How dry is dry?

[max_in_graham]

I've got a good bit of red oak, cedar, walnut and some maple that was taken down on our property. I had it sawed into 4/4, 5/4, 6/4 and a couple of 3" oak slabs. (and a couple big slabs of cedar)

I stickered it and let it air dry in what was to become my recording studio for about a year. A friend needed a place to store a 43' trailer. I restickered the lumber in the trailer for about another 12 months. It found its way to an already crowded basement for the last 18 months.

The oak and cedar seemed to have dried much quicker than the walnut. So when I moved the lumber to the basement, I stickered the walnut and flat faced the rest of the lumber on top.

Needless to say, after almost of 3 years of wide temp variations, not all of the lumber is perfectly straight nor free of warping or checking. Which I think is going to be fine since I will be milling from 4/4 to 3/4 and 5/4 to 4/4.

I was wondering if I would benefit from having the lumber kiln dried at this point?

The majority of the lumber will be used as "paneling" in the studio and will be finished smooth and polyeurothane on all 4 sides.

As a side question... is there a way to test moisture content w/o a meter? My guess is that I should go ahead and get one... (oh darn... a trip to Woodworker's Supply)

Thanks,
Max

 

[woodnick]

IMO too dry is as bad as not dry enought!!!

 

[DaveO]

If the wood is going to reside in a climate controlled environment I would either have it kiln dried or pay particular attention to allowing for the wood to move, especially shrinking. Air dried lumber in our climate might get down to ~12%, a climate controlled interior environment would have and EMC of between 6-9% (based on 35-45% humidity).
This is a helpful link to determine how dry lumber needs to be for the application - http://www.csgnetwork.com/emctablecalc.html

If you can store your lumber in the environment it will reside in for a few months, it will reach EMC with that environment and then the only advantage you would get from kiln drying is time savings and control of any bugs that might be present in the wood.
There really isn't any easy way to determine MC without a moisture meter. You can weight a sample of the wood that is stored in it's final home, and once is stops losing weight it has reached it's EMC. But that takes some pretty precise scales and careful record keeping...not exactly easy.

MTCW,
Dave

 

[Tarhead]

Howdy Max! Welcome to the group.

What Dave said and here's some additional thoughts:

Storing it inside may have slowed that 1"/yr rate down but it depends on the ventilation and temperature. Storing it in the basement w/o a dehumidifier will probably not accomplish much or may increase the moisture content.

If he doesn't reply to this thread, send a private message to Scott (scsmith42) and check w/him. He is near Pittsboro/Apex and has the closest kiln I'm aware of that will do small loads and he really knows his stuff. He's a great guy too!

If you don't have access to a moisture meter you can do this:

I've never done this in your oven so if it stinks up your house don't whine to me:gar-Bi. You will need a very precise scale (postage scale is what I use) you can weigh a small piece (~1lb) of each species of your wood and then spread them out in the middle of the oven overnight on the lowest setting. Then weigh them in the morning and figure the percentage weight loss after drying. That should get you very near the numbers you will get with a meter you can buy for under $100. Don't buy the Harbor Freight moisture meter. I'm on my 5th one and they're just junk.

You can make a dehumidifier kiln by re-stickering/re-stacking, enclosing the stack with a plastic sheeting cover and hooking up a dehumidifier in it with a drain hose coming out of the enclosure. Be sure to spread the plastic under the stack or you'll pull moisture up through the floor.

I would definitely get a set of ratchet straps and clamp the stack real tight. You may be able to take some of the twist and warp out if it's still not dry.

Good luck!

 

[Mike Davis]

Don't buy the Harbor Freight moisture meter. I'm on my 5th one and they're just junk.

The definition of insanity is doing the same thing over and over and expecting different results. :rotflm:

 

[Tarhead]

The definition of insanity is doing the same thing over and over and expecting different results. :rotflm:

To quote the title of one of my favorite albums from 1971:
"We're all Bozos on this bus.":gar-Bi
Sometimes things with batteries at Harbor Freight work out...like my digital calipers but I've learned my lesson on the moisture meter. Some days it works, some days it doesn't.

 

[Travis Porter]

Personally, I would use it. I cut 5000 BF of white oak in 8/4 and 4/4 and let it dry in a tobacco barn and have had zero issues with it after letting it dry for 3 years. Put whatever you are going to use in your shop for a week or so, and go to it. JMTCW

 

[max_in_graham]

The place is definitely going to be climate controlled.

I just finished the framing and I'm waiting on the HVAC and Electrical to get finished, so I can button up the walls... 3/4" MDO, 2 layers of 5/8" Fire Rated Gypsum, then a 1" layer if Owen Corning 703 rigid insulation/furring strips. The final layer is the finished lumber; 2", 4" and 6" boards that get gapped/spaced at specific distances.

Once I start the process of closing in the walls, I'm pretty sure I still won't have a permanent connection of power to run the HVAC on a constant basis. So I imagine it's goint to have a tendency to get pretty warm and potentially either really dry or really humid. Mainly because the rooms are completely air tight, except for the HVAC.

I go through all this detail because I don't want to move the lumber to let it acclimate to the rooms the lumber will be used in, if all I'm going to do is create more problems with stability. In other words, I don't wanna' move it too soon, nor too late.

I'm probably being an overly paranoid worry wart, but this is a life long dream that Ive put way to much time and money into to blow it on the finish stage. Should I try to plead with the building inspectors to let me wait for/or get early permanent power before finishing the lumber?

