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Drying 3" Oak slabs

Started by Hooterspfld, December 28, 2018, 10:47:32 PM

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Hooterspfld

Looking for some advice on drying some oak slabs I recently cut with my Alaskan chainsaw mill. I ended up with 8 3" slabs 28" wide and 10 feet long. After the tree was felled, both ends were coated with Anchor Seal prior to slabbing. Right now they are sitting on the trailer as I have not decided what route to take prior to kiln drying. I have 3 options really and am curious if anyone has any advice as to what route to go. 

Option 1: Move slabs into my basement bedroom and stack and sticker. (It's my thought that the more regular temperature and humidity might help reduce checking. On the other hand perhaps the warm 70 degree temperature and low interior humidity might be to aggressive...)

Option 2: Move slabs into my garage and stack and sticker. (Temp and humidity will swing greatly in this case... Here in Missouri it was raining and 65 yesterday and clear and 25 today.)

Option 3: Stack and sticker the logs outside with a cover to keep the rain off. This to me seems like the most detrimental of the 3 options due to wild swings in temp and humidity. 

Also, I have the materials on hand to build a dehumidifier kiln with realitively little cash out of my pocket. However realistically that won't be compleated until this summer. Would 6 months of air drying in one of the methods above be suficient to prepare these oak slabs prior to sticking them in a kiln environment? This so far is just a hobby endevor, with the goal of making some natural/industrial type furniture to keep/sell/gift. My budget has been practically spent on getting 2 nice chainsaws and a trailer to haul wood. So unless I can pick up some odd jobs cutting trees, I'm hesitant to spend much more without some results. Any advice would be welcome. Thanks! 

Ianab

I'd suggest air drying outside as the safest. The temp and humidity changes aren't your problem, and in fact the colder and humid periods will simply slow the drying, which is good with thick hardwood. A "solar kiln" works by going through a heat and cool cycle every day, and that lets the wood recondition and even out it's moisture again after every daily burst of drying. 

Inside would be the worst as the wood will try and dry out too fast, the outside skin dries and shrinks before the water can move from the core of the wood, then bad things happen. Also, the moisture given off by green oak is pretty corrosive, you likey don't want that inside.

Once the wood is "air dry" THEN it would be safe to restack inside to lose the last few % of moisture. It's hard to mess up once you get the wood down to ~15% or so.

You can kiln dry oak from green, but thick stuff like that has to be done on a VERY cautious schedule, and that means tying up the kiln for an impractically long time (expensive). So air drying first is more practical. 
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Hooterspfld

Thanks Ianab! 

That makes a lot of sense. Do you think there would be any problem with drying in the garage? I live in the city and don't have access to alot of the equipment and space that many people on this site enjoy. Would be less work to stack and sticker in the garage, and I would be sure to have a firm flat surface rather than stacking outside. It's not a heated garage and would be similar to the outside temperature although a bit milder. Also does 6 months or air drying sound practicle to prepare the slabs for a kiln?

Hooterspfld

Well for better or worse I stickered and stacked it in the garage. Would have torn up the yard trying to get it in the backyard, and I'm not sure my neighbors would appreciate it as much as I if I left it in the driveway. Not sure what these actually weighed, but I'd guess around 300 lbs a piece. Lets just say that after moving 8 of them by myself, I'm ready to let them set for quite a while!

 

nybhh

Looks good!  I dealt with a few few 10' 2.5" ash slabs today and had to call the wife for some extra muscle.  Solo 10', 3" oak is impressive!

If your garage is unheated, I actually think it might be better for the early stages than outside as it won't get any wind.  I think really wet wood dries more from air movement than temperature so in the early "dangerous" stage, I personally think this is a great option.

One thing I might add though would be 3-4 heavy-duty ratchet straps cinched around the stack.  Re-tighten them every few weeks as the wood dries.  A little cheap insurance to hopefuly help keep everything nice a straight.
Woodmizer LT15, Kubota L3800, Stihl MS261 & 40 acres of ticks trees.

Hooterspfld

Thanks nybhh,

Yeah I thought about the ratchet straps after I had already moved about half the stack. At that point I was not about to start over. I think today I'll see if I can manage to get some straps on it today now that I'm rested up. If not then I'll probably put on another layer of stickers, some 2x6's and just add a bunch of weight. Got plenty of heavy things in the garage that can go on top.

GeneWengert-WoodDoc

Thick oak requires slowdrying.  Normal air drying,especially in MO, would be too fast some days.   The conditions outside are ok for 4/4 and even 6/4, but you need to dry half as fast.  So, outside with Shade Sri on the sides and a roof for rainprotection would be good.

The garage would be the best of the three if you also have a small fan to stir the air.  Otherwise you will get mold growth as some spots will be too humid.  Eunwith the garage door open a lot during the day.  However, some days will have under 40% RH, which is too dry for the first three months, so close the door then also.

The wood should be ready for a kiln in about nine months.

