Stop Surface Checks?

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Chad Schmidt
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Location: Los Alamos, NM

Stop Surface Checks?

Post by Chad Schmidt »

Hi All,
I have a piece of ebony acclimating in my shop (unheated garage, high desert climate) that I'm planning to use for a Steve Kimock Cripe style solid body some day. I've had the piece for about 4 months and am noticing surface checks that were not there when I received the wood. The piece is 8/4 by about 7"x21" and is entirely coated in wax. Is there anything I can do to stop the checking? I'm debating resawing it close to planned thickness. If resawing is the answer, should I strip all the wax or recoat the fresh faces? Any recommendations on storage? I'm under the impression that stickering only helps with end checking. Lastly, any suggestions on how to prevent this in the future with other thick stock? Thanks in advance for any help offered; it would really make me sad to not be able to use this as guitar wood.
-Chad

David King
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Re: Stop Surface Checks?

Post by David King »

What's your relative humidity? It sounds like you are in an extremely dry spot. When I get ebony sealed in wax I have to assume that it's wet wood. I would wrap the wood in a plastic bag and check humidity levels inside the bag after a few days to see what's going on. Don't resaw to thickness yet. I'd consider sending the wood to a proper kiln (that knows ebony) if you intend on using it in the next 5-10 years

Chad Schmidt
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Location: Los Alamos, NM

Re: Stop Surface Checks?

Post by Chad Schmidt »

Thanks for the response David. I bagged the ebony tonight. At the time the RH in my shop was 19% on my digital readout. I put the monitor in the bag with the wood and will reopen in a few days and report back.

Chuck Tweedy
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Re: Stop Surface Checks?

Post by Chuck Tweedy »

RH in my shop was 19%
Yikes, that is scary low. No wonder the ebony was showing surface cracks.
Might want to humidify that a big before you check it up more.
That's a big piece of ebony by the way - well worth saving.
Likes to drink Rosewood Juice

Michael Lewis
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Re: Stop Surface Checks?

Post by Michael Lewis »

Ebony solid body? Going to be on the heavy side.

Wax sealed ebony usually responds well enough to resawing for thinner pieces like fingerboards and head plates, but your piece is rather thick for that. I would trim all the wax except for end grain and put the wood in a plastic bag and close it up. Each day remove it from the bag, turn the bag inside out, and return the wood to the bag and close it up. This gets rid of any water that condenses inside the bag, yet keeps the wood in a closed environment so it doesn't dry too quickly and check. This will likely take a long time to dry enough to use, and remember that ebony takes a very long time to dry anyway. Good luck, and you're on your own.

David King
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Re: Stop Surface Checks?

Post by David King »

One wood guy told me ebony dries about 1/4" per year.

Michael Lewis
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Re: Stop Surface Checks?

Post by Michael Lewis »

Regarding ebony drying, I have some blanks in my shop since 2000, they are about an inch thick and they are still holding moisture. They dry faster when they are cut into smaller pieces.

Chad Schmidt
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Joined: Fri Oct 19, 2012 11:52 pm
Location: Los Alamos, NM

Re: Stop Surface Checks?

Post by Chad Schmidt »

Thanks for the responses guys, that's useful info. I took the ebony out of the bag and my meter read 44% so the wood is obviously holding water. I rebagged the wood until I get a chance to build some sort of humidor in the next month or so. After that's built, I plan to patiently let it dry out; I'm in no hurry to build with it.

Regarding the humidor, it's something I've procrastinated on for quite a while. Do you use a saturated salt solution to maintain a fixed, known relative humidity? It looks like potassium carbonate holds at about 40% at the temperature range of my shop and seems to be right in the range of RH where most agree instruments should be built in. It's readily available from soap making suppliers...

Lastly, I agree Michael that an ebony solid body would be excessively heavy. The guitar I'm planning will be chambered with a thick top and thinner back out of the billet I have with lighter wood in between. Hopefully I can keep the weight manageable and the instrument balanced.

Again, thanks for the advice.

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Barry Daniels
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Re: Stop Surface Checks?

Post by Barry Daniels »

These aren't cigars. Wood should be dried to equilibrium with your shop which should be around 45% relative humidity. Wood in that state will have less than 10% water.
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David King
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Re: Stop Surface Checks?

Post by David King »

Another trick I use with wet wood it to measure across the grain with a digital caliper and record the width every few months. When the wood stops shrinking I know it's reached equilibrium. I realize a 24" digi-cal isn't everyday luthier equipment but you can improvise with a 1 foot steel rule and a 6" digital caliper.

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Tom Owen
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Re: Stop Surface Checks?

Post by Tom Owen »

The other trick is to weigh the wood when the weight stays the same for 2 or 3 months you may be good to go...

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