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Air drying ERC

Started by DPatton, July 18, 2019, 07:18:32 PM

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DPatton

I have a customer who wants me to custom saw a wack of ERC logs for him in a few weeks. He has a new, dry, insulated, enclosed metal building he wants to stack and dry the lumber in. I have explained the stacking and sticker process. He wants to buy and use 3/8" x 1 1/2" wood lath as stickers and is capable of keeping fans running continually on the stack. I know ERC is low in moisture content and dries easily but I'm skeptical about the narrow spacing of lath for stickers. I'm sure many of you have much more experience with this than I do so I want to know if the wood lath will work with ERC or are we looking at a recipe for disaster?
TimberKing 1600, 30' gooseneck trailer, Chevy HD2500, Echo Chainsaw, 60" Logrite.

Work isn't so bad when you enjoy what your doing.
D & S Sawmill Services

WDH

You could probably get away with the lath on ERC as it is about as forgiving as it gets, but I still think that it is a poor approach as the drying will be slowed with only 3/8" between the layers.  Imagine how much faster it would dry with 1" thick stickers.
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

GeneWengert-WoodDoc

Use two lath at each spot. Mold is an issue with 3/8". Warp can close the opening 
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

stavebuyer

I had some ERC logs lay around almost 2 years. Weeds growing up through them. Was needing fence posts when I finally got around to sawing but still got several packs of 1" that I intended to put on sticks. The packs sat in closed gravel floored pole barn another year. Boards look like the day they were sawn. Cedar is very forgiving lol. I have often sawn 5/8 for rustic board and batten and used the 2" x5/8" batten for stickers. No issues. 

GeneWengert-WoodDoc

This story from Stavebuyer reminds me of ERC being sawn as heavy 6/4 and dried.  Then both faces planed, then ripped into several different widths (2", 4", and 6", as I recall), and then t&g along the length edges, making two tongues on one edge and two mating grooves on the other edge.  Then the pieces were resawn with a band into two 9/16" thickness.  The end result was paneling that was smooth on one side and rough on the other, plus the square footage doubled.  The company assembled the various sized pieces into 32 Sq Ft bundles..
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

JB Griffin

A neighbor of mine used to build cedar chests and he to cut down the trees , take them to the mill, strip stack the 1" lumber for 7 or 14 days I forget which,  then build the chests with hardly any failures of any kind.
2000 LT40hyd remote 33hp Kubota with 6gpm hyd unit, 150 Prentice, WM bms250, Suffolk dual tooth setter

Over 3.5million bdft sawn with a Baker Dominator.

ellmoe

I've t & g 'd many cedar orders out of fresh cut lumber without any problems . When I purchased this mill there were two bundles of dead packed cedar that had been sitting in the yard , in the weather , for over a year waiting for a logger to pick up . After another year of moving the bundles ( always in the way , somehow! ) , and after harassing the logger to come get them , he finally asked if I wanted to buy them . Much to my surprise , when I opened the bundles they were like new , no rot , no insects . Cypress bundles with the same history had rotted . As mentioned earlier , very forgiving !
If he is going to use thin sticks , tell him to make narrow bundles to ad in drying.
Thirty plus years in the sawmill/millwork business. A sore back and arthritic fingers to prove it!

YellowHammer

I'd either double up the stickers or make narrow packs.  I would not use fans.

Depending on the ERC, fans could do some damage, so I would not use them this time of year.  The ERC here will sometimes surface check in the white wood if dried too fast in the initial stages of drying, especially if the white wood is intermixed or streaked with the red wood. I've damaged it more than once and although ERC has a very high published drying rate, I would sticker it and just let it sit for several weeks before I pushed it.  I've never had any problem with the red sections of wood checking.


This is especially true if sawing ERC thicker, like 8/4 or so.  

Other than that, it is very forgiving.     
YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

GeneWengert-WoodDoc

ERC has a nice aroma.  But remember, the more of this aroma you smell when you are drying the wood, the less aroma that will remain.  The more heat, the more aroma that is evaporated.  So, often the suggestion is to dry the wood at 80 F in a room that is fairly tight so you can control the humidity.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Florida boy

I have a person wanting erc cookies for thanks giving. I k no ow it's well behaved in a board not sure bout the round. Anyone have experience with erc cookies?

doc henderson

any sapwood will be more likely to split, and punky wood will fall apart.  one option used is to mill just days ahead of the holiday.  or space them in a box for slow drying.  or stack back in the same order, but flip them over a time or two a day to release surface moisture that may mold.  hard woods can be soaked overnight in denatured alcohol then dried, but have not tried this with ERC.  you can also mill on a tangent such as 45° and have better success.  there are a few threads on jigs to hold a log upright in your mill.  a rounder tree with less lobulations and bark inclusions prob. is more stable.  here are some pics of cookies i thought looked like Christmas trees or an angel.  must of been Christmas time.  been in the shop for a few years.



