# Finishing wood slabs with 16% moisture, can I do it?



## Toomanyprojects (Nov 13, 2017)

Hello! I just got 3"Thick slabs that are 7' long and 24" wide a piece. I am planning on using them to make my counter tops. The thing is, is they are still at 16% moisture. I am planning on installing metal braces on the underside to control warping. I was also told that I could seal the top and sides with a polyurethane while leaving the underside unfinished so that it can release moisture through the bottom. Is all of this going to work? Counter tops would be awfully wonderful as they are the first step to me having a kitchen and not just a grill outside, but I don't want to ruin my beautiful wood and have to redo everything. Thanks for your wisdom!


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## a1Jim (Aug 9, 2008)

Welcome to Ljs
By using wood that wet your asking for trouble because it's still drying whether you finish it or not, Putting metal straps on the bottom which will cause your wood to crack because you will have wood movement and if it's restricted the wood cracks. Do some online research about wood movement to give yourself a better idea of what you're dealing with.

https://www.canadianwoodworking.com/tipstechniques/dealing-wood-movement

your idea of not finishing the bottom makes it so one side of the wood takes on more moisture the other ,straps or no straps its more lightly to cup. You want the wood to have the same amount of wood exposure finish one side then finish the other.


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## sawdustdad (Dec 23, 2015)

You don't mention the species or how the lumber was milled-is it flat, rift or quarter sawn? What species?

Knowing this will give you some idea of what to expect as far as wood movement as the wood dries. Quarter sawn will not shrink as much but if it includes the pith, it will likely check down the middle. If it's flat sawn, it's more likely to cup. Some species shrink more while drying than others.

I think if I absolutely needed to use this wet lumber to build counter tops, I would install it temporarily and let it dry in place, without any finish, with the plan to remove and mill it flat for a final install a couple years later. Or, just use some plywood until the lumber dries. Which, depending on how it's stored and your particular climate might take a couple/three/four years.


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## Toomanyprojects (Nov 13, 2017)

It's Doug fir, I don't know what flat or quarter sawn means! I live in a dry climate, in 10 days the slabs came down 10% in moisture content


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## a1Jim (Aug 9, 2008)

too here's some info on how wood is sawn

http://www.hardwooddistributors.org/blog/postings/what-is-the-difference-between-quarter-sawn-rift-sawn-and-plain-sawn-lumber/


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## a1Jim (Aug 9, 2008)

Now it may be safe to use and finish @ 10% ,8% is preferred but will still move some even in a dry climate.


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## AlaskaGuy (Jan 29, 2012)

> It s Doug fir, I don t know what flat or quarter sawn means! I live in a dry climate, in 10 days the slabs came down 10% in moisture content
> 
> - Toomanyprojects


How are you measuring the MC?


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## Lazyman (Aug 8, 2014)

> It s Doug fir, I don t know what flat or quarter sawn means! I live in a dry climate, in 10 days the slabs came down 10% in moisture content
> 
> - Toomanyprojects


It's very unlikely that a 3" thick board went from 16 to 10% in just 10 days. More than likely, it just the surface that has dried and not the entire thickness. That may takes months. If you are using a 2 pin moisture meter, you are really just measuring the surface moisture. You can test that by shaving some wood off the surface and testing it again.


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## Toomanyprojects (Nov 13, 2017)

Thanks for all the advice! What do you all think of finishing just the top and leaving the bottom to shed moisture?


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## BurlyBob (Mar 13, 2012)

What Jim said! Guaranteed they are going to cup, warp and twist..


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## johnstoneb (Jun 14, 2012)

You have a 3" slab 24" wide it is probably flatsawn, it will probably cup as it is drying. By finishing one side and not the other you increased the chances and the severity of the cupping. Finish does not stop moisture transfer it just slows it down. You need to go back and actually read and comprehend and heed the advice given above. and stack and sticker those slabs for 6 month to a year at the very least.


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## bondogaposis (Dec 18, 2011)

> Thanks for all the advice! What do you all think of finishing just the top and leaving the bottom to shed moisture?
> 
> - Toomanyprojects


That will almost guarantee cupping. You want wood to dry evenly on all sides. Your lumber is not ready to use.


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## bbasiaga (Dec 8, 2012)

Perhaps you can find someone with a kiln nearby that could dry them proper for you?

Brian


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## Toomanyprojects (Nov 13, 2017)

Thanks Brian! That is helpful advice!


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## jonah (May 15, 2009)

You can't "control warping". If you attach metal to the slabs, they'll simply bend the metal or crack (or a combination of both).

Wood is extremely powerful as it moves.

Get the slabs dried in a kiln or stack/sticker them for a year or so. With such thick slabs, they'll need a lot of time to come down to ~8% moisture content.


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## Toomanyprojects (Nov 13, 2017)

Thanks for all the wisdom! Now I know that working with wet wood is a no go. I found a place with a kiln that will dry the slabs for $60 a slab and will take 4 months, better than taking 3 years I think!


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## Lazyman (Aug 8, 2014)

Just realize that you may still get some pretty significant warping even in the kiln so you will still have to deal with that; it will just be before you build your counter top, not after. Note that the warping and cracking is worst where the rings near the center of the tree are so it can be minimized, but not totally eliminated, by cutting that out of the slab but then you are giving up some of the width that you want. If the slab goes right through the center of the tree for example, in other words you have rings that are full circles, cutting that middle part out leaves you with what is effectively a quarter sawn board which are generally the most stable. To tell for sure, the rings on quartersawn boards will run mostly across the narrow (3") dimension. when viewed from the ends of the board. This is good to know anytime you are culling through boards of any dimension at the lumber yard.


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