Usability Of 12/4 Quarter Sawn White Oak

01/20/2014


From original questioner:

I purchased some 12/4 quarter sawn white oak, for a commissioned 4' x 8' x 2.5" finished size, front entry door. The supplier was very reputable, but had not had much experience kiln drying thicknesses over 2" and we both agreed later that the wood had suffered from some case hardening. The tree had been tracked since it was felled three years prior to entering the kiln. It was dried over a 6-8 week period, MC readings taken, shrink-wrapped and shipped open freight to our shop in NC. The driver did not encounter rain during the transport. The inital MC readings upon receiving the wood were in the average of 8-9% range between two pin type meters. It was allowed to acclimate in it's rough state, in our shop at around 40% humidity for three months. These were 3 thick rough sawn boards of 10-14" width at 9' lengths. They were checked every 10 days with little to no change in MC readings. They were then milled slowly with balanced passes, over a period of a week and a half, to 2.5" finished thickness and widths of 8-12". Tenons were cut on the rails and one test mortise. (The four stiles are 10" wide and will accept full through tenons, top and bottoms are haunched, with two wedges each.) Readings taken from the fresh milled 1.5" thick tenons were over 20% (26% highest) in places, averaging about 16-18% MC. I then put the project on indefinite hold with the customer and built a temporary door for the new dwelling. It sits on the north side of the structure, with a permanent 10' wide porch over the entrance-no direct sun or rain (barring a hurricane) ever touches the door. Installed, the exterior side would have a fairly constant summertime RH around 80-90% with temps in the 90's F and 8-10% RH with 60's F being pulled down by a 21 SEER HE AC on the interior. (How any door survives this at all is the question!- talk about a torture test.)

The wood has been stickered in the same shop environment for 1.5 years now with average MC readings currently of 9-11%, with no discernible changes in size, cuppage or warpage. The lumber initally was surfaced dead flat with an overhead router on a carriage, and remains dead flat and straight. The finish would be a clear marine grade oil/varnish (Waterlox) on both sides with slow set epoxy for joint glue up. Panels are 1.5" thick solid quarter sawn white oak, from separately-sourced 8/4. This door, with full width, rabbeted handmade hammered BB strap hinges will weigh in probably over 600 lbs. The jamb is 8/4 q.s. white oak also.

Do you think the wood is stable enough now to use as intended to construct this 4' wide x 8' tall entry door? Or should I cut my losses now before I invest further into a door with possible joint/finish failure later?

From contributor Da


No guarantees from me, but I think you are fine to go ahead and finally make these doors. If the MC is consistent thru the thickness of the stock, then you will be fine.

I have tried for 40 years to find what MC lumber should be for exterior doors, only to never get a clear answer. I believe and have tested where 6-8&% MC comes up to about 9-12% after a few years, but it is nothing consistent.

However, you mention four stiles, each at 10" wide, for a total of 40" cross grain movement. If they grow, they can move a total of 3/8" gaining 4% MC, and similar amount to shrink. Typically frame and panel work will minimize stile widths to control or minimize the movement - 5" -6" for wide doors.

The movement is going to make a latch hard to work, as well as weatherstripping, retention bolts, etc.

We make 2-1/4" Oak (typically Rift W Oak) doors all the time and use 3 plies to get there. The selection of thicker stock is poor at best, and it is just too hard to dry and too pricey to have some $12.00 a b/f stock move after it has been milled, mortised and assembled into a door.

We have used 12/4 pattern grade H Mahogany for 3" doors, and it works just fine since the kiln people take real good care of that pricey stuff.

From contributor B.


My reaction was like David's. If the core of the board is finally down to the 8% to 10% range I think you are good to go.

I was surprised by David's comment of 3/8" movement over 40" though. I first wondered if he'd forgotten this is quarter sawn material but then thought about it and wondered if the massive thickness might also have some impact. However I would normally expect 3/8" to 1/2" movement in 40" of width in plain sawn vs. quarter sawn white oak.

Thanks,
BH Davis

From contributor Da


Bernie - I missed the mention of Quarter sawn lumber. I think the thickness would not override the basic movement issues. But they are indeed lessened by the use of the more stable cut of Oak.

With paired doors, we just about double the gap at the strike since there is twice as much cross grain wood to expand. We see far more swelling with exterior doors than we ever see shrinking, indicating the doors gain MC over time from when they are built. The Shrinkulator will help with the calculations.

From contributor ri


I'm betting it is still wet in the center. White oak does not like to give up the moisture easily. I'm surprised you haven't seen a lot of small surface checking. When not dried well, white oak likes to check along the medullary rays. Personally, I would have sent it back when you found the moisture issue on the tenons. If my job, I would not build the doors from that stock. But, I would never had tried to make them from 12/4 stock in the first place either. Good luck!

