I have a bunch of Claro Walnut slabs a client provided that are 2 1/2″ – 2 3/4″ thick. They were dried outside for 4 years and before I accepted them the slabs were reading about 10-11%. My other slabs in my shop seem happy at 8-10% (I am in San Francisco, these slabs will be going inside in a climate controlled environment, almost identical to my shop).
I did my initial flattening and planing (planning on step milling them) and as I finished my first passes I went to check the moisture again, suddenly I am getting readings more in the 12%-17% range, with some very small pockets reaching 20% (I know moisture pockets are common in Claro). Theyve been sitting for about 2 weeks now on saw horses with very little movement, no new checking, and none of the existing checks getting any bigger.
I know the best thing to do here is to stop and put them in a kiln, however due to timeline and budget, this really is not an option. These slabs are also all being used as free standing bar tops (sitting on brackets), so movement isn’t as big of a deal as it would be if these were being put on wooden legs or something similar.
Looking for some advise, I can afford to stack it with air movement and maybe a dehumidifier for a couple weeks, maybe build a light bulb kiln, or maybe just continue if a couple moisture % aren’t as big of a deal as I think they are.
Thanks
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I live in the SF Bay Area as well (Livermore to be precise). In my shop (errr, really a garage), the moisture in my wood settles to low teens in moisture content. I have also lived significant durations in both Daly City and San Francisco. It is slightly more humid there than Livermore. At 12-17%, I'd say the wood is at harmony with its local environment and I'd move forward. The 20% moisture pockets would make me a bit nervous (I have some eight quarter oak with the same issue as yours) and if I had time, I'd likely way a little longer to see if it settles down. If not, I'd proceed without any real fear. In the Bay Area, it's likely at or very near the moisture it will normally be at.
Wow thanks Joe! Great to get some local insight, appreciate it.
Some meters can read further down in a slab than others. Yours may be reading the surface, rather than the middle. That may be why planing a little makes the numbers jump.
A few more weeks for a 2-3/4" slab won't make a difference, just sitting in your shop. A real kiln would. Your end result will depend in part on where in the tree the slab comes from. The more quartersawn it is, the flatter it will stay. The closer to the outside of the tree, the more likely it is to cup.
Interesting. I should have stated in the original post I’m using a Wagner meter that reads 3/4” deep. I originally measured top and bottom, so just the bit I took off means it’s picking up moisture pretty deep.
3/4" measured in from both sides still leaves you with a 1" mystery center. This is a job for a long-pin meter. If you can afford to cut one in half or take a core with a plug cutter to see what's what deep inside it could tell you a lot.
Yeah I tried to borrow one. Typically I’m not in this situation with slabs and buy from a sawyer that specializes in claro, but a stipulation of this job was using these specific slabs the client purchased.