Needing some advice on lumber moisture content

[Fyrme]

Man I miss this place. someday I hope my life slows down enough to frequent again. But for now, speaking of work, I need some advice on moisture content of rough sawn pecan that I have drying in my loft at the moment. Over the early winter I picked up some Pecan logs that I had swan into boards. Prior to being sawn, they had been cut and laid piled up outside with bark on for around 6-8 months.

When I brought the boards home they were at about 26% on the moisture meter. They have been stacked in the loft separated with stickers in my non climate controlled shop. I am currently down to 17%. Which is the same as the kiln dried pine 2x4's next to them. Living in humid Oklahoma, I'm thinking 17% ain't to bad for only a few months stored in a "dry" location. But I don't see them getting much drier in this location.

I've read that around 6-8% is good for furniture. And technically that's what I'll be building with some of it this fall. However, this project will for the majority of it's life, live in a different non climate controlled shop here in NE Oklahoma.

Before I ask my question(s), I need the wood to be available by the first part of August. I've looked around for a place to kiln dry it for me, but the VERY few places with a kiln around here does not have the time to mess with my wood, because they are too busy with their own.

With that said, should I use it as-is? Or take what I need for the project inside my house and store it? The latter being a huge PITA. One other option I've pondered with is wrapping the area of trusses the lumber is stored with plastic, buying a fan and dehumidifier and try to dry it out where it sits. Another PITA, but doable.

As I said, the furniture will live in an environment much like what it's in now. If this project was going indoors, I would know better than to even ask these questions.

 

[Marctrees]

Fyrme - With your attention to detail... having a glimpse of the reality of wood movement...Highly suggest you get a copy of "Understanding Wood" by R. Bruce Hoadley.

Among serious level woodworkers, this is the Bible on this subject.

You current MC MAY,,, May be suitable for your project IF your joinery details take it into account.

Reading your post again, "As I said, the furniture will live in an environment much like what it's in now. If this project was going indoors, I would know better than to even ask these questions."

It sounds like you have approached close to equilibrium for your long term use location, so you are safe.

Marc

 

[Marctrees]

Again, in diff words... "6-8%" is ONLY true if that is the long term equilibrium where it will be long term.

In most geo locations, you will have MC gain hence expansion and possible problems if thats the MC you build it at.

Marc

 

[Marctrees]

Realize that typical SYP or SPF "Pine" both one and two by at lumber yard are Kiln dried to "19%"

NOT lower.

Marc

 

[strutaeng]

Marc, I'll have to look up that source you listed.

Another excellent source is one by USDA. I thought it was the gospel on the subject...maybe?

I have done some furniture some time ago, and never bothered to check M.C. The lumber was mostly cherry from a local hardwood suppluer in the area. Mostly, you have know the basic mechanics of wood expansion/contraction and allow for this.

Now, as far as lumber is concerned, for kiln dried that M.C. is 19% for dimensional lumber and 16% for engineered lumber.

I looked at an old 1920s building where the owner was concerned about water damage. It did have a lot of water stains, but my conclusion was that it was likely old water stains. My readings for MC was around 11-12%. I seem to remember the Equilibrium Moisture Content EMC for most of the US was around 10%, so very close to my readings. I think this came from that USDA source.

Obviously, SE Gulf US will be higher than the desert SW, etc. Use your judgement here.

I hope this helps you.

 

[Marctrees]

I had said " It sounds like you have approached close to equilibrium for your long term use location, so you are safe."

After re reading, I'll subjectively change that to - You would be better if it was a bit drier, but probably OK... but also depends on your joinery techniques allowing a bit o wiggle.

One guy's opinion.

Marc

 

[Milton Shaw]

You are probably Ok on moisture levels, but make sure you put as many coats of finish on the bottom side (hidden) of your wood. This make sure the wood looses and gains moisture the same on both sides. This keeps the wood flat and makes the wood be a lot more stable regardless of moisture content.

 

[Fyrme]

Thanks for the replies fella's. Marctrees, I'll look up that book. I don't do a ton of woodworking, but I do enough that I need to understand things like this a little better. As far as my joinery on this project, it is still a bit early to determine those details just yet. It will however be a "rustic" build. Thanks for the tip Milton, it will be heavily sealed to withstand some outdoor use at times.

 

[Kaizen]

Chad.....are these sawn to 1" thickness? Hopefully the ends were sealed when cut or i bet you have some splitting.
What are you building? I'd be concerned if you are making a table 4 feet across or even a big bureau top. I know you say rustic but lots of different ideas of what that means.
Depending on the joints you are making it will show eventually. Kind of like how trim in a house or doors show gaps in winter and swell in summer. But this will make a gap that will not close.
just a fan around the stack will increase the evaporation but not sure if it will do that much in the next 3 months. adding a dehumidifier might be detrimental at this point as it will be taking the moisture away too quickly. so the center will be wet but the ends will dry and crack. If you have a dry basement you can put it in to that conditioned space which will dry a little faster then out in the air of the shop.

 

[KenC]

I have some walnut in my shop, up high on racks. It's been there for years or so. After a year it got down to 10-11%. I've checked it a few times and it follows the season. spring 12-13, late summer 10 or so. Some of it has been used for furniture, inside use, over the years with no issues. Haven't check the MC in a while as I lost the probes from the meter.

 

[WVBrady]

You are probably Ok on moisture levels, but make sure you put as many coats of finish on the bottom side (hidden) of your wood. This make sure the wood looses and gains moisture the same on both sides. This keeps the wood flat and makes the wood be a lot more stable regardless of moisture content.

A common demonstration of this is with paperback books with a glossy cover. Typically they will draw moisture on the nonglossy inside and curl outwards.

 

[FTG-05]

I would think an expedient kiln could be "made" by simply storing the wood in your attic. Of course, this would depend on the size of the wood in question, how much wood and how accessible your attic is.

Not feasible? I would build a simple solar powered kiln; large wooden box, paint flat black, install a small or two. You'd have all summer.

Good luck.