Ratchet straps for thick oak wood will will not help with warp.  In fact, they do not even help with cupping or side bend for thinner oak.  The forces with oak are too large.  A top weight of over 100 pounds per square foot will help somewhat for thinner oak. For 12/4, three times more.

Things that do help...planing the surfaces will increase their strength and resist checking.  End coating.  Avoiding drying too fast above 35% MC.  Perfect stacking. Avoiding rain on the lumber. Avoiding slow drying.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Ljohnsaw

Quote from: GeneWengert-WoodDoc on December 30, 2018, 01:15:11 PMThings that do help...planing the surfaces will increase their strength and resist checking. End coating. Avoiding drying too fast above 35% MC. Perfect stacking. Avoiding rain on the lumber. Avoiding slow drying.

Doc,
I really appreciate the vast knowledge you so freely share.  I sometimes get overwhelmed with the amount!  I have to read carefully because you switch between MC and RH and I sometimes miss that.  I think at one time you gave a comparison of what a RH level would allow wood to get to what MC level which escapes me at the moment.  So I will paraphrase what I *think* you are saying above:

When the wood is very wet (fresh cut?), don't try to dry fast.  Meaning avoid low RH environment and/or a lot of air movement.  End coating and perfect stacking are a must as well as avoiding re-wetting the wood.  You mention to avoid "slow drying" but what are the parameters of that?  Just have *some* air movement but not a *lot*?  Without measuring tools, could that be quantified as a cool breeze that barely musses up my hair (if I had any!)?  Or something a bit stronger?  The first tip I don't understand - planing the surface?  Are you saying you want a dead smooth surface as opposed to a rough-sawn one?  So that there is less surface area (at a nearly microscopic level) exposed?
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

GeneWengert-WoodDoc

Planing creates a stronger surface, as a saw leaves a surface full of tears that develop into checks perhaps 12 times easier.

The RH we want is around 92% RH for green oak of 12/4.  Low air flow also helps...no more than 100 fpm for thick oak.  Temperatures around 80F are great.  We want to dry around 1/2% MC loss per day...that is slow.

Ok?

Thanks for your comments
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Hooterspfld

Thanks for the info Doc!

I'm going to put as much weight as I can on them. I've got 27 cases of 18" tile that weigh 61lbs apiece. Even then, I'm only at 1700lbs, well shy of the 6000lbs you suggest. I can probably get it up too 2000lbs with what I have laying around. With these slabs being 2'x10' if i were just using tile, that's 100 cases of tile... I'm going to have to do some thinking on this one!

doc henderson

had a few other ideas.  If you cut a little thicker than you need, you can put back on the mill in a year or so when you are ready to use.  Take off a 1/4 inch or so to flatten if you have some warp or cupping.  I go to lowes or HD, and get their shipping boards made with a groove for strapping to put on the bottom of the stack.  They are 44 to 48 inches long and inch and a half tall.  Many are pressure treated.  I can feed steel strapping under this and really tension this as well as move the whole stack with forks (that you don't have).  I also with watch for good pallets that are long and narrow and then can move also with a pallet jack ( cheap at HF).  Or use a hand truck 2 wheel cart and pry/lift and end and place a roller cart under an end, then can lift the other with the cart and steer if you need to move a little.  I have discussed this with them and have permission.  I want to try the nylon strap so it can be re-tensioned.  I usually strap up a single cant stacked and stickered but this does allow the whole stack to twist a little.  May hold it some in the beginning.
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

doc henderson

looks like you have a dolly in the pic.  you could lever or pry up an end and change out your bottom stickers or add the straps.  from your measurements you have about 47 cubic feet of oak. Gene could maybe comment on total weight.  I would guess depending on how wet, at least 3,000 pounds. If the final use is rustic, a little movement of the wood may be ok.
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

Hooterspfld

Thanks for the ideas Doc Henderson!

Well I got about as much weight on it as I think I'm going to get (2200lbs+). I cut these on the large side knowing I'm going to have to take them down a bit to flatten and smooth them out. I'll probably stick with this until I can get a better place to store them. I've got a buddy with a horse barn that they don't use, I'm going to inquire with him to see if I can use a couple stalls to dry lumber. If I get the ok, then I think I'll move it there and restack with more weight. I can pick up 55 gallon drums pretty cheap and fill them with water. Figure I could get 10 of them stacked on this tree, that'd get me around 5000lbs, plus it's alot easier to turn on the hose then actually moving 5000lbs!



 

moodnacreek

Back when we had normal summers, oak sawed and put on sticks might face check badly. I once read that this was from damage done by the saw. It was said that green planning could eliminate this problem.

JPMcCullum

I don't have near the level of knowledge as some on this thread, but I've got a pretty good stack of 4"x~30"x12' white oak slabs that are nearing the 4 year mark in their drying. I anchor sealed as well as used metal strapping and tico nails in the end grain to -attempt- to minimize checking. It seems to have done it's job thus far, even in the two pieces containing the heart of the tree. I'll let you know if there is any springing when I remove the straps. 

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