my lumber store carries alot of wet wood
hartproject | Posted in General Discussion on
I’m not sure what I’m supposed to be doing. I feel forced into buying 11 to 13% MC hardwoods because that is all my store has sometimes (they say its appropriate because their store is 9 to 13% RH. Well fine, but I have to work with it right away and a lot of my table tops keep warping within a week of gluing them up. Is there no way around the trial and error, do I really have to wait until the wood is between the recomended 6 to 8%. I already know the proper table top gluing techniques and I know the difference between quarter and plane sawn. Its just got to be the moisture release, right? Anybody?
Replies
The only time wood is at 4-5% EMC is right after it is taken out of the kiln. As soon as it is exposed to the outside, it begins to acquire moisture until it equalizes with the relative humidity in which it finds itself. If the environment is at 75% relative humidity, the wood will get to 10-12% EMC. There is nothing your supplier can do about it.
What is the relative humidity in your shop?
Unless you are in Arizona or some other exceedingly arid area, you will never get wood to stay at 5-6% EMC.
All the hardwood that you buy here in Houston is at the 15-23% EMC cause none of the hardwood yards are air conditioned and the relative humidity rarely gets under 90%.
You learn how to pick your lumber out of the stacks and how to allow for expansion/contraction when building. I look for the straightest grain I can find, preferably running the full length of the boards. When using it, you presume every board is going to move in the final piece.
In other works, like the Retrosexuals - you deal with it! (visit the cafe)
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
I have to work with it right away
Dude...
That's asking for trouble no matter what mc the wood is at when you get it into the shop.
do I really have to wait until the wood is between the recomended 6 to 8%
No, you need to let it acclimate to your shop. Whether that means 6% or 10% depends on the humidity in your shop (heated, cooled, season,...). Next time you get wood, give it a week or two and keep track of mc with a moisture meter. No meter? Let it sit for 2-3 weeks, cut to rough size, let it sit another week, then cut to finish and assemble. The longer you can let it sit, the higher the chance it's at equilibrium.
To follow up...
4-5% EMC (equilibrium moisture content) of lumber requires the relative humidity of the air to be BELOW 25%. This RH is only typical of arid (desert) conditions and heated, unhumidified cold climate homes during extreme cold. Otherwise, a more reasonable and more middle of the road EMC is 7-10%.
I will agree and reiterate that you should purchase lumber and then let it acclimate to your shop conditions prior to working it. It is dry and stickering is not a requirement - BUT - stickering your boards will let them acclimate more quickly than stacking them on top of each other. Another thing you can do to more quickly acclimate are to skip plane the rough lumber right after coming to the shop.
For certain, once lumber is milled and you are in the middle of the project, it should be stacked and STICKERED if you cannot cut the joinery and assemble in a single day. My guesstimate is that 90% of glue-up panels warp because they are left to dry overnight without adequate air access to all sides of the panel.
Of course, all this assumes you've done the other basics to ensure minimal warpage - selected good boards to begin with, planed off roughly equivalent amounts from both faces....etc.
A classic case of a little bit of knowledge being a bad thing..
Others have pointed out how the relative moisture changes the level of moisture in the wood..
My solution is to climitize a whole lot of wood.. Inventory enough wood for your needs and you wont have the problem, buy it as you need it and pay the price..
Find a sawmill and buy a large quanity of the wood you like,(if you buy enough you can get it whiolesale which will really make this attractive) , meet up with some wood workers and trade your surplus for theirs..
A bunker of say, white oak will sell for $800.00 (that's a thousand bd.ft.) trade some of it for some walnut and birch and cherry etc. and you'll wind up with around 600- 700 bd.ft. of a variety of wood.. at much less than half of what you currantly are paying.. Since your's are the first fingers to walk through the pile of boards, you can set out the really special pieces and trade off the rest!
The cost of being the rugged invidual just went up!
