Acclimating Lumber

[Ken Krawford]

I'm getting ready to build some cabinet doors out of red oak. It is kiln dried of unknown moisture content. My shop is 70 degrees and about 55% relative humidity. The doors will be 2" frame and panel with the largest door being 27x18".

I know there's not an exact answer, but how long would you leave the lumber in the shop before fabrication?

[Carl Beckett]

2 weeks. With some airflow around it.

[Cody Colston]

I agree on the two weeks of acclimating. 70 degrees and 55% RH equates to a 10.1 EMC. You might want to pre-finish the panels before glue up as they will likely shrink in-situ.

[Keith Hankins]

I'll ask a couple questions since the answer could be Depends. First, the cabinet doors they in your house, and I'll assume yes. Second, where's your shop, garage or basement or barn? Third, what part of the country are you in, is it stable humidity over the year or do you have regular seasons so humidity fluctuates. Finally the door rail/stile material flat or Q-sawn. My shop is in my basement and I live on the east coast again (was in the mid-west for 4 years). For me a minimum 1 week before I start my milling process. I rough mill to close to final thickness sticker and set a week If it's not been squirly then i take it down to final and do my cope/stick and set another week. If you are not using Q-sawn (trust me you don't Save $$ in the end) all bets off and I'd go more leave it fat because it's gonna move. When I lived in the midwest I experienced more movement due to H changes. Not as bad back here on the East coast. Good luck and be sure to post some pic's we all love wood porn

[Jeff Heath]

The absolute correct answer is......until it reaches equilibrium with your shop conditions. Sometimes, it can take longer than a few weeks. Unfortunately, you'll find out the hard way if you flatten and plane some stock, and find it looking like a banana the next day.

55% relative humidity in your shop is considerably higher than 6% to 8% MC in kiln dried wood. 35% RH would be more like it.

Red Oak can and will be one of the species that air dries much slower in your shop than maple, cherry, or walnut. In fact, I can tell you from a lot of personal practical experience that red oak can be one of the more difficult species to deal with when it comes to air drying.

The best way to be sure is to have a moisture meter to check your wood. I know that $100 or so is a lot of money to spend on a good meter, but think about having $300 of firewood if all your wood is worked by you before it's acclimated, and it warps, twists, and bows.

Only way to be sure......measure it.

Jeff

[Jim Neeley]

Another hint is to acclimatize it in the area it will be installed, if possible. For example, if building an entertainment center, under the couch is an option... if the bride will permit it.

[Danny Hamsley]

Exactly. Behind the couch is a popular place for wood at my house .

[John Shaffner]

About seven years ago, I started the design phase for a Mission style bed for LOML and me. We decided on cherry so I gathered what cherry I had stored outside and brought it into the shop to "acclimate". Being some of it was over 2" thick, I figured maybe a month would do to get it to emc. Well, that was seven yrs ago and it still sits up in the rafters, rather what's left of it...I used most of it for other projects and never did get the bed built. LOML askes every so often if it's still acclimating and my reply is usually..."Yep, not quite ready yet"!

[Mel Fulks]

The kiln dried is the key. In commercial shops having only exterior under roof lumber storage it is still pretty common to just bring it in and start work. Telling a customer you can start the job when the lumber aclimates would be like telling your girl friend you have bought the coal to make a diamond ring. The most we can do in winter is rough cut the lengths and push the carts into the warmest part of the shop overnight or for a day or two . This is where things like sprung joints come in...Fact is just getting shop temperature up to where you can glue is often difficult.On critical work I have moved glue ups into a company kitchen or office. I've told employers I had to have at least 55 degrees to glue and seen them point to a thermometer at ceiling height. Gluing while standing on a ladder is tough. Aclimation for air dried is nessesary .But we have all seen cracks in fine antiques. The modern eye will often accept flawless bad designs easier than flawed good designs. One good rule is never do work for anyone with a calloused nose.

[Jeff Duncan]

I like to let materials sit on my racks for a little while when possible....but as Mel alluded to, it's not always practical! What I do is base my approach on the product. So for interior doors I'll try to let the wood sit on the rack for a week or so whenever possible. Then I mill everything oversized and let it sit for several days while I work on other projects. This takes a little pre-planning, but I like to let the wood have a couple days to show it's hand. I'll then do the final milling and let my stiles sit on a cart for at least another day. Often the wood will move a bit after milling so you want to let it do so. Then I take my straightest stiles and set them aside and take any that have a bow to them and cut into rails. Anything with twist gets pulled and set aside for door stops or whatever. Using this technique I generally get good results from my stock....but even so every so often you'll have a stile move on you in service. You see....having the stock acclimated to your shop, or your house, or wherever is fine, but those conditions are going to change seasonally, and that's when the fun starts!!!

good luck,
JeffD