From contributor ji


1 word......laminate.
We glue up white oak to achieve that thickness and have never had any problems.

From contributor B.


We recently got in a load of 10/4 plain sawn white oak that was badly bowed. We sent it back and laminated 2 layers of 5/4.

BH Davis

From contributor Ji


Timber stock has almost no reasonable place within the business of finished casework. The simple fact that you can use it without laminating is a sweet dream waiting on a nightmare.

Besides the exorbitant cost of the material, the shop guys will despise you since they have to lug the logs from one machine to the next (while trying to figure how to turn shop equipment into a logging mill.

After the products are completed, installed or shipped, every big stick that went into the production will be trying to turn back into a tree.

A timber is a timber and great when you need a timber, otherwise you're barking up the wrong tree.

From contributor Wi


I would Go for it. Looks like you have done the due diligence. After all it is Quarter White Oak. As we all know there is no such thing as a straight door stile. They all bow one way or the other and I have never had one change direction. As always pick the best two for the center, use the jamb side to hold the others straight. Every laminated stile I ever made bowed also. I've made a lot of them in every form and fashion. And what I've learned about a straight stile is that it can still bow in either direction

From contributor SL


As is typical of these forums, where woodworker's replies can range from far left to far right, I always find a bit of humor in many of the post's both here and throughout the WoodWEB forums. There seems to frequently be a good deal of stoggy-ness, that is: dogmatic, opinionated "my way is the only way" information. And why should it be any different? We all had teachers and mentors who for the most part usually, taught or showed us only ONE way to accomplish a goal. To offer another solution or method (as an apprentice) was to challenge the savvy and intelligence of our "masters", and at least in my experiences, was often met with rebuke and scoff. As if I knew anything, at age 16.

To reply to the "timber has no reasonable place in finished casework" and to the "laminate" argument's, we have built dozens of solid rail/stile and panel construction doors in the past 20 years, as well as what I call lumber (stave) core/skinned. So I would have to respectfully disagree as to the longevity/suitability of solid wood as a choice. I have always paid close attention to glues, weatherstripping and threshold applications as they are the weak links that make or break the longevity of any window/door in a exterior application. We use some very specialized, adjustable, silicone-based gasketing now that is really impressive. We seal edges/endgrain with multiple coats of vinyl sealer under any topcoat finishes. We cut full or 3/4 tenons with wedges or tension pinned joints. I usually use an (old-timey) math formula to figure and allow for seasonal expansion/contraction. I have inspected doors over 100 years old around the world, build with similar techniques that still look good and perform satisfactorily. I have and still do revisit many of our old doors periodically to inspect and often re finish, touch up or adjust stops, etc. that a customer may have overlooked. It is a good way to maintain contact with customers, acquire new business and references. I have not observed a single joint failure due to our construction methods, in solid wood or laminated construction. However, I have also never (knowingly) tried to use any case hardened material before. Our local sawyer/supplier for many years has retired and we now have no reliable source of 12/4 QS at least in local species. This alone, probably will significantly alter the way I approach door construction/installation for the foreseeable future. I have found decent exotic species like mahogany/sapele in 12/4 from non local suppliers, but seems to be more random in quality and dependability. I guess quality and reliability are going the way of apprenticeships and the dodo bird. As to the question of whether to use this pile of white oak- I am still deciding, but probably will use it on a shop door. I cannot be 100% sure it has reached equilibrium. Thanks for all the responses- I've got to get back to this pile of paper in the office generate some income.

From contributor Ji


You said it yourself and summed it up nicely " I cannot be 100% sure it has reached equilibrium."

Therein lies the problem with thicker materials and therein lies the reason for my "stodginess and dogmatic" opinion. Opinions not based on hearsay or passed along wood-lore, but personal experiences, characterized as "bad and expensive". Also numerous opinions from professionals at Woodwebs' Knowledge Base and other sources:

" I have had over 30 years of hands-on industrial drying experience (20 years with a large furniture manufacturer drying about 1.5 million board-feet per week), and drying thick lumber is still a challenge." - See more at: http://www.woodweb.com/knowledge_base/AirDrying_and_KilnDrying_Thick_Maple.html#st
hash.nZ49t0Nd.dpuf

White Oak is a particular challenge due to the tylosies in the vessels of the wood which "can cause problems during kiln drying, as to impede the moisture from leaving the wood, and if dried too fast the wood will check." http://www.rexlumber.com/lumber/species/oak-white
_______________
4/4 comes out of the kiln in 30 days while 12/4 timbers require some years to season. Lumber yards are often unable or unwilling to let stuff sit around and stew for that length of time and have been known to accelerate the process by bending their own established schedules.

The truth is, buying and using boards thicker than 8/4, is a real crap-shoot for some materials and particularly oak. It's a gamble which I'm unable to accept and there's no reason why I should since laminated wood is "solid wood" too and dimensionally and structurally superior.