Frenchy,
I've learned a lot from this forum but the ONE thing that's really made an impression on me and I would really like to emulate - I would like to some day buy lumber at "frenchy" prices. After years of paying too much, this is my one major goal in woodworking. I'm getting better - I had a good March and April. Got a bunch of free white oak, pecan and hickory from pallets in March (short, 2/4, and a mother-bear to get the nails out, but free) and in April I bought over 100 bd ft. of 30-50 yr. old air dried walnut for $3.00/ bd ft, and over 100 bd. ft. of year-old air dried aromatic cedar for $.45/ bd. ft., with the option to buy 700 more bd. ft. of that cedar (How many blanket chests can you make?). I'm not down to "frenchy" prices yet, but I'm getting closer and closer. <G>
Keep telling us the secrets of finding cheap lumber!
Ed
You were so close to the source!
Pallets! that's the hint! they need to be made out of hardwood to get a GMA rating (trust me it's a good thing) that hardwood comes from a source. find that source and there's your cheap lumber!
Ed, I just old a fellow 55 bdft of wide Magnolia and 50 bdft of spectacular Red Bud for $110.
He happened to come by while I was sawing and I'd much rather throw it in his truck cheap than haul it to the shed, sticker it, dry it, unsticker it and then sell it to him for just a little more.
;-)
Wher in MS are you?
I am in East Central Mississippi. I didn't know you could use either of those species for furniture or cabinet-grade, but well, what I don't know, could fill volumes.
I am kind of on the lookout for native species that I can use for furniture and cabinet-grade. On the lookout for a couple hundred board feet of pecan, in particular.
The guy I bought the cedar from cut it, milled it, stickered it, dried it, all on his own property.
Do you have lumber to sell? I occasionally get up toward Memphis. I will probably be spending a few weeks up at Oxford (University of Mississippi) this summer.
Take care,
Ed
Ed,
One of the really cool things about having your own sawmill is being able to saw lumber that commercial mills wouldn't ordinarily saw due to lack of volume, markets, etc.
We airdry cedar on our own land as well--it only takes a month or so in the summertime and doesn't require kilning. Hardwoods we will airdry at our place first and then take to a kiln for final drying.
We will be sawing and drying a couple 1000 bdft of Pecan this summer. If you'd like I'll put you on my notification list and let you know when I have some ready.
That would be excellent. Will respond by private e-mail with contact details.
Ed -
Questions for you. Which lumber would be best to use for furniture? Some that has been air drying in a shed for 3 or 4 years, or some that was air dried first, then kiln dried to 8%, and lastly set beside the other lumber for the last year. All stacks are stickered. The shed is not heated or air conditioned. Consider the lumber equal in all other respects.
And the last question is - why?
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
Just in case I'm being called Ed ;-),
If I had wood in my shed for 3-4 years it would probably average 13-15% MC. The stuff that went to 8% at the kiln would probably come back up to 9-10% in the shed in no time. Probably wouldn't go much higher though since kiln dried never seems to make it back up to full EMC.
If I were to use all the wood in the same project, I'd try to use the once KD stuff for pieces I was cutting joinery into and use the AD stuff for floating panels, applied trim, etc.
The AD wood is going to shrink when it comes back in and it's shrinkage will be easier to accommodate in one dimension. The KD wood won't shrink (or expand) as much as the AD and wouldn't risk as much in terms of failed joints.
If you were wanting to bend anything use the AD--it's much more supple.
Oops, I was looking at Ed's message. Sorry!
>>Probably wouldn't go much higher though since kiln dried never seems to make it back up to full EMC.
Now, that is something I've never heard before! Why would that be?
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
I'm not sure, but I've left KD stock in my carport for months and it never seems to come up to the same MC that stuff I'm airdrying comes down to.
I'm sure there's some scientific explanation but I've been to busy to find out what it is.
;-)
Memphis (got it right this time)
I have always felt that the only reasons to kiln dry was 1) to speed up the drying process, and 2) to find the bad wood if dried down to the 6-8% range.
I personally have not observed any mechanical differences in the wood properties when using air dried vs. using kiln dried if used at the same EMC. Everything I use down here in Houston is in the 18-23% EMC range regardless of whether it was kiln dried or not.
Well, I take that back. Sometimes air dried wood will develop checks when moved inside in an air conditioned environment. Something that would have already happened to kiln dried wood causing one to reject those pieces beforehand if discovered in time. I guess if the wood is going to check or cup, kiln drying will find those pieces and allow you to reject them.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
One real advantage of air dried wood over Kiln dried wood is lack of stess..