 



 

here is a cedar cookie with a walnut for comparison that was soaked in DNA then dried a few weeks in a box, then finished with danish oil.  the sap wood is less dense and dries faster and shrinks more, therefore tends to split.  the cedar was just left in a stack in the shop.



 

i have sawn cookies from a blow down tree and they all split in half as soon as they were cut.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

Don P

Quote from: doc henderson on September 11, 2019, 02:40:01 PM
any sapwood will be more likely to split.   the sap wood is less dense and dries faster and shrinks more, therefore tends to split.  
I've seen several comments along these lines recently. I can understand part of those comments but not sure about all of that. Can you point me to where we are getting this information from?

doc henderson

hey Don.  the sapwood is also the outer most ring so under the most stress.  i have observed lots of cookies and it is the sapwood that routinely splits, often not splitting the heartwood.  after drying, and i rip or separate sap wood, it feels light and has less strength than the heart wood.  it should also have a higher MC it seems, and therefor poss. shrink more.  these have been my observations, not based on studies.  My book smarts are in other areas.   :) :) :) :P
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

Don P

I'm hoping others will chime in with more book smarts.
Here's what I think I know, mostly from the Forest Products Labs "Wood Handbook". The mechanical properties of heartwood and sapwood are the same, those tables do not have different strength values listed for heartwood and sapwood. Density is not subdivided by heartwood and sapwood, nor is shrinkage in their respective tables. Moisture content is.

What is heartwood?, sapwood that the tree pooped into. With enough extractives the cells can be bulked in some species and it might have somewhat higher density but those extractives are not wood, it isn't contributing to strength in the sense of the way I think of density. They may change drying rate. Sapwood has higher moisture content, but that is free water which doesn't affect shrinkage, heartwood is also above fiber saturation point so has not begun shrinking in the green state either. Shrinkage only begins as the moisture bound within the fibers of the cell walls begins to leave. Think about the comment you just made, the sapwood feels light but also has a higher moisture content, and its weaker. I think your eyes are leading you to make a conclusion that wouldn't be the same if really studied.

My aim here isn't to pick on anyone but to think critically rather than repeating things within our group that might be wives tales. I also welcome being wrong if I can learn something new.

doc henderson

i welcome your input as well Don.  i try to be accurate, but these are comments made from my observations, and we all know that science is better than assumption.  Also if you are ever wrong, i will be sure to let you know!!! :D :D :D :D.  best regards all. good luck with the cookies.    @Don P   @GeneWengert-WoodDoc 
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

YellowHammer

With ERC specifically, because it's a special case where white wood and red wood is intermixed within the log, the white wood, whether it's on the edges of the boards, but especially if it's marbled and intermixed with the red wood on the more interior portions of the board, and especially if sawn more 2 or more inches thick, will surface check much more readily and commonly in the board.  So in that case, with an intermixed board, the red portion will be fine, the white portion, especially if marbled within the red sections, will sometimes check.  Generally not too deeply, but enough for use to notice it that it won't plane out.  

I don't know the reason, and I don't know of any other species we process that has the marbled structure, but it certainly happens.

I can conjecture that the physical properties of the white wood and redwood are different, or that the moisture content of the white wood is higher than the red wood and aggressive drying techniques will cause the white wood to exceed its maximum drying rate while the red sections do not.  

It may also be that there are different properties of the heartwood and sapwood. From a technical standpoint, I don't know why observation and published information don't match but I have seen it may times and there is generally a simple answer.  

There have been some interesting points raised.
YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

Don P

In any other wood I would call that marbelling traumatic heartwood but I'm not sure that is the right term for ERC. It looks more like stranded sapwood, effectively heartwood in that it is dead but it didn't get backfilled with extractives, just guessing.

I do agree with that observation and my guess is that heartwood, full of extractives and blocked conduction pathways is less permeable than sapwood. The drying rate is different.

I'm not saying published and observation are necessarily different, there are many variables we are kind of wandering across. For instance Doc brought up another, there is more growth stress in the outer shell. The tangent chord is also longest out there, getting back to mechanical differences rather than heartwood/sapwood. Part of what I really enjoy about wood is the more I know, the less I know :D

Don P


WDH

One reason the sapwood cracks more than the heartwood is that the sapwood is on the outside and that is where the stress from the differential shrinkage, tangential versus radial, first shows up, tangent chord and all. 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

doc henderson

I agree.  in some of my samples the crack seems to stop at about or just into the heart in ERC, oak rounds (cookies) will split through the whole thing to the other side.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

Don P

Take your shop bandsaw and cut the sapwood off a cookie. I've never tried it and there will be a shorter tangent chord but I'm guessing it will still crack. That is the radial/tangential shrinkage problem rather than a heartwood/sapwood problem.

I learned something today reading another piece on ERC, the French called it Baton Rouge, red stick.

Which brings to mind the name of another city I learned recently, Chicago came from an indian name meaning place of the wild onions.

doc henderson

yes and they even named a city after it!  :D  some will cut a center out of a cookie and it will be less likely to split.  different woods dry different so the wood structure has to have something to do with it.  the diameter and thickness has something to do with it.  
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

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