Thanx!
Max

 

[Tarhead]

Max,

I would try to figure out how dry the lumber is to start with and then go from there. I've never done paneling but I imagine doing it w/wet wood is asking for problems with cracking/splitting, etc as it dries and moves. You can follow my procedure above to check it or go get a good moisture meter. You could also take samples of your lumber (get it from the middle of the board in the middle of the stack) to a cabinet shop, The Hardwood Store in Gibsonville, etc. that has one and see if they will check it with their MM. Travis' situation was optimal in a tobacco barn made to dry tobacco. It probably had very good ventilation and got warm in the summer. Storing your lumber in a trailer w/very little ventilation and then in a basement where I imagine your average humidity level is high and ventilation is nil may not have accomplished very much drying. If the wood is dry do the paneling last after you get power to the HVAC. Stack and sticker it w/a fan blowing on it with the A/C running for as long as you can to acclimate it. I did that with Red Oak flooring for a week and have had no problems.

Another thing you need to do is look for tiny piles of sawdust in the stack. Maple (especially Red Maple) and Oak are beetle magnets in my experience. If you have bugs you'll need to deal with it. Kiln drying is one way to do it.

Mark

 

[jeff...]

IMHO Lumber for outdoor use should be 12~15%, for indoor use 6~10% - A dehumidifier really helps bring a small air dried stack into an acceptable indoor range.

 

[max_in_graham]

Thanks for the advice!

Well, it sounds like I'd really be better off knowing how much moisture content is in the lumber.

Gonna' make the dreaded trip to Woodworker's Supply (darn it! :gar-Bi) to get a moisture meter, sometime this week.

Anyone want to suggest a good meter or two to look at?

I figure that the cheapest one they have will be just that... cheap. And while the most expensive one is probably a fantastic meter, I'm sure it'll be serious overkill for my use.

Thanks!

 

[Mike Davis]

Two further points to consider.

If you are spacing the boards apart? Does it really matter if they shrink, I assume you want to space them to reduce echos?

When you put up the paneling/boards nail in the center only. If you have two nails, one on each edge, then you lock in a width and then when the board shrinks it will split. If only nailed in the center then the edges are free to expand and contract, no splitting.

 

[max_in_graham]

Mike,

The spacing is primarily there for a specified amount of sound absorbtion at calculated frequencies. The added benefit is that it also helps to control what is called RT60, or the amount of time it takes the sound to decay by 60 percent. RT60 is one of those goofy scientific names for reverberation time.

Echo's are a bit different than reverberation... but the result of the spacing is still the same... the spacing should prevent any echo's at all.

Actually, the spacing is fairly critical. The overall spec is 1/4" variation over the span of any wall.... and there are a couple of walls that are 17 feet long, one that's 21 foot long and one wall that's 26 foot long.

The spacing between the boards is what actually helps to "tune" the room to certain frequencies. If that spacing changes by say... 1/4" per board... the entire sonic characteristic of the room changes. That can seriously impact how the music sounds. So, it's pretty important that the wood is as stable as it's going to get.

Here's a pdf that shows what I'm up against...
http://www.dmmobile.com/blog/wp-content/uploads/2008/05/a-3.pdf

Is this insane?


YOU BETCHA! :BangHead:

 

[Mike Davis]

In that case I would mount the wood on T-tracks so they can be adjusted as required, no wood is going to be that stable over a long period of time. By mounting the boards on t-track you can re-tune the room.

 

[scsmith42]

Max, lot's of good advice from others in this string. As usual, DaveO hit the nail on the head (and Mark - thanks for the kind words!).

After 3 years, your lumber should definitely have reached EMC with it's environment. To know for sure, buy a good meter. Delmhorst has a great reputation, and you can't go wrong with one of their products that's designed for wood. There are some great strings on NCWoodworker that delve into the pro's and cons of different meters, so I won't go into detail here.

Depending upon the original logs, it would not surprise me that your lumber has some warp, checks, twists, etc. This is where a really good sawyer and high quality logs make a difference; almost moreso than the drying process.

If it were me, I would not be afraid to use your AD wood, but I would suggest two things. First - buy (or borrow) a good meter and see where you are at; you'll want less than 10% for interior wood. Second, store the wood in a warm, dry location (such as an attic) to help it complete (or maintain) the drying process.

Wood seems to regain moisture easier than it loses it. So, from what I've seen, for flooring or paneling it is slightly better to have wood that is a little bit dryer than your EMC, and allow it to raise it's MC% slightly to match EMC in the room prior to installation, versus having wood that is greener than the EMC and and expecting it to dry completely down to EMC in the house for a few weeks.

Ditto the recommendations to look for evidence of any insects. If you find evidence, definitely have the wood KD and sterilized before installing.

In your application, I would definitely have power and HVAC installed before moving the wood into the location, and allow it to acclimate for several weeks before installing.

Scott

 

[max_in_graham]

Scott,

Thanks for the info!

Considering how much of the building is wood... I will absolutely be checking for bugs!

I've gotta head to Greensboro for some fire caulk today, so while I'm out and about I'll stop and look at what WW Supply has... (I love and hate going in there... I'll spend too much money I know!)

 

[max_in_graham]

I've picked up a Delmhorst J-Lite moisture meter. I think it'll be a sufficient
meter for my needs... hope so anyway.

I did some random checking in the pile and most all of the wood has reached between 9 and 9.5 percent. (Allowing for temperature and species)

Unfortunately, with the lack of space to move the lumber, it's going to have to sit in the basement for at least another couple of weeks until I get my rough-in inspections done.

At that time, I'll move the stack to the studio to get the moisture content down as low as I can before starting to work with it.

There won't be a permanent power connection for several weeks after that, so sitting in the heat of the building should help to drive that moisture down another point or so.

If nothing else, maybe I can put a dehumidifier next to the pile to help draw out more moisture.

Again, thanks for the advice gentlemen!