The best thing you can do then with 12/4 oak is to re-saw it before using it or return it to the yard.

I've had pallets of 16/4 oak newel posts which had to be dumpster-ed due to honeycomb checks and twisting and warping after turning.

So yeah, I'm stodgy and opinionated.

From contributor Ca


Hopefully, the Wood Doc will weigh in on this one.

One item I'd like to comment on is the discussion of how much the door would "move" ... if it's frame and panel construction, my understanding is that it's really only the outer stiles that contribute to a change in overall width of the door.

From contributor Ge


First, if the wood is casehardened, that means it will move immediately when it is machined. Casehardening affects no other items. So, casehardening is not an issue here. In fact, it does put some question on the comment from your supplier and his in-depth knowledge.

Second, when measuring the MC with a pin meter, use only those made in the USA, as they will have the correct calibration. Also, make temperature corrections, as the meters are designed for 70 F. For every 20 degrees that the lumber is cooler, you need to add 1 % MC to the reading on the meter. White oak does not need a large species correction.

However, when checking the MC of a thick piece, always use insulated needles that have only the tip exposed. That will give you the MC at the depth where the tip is driven. (The insulation must be intact.) If you do not have insulated needles, you can rip of crosscut the lumber and expose the inside and then use the needles on this freshly exposed surface.

When stickered material is left on a cool warehouse, the ambient conditions are 11% EMC, which means the surface MC will reach 11% MC. The core will take much, much longer and, in fact, may reach only 13% MC after a long time. Even if the wood is stored inside at 40% RH, which is 8% EMC, the shell may be that dry eventually, but the core will be somewhat wetter. When you begin to plane this lumber, that will remove the dry shell and so you will see that the MC of the lumber increases, on the average. In fact, the exposed wetter lumber, after planing, will often end up cracking a bit.



From contributor Ge


Now, let's talk about in-use MCs. In most of the USA, the outside humidity averages 65% RH. This is 12% EMC. So, wood exposed outside protected from rain and sun in most of the USA will be at 12% MC.

This is the MC of a door that is not subject to direct sunlight or rain. Obviously, rain (or lawn sprinklers) will increase the MC and direct sun will lower it. A storm door will increase the heat and prevent wetting, so the door will be drier. So, it will tend to balance out so that a door will be around 10-11% MC typically on the exterior. Note that the RH is the same winter and summer, even though our bodies try to tell us differently.

The interior of most houses in the USA runs around 30% RH in the wintertime and 50% RH in the summertime. This is 6% to 9% EMC. So the inside of a door will be between 6 to 9% MC. Excellent finishes will slow the rate at which the MC changes, but not stop it or change the ultimate values.

Finally, let's consider what the wood does when the RH or MC changes. First, if the door has been dry and now it is exposed to a higher RH, there will be a lag in the wood's response. In other words, we might expect that a change of 5% RH will have no effect at all. (Technically speaking, this is called the hysteresis effect.) Plus, if the change in RH is slow, the wood will actually give a bit and the amount of movement will be less than predicted. [as an aside, sometimes furniture, cabinets, doors, millwork, etc. is at one MC and then brought into a home that is considerably drier than the previous RH, such as the RH in a shop or in a storage warehouse. This results in a rapid change in MC and rapid shrinkage, which is turn can mean warp and cracks. A slow change, such as we see annually is not a big issues compared to the fast change.]

Quartersawn white oak (if perfectly quartersawn with the rings at 90 degrees to the surface, moves 4.4% to 6/6% from green to oven dry (0% MC). This variation is due to variation within the different white oak species. The larger the piece of wood and the slower the change, the less movement. If we divide the numbers by 30%, we get the movement of quartersawn white oak per percent MC change...that is, 0.15 to 0.22% change in size for a 1% MC change.

So, for example, a 3% MC change, we would expect a change in size for a 40" wide door to be (considering the hysteresis effect and the reduction due to the large thickness) about 40 x 0.0015 x 1.5% MC = about 1/10 inch.

However, this is across the grain movement (the width of a piece of lumber). The length does not change when the MC changes, so if this door has horizontal pieces running across the top, bottom and maybe the middle, these will tend to stabilize the door even more.

The bottom line is that a door at the correct MC will not move much at all. The problem in almost all cases is that the door, when manufactured or installed, is not at the correct MC.

Questions?

From contributor Ji


I've worked with a bit of 12/4 KD ash, maple and cherry. I know the rules of moisture and shrinkage and know what to expect.

Except it doesn't. Wood that has acclimated for several years shows a disturbing tendency to move when milled or when placed in service.

My take-home on this issue is that I can think a problem is solved a lot quicker than Mother Nature solves it.

Laminate, because sweet dream waiting on a nightmare is the perfect description.