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cypress slab

Started by sumrallmike, February 22, 2014, 10:46:37 PM

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sumrallmike

We have a rough cut  6 1/2 ft  x 4 ft x 4 in slab of cypress.  We think it is sinker cypress, but it may not be (we're going to call and confirm later).  We want to finish as the top of a kitchen island.  We have recently read that it takes a year of drying for every inch of thickness.  This is a bit longer than we want to wait.  We have been told that we could finish it on the top and leave the bottom unfinished and it will dry out and be okay, but are not sure that is correct.  If we bring it inside our house, would the lower humidity conditions speed up drying?   Anyway expertise and advice are greatly appreciated. Thank you. 

GeneWengert-WoodDoc

I do not know the origin of 1" per year, but that is not correct.  It is often applied to air drying, but is not correct.  For example, soft maple and pine will air dry very well in 45 days of good weather.  Oftentimes oak is done air drying in 90 days.  Cypress, like you have , must be dried slowly, especially the first month or two, but after 90 days should be quite low in MC...depending on the weather.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Ianab

Suggest you get a moisture meter, then you KNOW what's going on.

Cypress will dry MUCH faster than a year per inch, that's a real worst case scenario, and bringing it into a warm dry environment will speed that up, especially if you use fans for extra airflow. You may need to be more careful with old sinker cypress, not to dry it too fast, but even then, I doubt air drying with fans will damage it.

Finishing one side would be risky. What happens then is that one side dries faster then the other, and so shrinks. Shrink one side more than the other, and the whole slab cups. It may eventually even out, but in the meantime you have a warped top.

Possible suggestion would be to mount it in place, not totally dry, and just finish it with a light oil/wax, like you would use on a cutting board. Make it easy to remove. Then once it is fully dry, take it out, resurface it to correct any warping, and apply your final finish?

BUt checking that moisture level is the first step.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Seaman

I agree with Ian. We have several customers who have installed one piece ( no glueup ) slabs in their house. It helps to use elongated slots for the fasteners holding it down to allow a little movement, don't tighten, just snug up. Take it uot later to finish.
Frank 
Lucas dedicated slabber
Woodmizer LT40HD
John Deere 5310 W/ FEL
Semper Fi

MattJ

I can say I tried this technique once before with a cherry slab clock and it turned out poorly.  The moisture was trapped and you could see it as blotches below the finish.  The slab then warped and crushed the clock mechanics.  I ended up drilling holes in the back to help the moisture escape but it caused a lot of checking.  Not a great idea.

Ianab

Hence the advice to not finish it until dry, and mount it loosely so it can move. Green wood WILL shrink as it dries, sometimes unevenly (which makes it warp). There isn't a lot you can do to stop this, you basically have to let it happen, then clean up the end result. Fortunately cypress is a lot more stable than cherry which makes life easier.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Den Socling

I have some experience with 8/4 Sinker Cypress. The logs were recovered from a river bottom and I was told they were more than 100 years old. I thought it was going to be easy in my vacuum kilns. It was not. They wanted MC at 11%. I would have the majority of the boards around 11% but would have very small, very high wet pockets. I even had some surface checks. It was not easy and I expect that you could have a hard time with a 4" slab if it truly is Sinker Cypress.

GeneWengert-WoodDoc

Sinker cypress is not normal.  Rather it results because there are bacteria in the tree.  They are in the butt log,coming into the tree through the roots.  Somehow, they increase the MC so high that the log will no longer float.  But the big issue is that the bacteria, that live in no air conditions (anaerobic), create an enzyme (enzymes are a protein molecule so the enzyme is not alive) that weakens the wood.  Hence infected wood, including fresh wood today, or 100 year old cypress or any infected species, will dry with wet pockets and with checking.  Wet pockets are fixed by waiting.  Checking is prevented by very slow drying.

Probably 100% of logs on the bottom of lakes! rivers! and creeks did not float, but sank, due to bacterial infections.  Be careful with this material.

The thicker the material, the greater the drying problems..wet pockets and checking...but we can even see it with 4/4 at times.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

mesquite buckeye

Manage 80 acre tree farm in central Missouri and Mesquite timber and about a gozillion saguaros in Arizona.

sumrallmike

Thanks for the information.

thecfarm

sumrallmike,welcome to the forum. Did you buy this slab? Or did you saw it?
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

dchiapin

I saw quit a bit of sinker cypress here and I agree with gene that it does dry very slowly because of the wet pockets that have formed. My suggestion is to air dry with plenty of air flow (of course out of any weather or direct sunlight) for at least a year before bringing into your house.
Do not seal with any poly or resin until you are quit satisfied the wood is completely dry, other wise you will have little white pockets of moisture form under the sealer and these are not pretty. The sealer on one side also allows for uneven drying and sometimes will allow the table top to bow slightly.
This wood is very soft, unlike normal bald cypress, so it dents very easily.
Sure is beautiful wood and well worth the effort to protect it.

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