Kiln dried wood can and sometimes does develope what is called Case hardening.. That is where it was never conditioned after drying to relive the inherant stresses of rapid drying..
another thing less sommon with kiln drying is called honeycombing.. where the wood sort of hollows out and becomes extremely weak..
I've seen as many bad things happen to kiln drying as I have to air drying.. Kiln drying simply gets the wood ready faster.. If it's your money tied up, you'll want to kiln dry so you get paid quickly.. If on the other hand you are paying the bills and worry more about cost than spped well air dried is simply the way to go..
I prefer to work with air dried (AD) wood--less stress, richer color, better response to tools and more supple.
Honeycombing is not a problem with AD as long as it is dried in an appropriate location--10/4 Walnut slabs need a shady spot with very little breeze and a long time; 5/4 Cherry likes shade, a little breeze and a summer; 4/4 Eastern Redcedar wants a couple months wherever you put it the summer, 3 months in a sunny spot in the winter.
Once it's 20% it can come into (stickered) a 10% EMC shop, hallway or livingroom and hang out until it's ready for it's final home. I build most of my stuff at 10% (that's where my shop is at) and work into the design what's needed for where it will eventually live all oiled and waxed. Sometimes I will work freshly kilned wood (7-8%) but only if the location I'm building for demands it or it's all that's available.
There's also no cure for PPB infested wood like a hot kiln for a couple days.
My experience in furniture restoration tells me that far more damage occurs from furniture gaining moisture and (then loosing it) than loosing it to begin with.
IMHO, kiln drying's popularity is much more a matter of convenience to mass producers than any relection on a skilled woodworker's ability to anticipate the movement of his/her medium.
Memphis,
Agree.....a BIG advantage of kiln-drying - it kills any problems in the wood, be they insect or microbe. I like to visit a few places that specialize in turning urban trees into lumber....and most often, those trees are felled because they've contracted some sort of disease or infestation....wouldn't want that lumber unless it was kiln-dried.
But then again, I've got some air-dried black walnut that ABSOLUTELY is gorgeous....and would look just ordinary had it been kiln-dried.Tim
A lot depends on the type of wood.. for example Black walnut is always much more colorful if air dried than kiln dried.. However hard maple is so finicky that I would rather have kiln dried..
Wood that is in a shed is the same moisture content no matter wiether it was air dried first or not.. leave a chunk of wood anyplace and it will eventually stalize to the moisture level of where it is..
There is no magic benefit for visiting a Kiln..
One of the sawmills that I sell to has an open "kiln" they shove a railroad car full of wood in one side and as quickly as possible pull it out the otherside. Because of that the stamp KD 19 on it and sell it for more than the same wood sold SD19..
Do you know the differance? (KD stands for Kiln Dried to 19% moisture while SD stands for Shipped dried to 19% moisture..) Most soft woods will quickly dry to 19% moisture content just by being cut and standing around while it's sorted/ stacked bundled and hauled out of the sawmill.
If they haul it through a kiln (evan if the kiln isn't working) they can stamp the KD label on it.
Flatsawn wood, even after it has adjusted to the relative humidity of your shop will still unavoidably cup slightly with seasonal changes in moisture content, so expecting the top to stay perfectly flat, even if you do everything right, is unrealistic. There are various strategies in cabinetmaking for minimizing and coping with the problem but it would take a dozen pages to cover the possibilities.
I'd suggest getting Bruce Hoadley's book, Understanding Wood. After reading the couple of chapters on wood movement you will have a much better idea of what is happening and why.
John W.
Travel a bit further and buy your lumber elsewhere. In large quantities like frenchy said. Usually at 1,000 bd ft you get a price break anyway.
Okay, I may be starting something here but... I think the company that you are dealing with may not be doing all it should. Sure, from what I see in the numbers it looks ok but often times hardening, underdrying, and overdrying of wood are direct backlashes from poor company management, poor equipment maintenance, and lack of proper recording.
Unless lumber is properly assorted before drying, some of the moisture reads will be inconsistent. I suggest doing a search for other alternative suppliers. Hope this helps.- Mic
This forum post is now archived. Commenting has been disabled