layers of beveled cedar siding top it to provide shade. Light builder’s felt or tarpaper will be applied just to the top surface later. Tarpaper, Tyvek, and some commercial products made for the purpose don’t condense moisture beneath as severely as plastic.

The wetter and more unstable the wood, the closer the bearers must be until the wood dries to equilibrium. On stable woods, I can get use 36” between bearers for 4/4 stock, but as this Madrone is both wet and subject to shrinkage and warp, I use 24” here.

To slow down drying of the end grain to minimize checking, the log ends were painted with Henry’s #107 Roofing Compound…tar in a water emulsion that dries like paint and doesn’t smear during sawing. The preferred product for this is a wax emulsion called Anchor Seal…very effective but also very expensive. This Home Depot tar at 3 bucks a gallon works as well and much better than common paint (by all means use any old paint rather than nothing) …but it adds a step. I’ll have to chop those tarred ends off before running this stock through the planer.

The flooring stock is laid in a 8’ X 10’ stack for the first year. The heavier turning stock is stacked separately. This time next year, the center will be removed from the flooring stack…once the cedar cover is removed the stack doesn’t have to be dismantled, the boards will pull out…to make two, 4’ wide stacks. By then, the 4/4 and 5/4 stock will have reached around 20 per cent…close to equilibrium in this climate…and it will dry to below 10 per cent by September next.

http://pic3.picturetrail.com/VOL12/1104763/4110272/52876888.jpg

One important step many omit. Sure, the bearers were dead flat when I began…I tested them with a straight edge. But then I loaded them with 10,000 pounds or so, and I sight long ways down the boards looking for any bows or sticker pinch…and adjust the bearers with wedges and maul accordingly until the boards are perfect. This stack required minor wedging of three bearers, and I’ll check and adjust again periodically during the summer.

Cedar can be dried in less than half the time of Madrone and other unstable hardwoods and Douglas Fir in a little more time than cedar.

The final tally for the tree was over 900SF of vertical grain flooring and tread stock and another 500BF of turning stock and flitches

Daniel Rabinovitz
05-05-2004, 12:02 PM
Bob
Thank you for the lesson in stacking for drying.
I appreciate it.
Daniel :)

Glenn Hodges
05-05-2004, 12:16 PM
'preciate it

Byron Trantham
05-05-2004, 1:17 PM
Interesting. Thanks for sharing.