Lower than expected moisture reading

[Dan McGonigle]

Hey guys, this morning I checked moisture on a few cherry slabs I cut 6 months ago. I was surprised when my meter read 13%. A few things to note - I use an inexpensive pin meter, and these slabs were not sealed on the ends. I cut 4 8/4 slabs from this log and was lazy, so I didn't seal them. I had expected splits through the pith in 1 or 2 anyway. Also, this log was down for a year or two before I milled it. I thought it would be higher than that considering the old 1 year per inch rule. 12% is the average reading in my stacks of walnut that have been drying for 4-5 years now. So why so low? Is this an example of case hardening? Just for fun I checked moisture of whatever kiln dried stuff I had in my shop, which was what I expected - 8%-10.5%, so I'm pretty sure my meter is reading somewhat accurately. Any air-driers out there than can give their thoughts? Thanks

[Tom Hogard]

Dan, I don't think that a 13% reading would be unusual after 6 months, considering that your pin meter is reading the surface moisture content. The actual EMC of your 8/4 slabs is probably quite a bit higher, it will take some time for the core moisture to wick its way to the surface. Absent purchasing a pin meter with longer probes (3/4" deep), or a pinless meter with deep reading capability (both expensive options), you could sacrifice one of your planks and do an oven drying test (very accurate, low cost unless your wife catches you), or you could simply track the weight of the same slab every month or so and wait for the weights to level off, at which point it would be in equilibrium with the surroundings.

[Dan McGonigle]

Thanks, that's a good idea - weighing it periodically. I can tell just by lifting the top slab that its not dry. I'll probably end up waiting a few years before using them anyway. I would love a nice pinless meter, but it's not in the budget!

[Scott T Smith]

Hey guys, this morning I checked moisture on a few cherry slabs I cut 6 months ago. I was surprised when my meter read 13%. A few things to note - I use an inexpensive pin meter, and these slabs were not sealed on the ends. I cut 4 8/4 slabs from this log and was lazy, so I didn't seal them. I had expected splits through the pith in 1 or 2 anyway. Also, this log was down for a year or two before I milled it. I thought it would be higher than that considering the old 1 year per inch rule. 12% is the average reading in my stacks of walnut that have been drying for 4-5 years now. So why so low? Is this an example of case hardening? Just for fun I checked moisture of whatever kiln dried stuff I had in my shop, which was what I expected - 8%-10.5%, so I'm pretty sure my meter is reading somewhat accurately. Any air-driers out there than can give their thoughts? Thanks

The “one year per inch” rule is an old wives tale. About the only domestic species that this applies to is oak.

In the southern US in the summer, 1” pine will fully air dry in 2 months. Same with 1” poplar. Walnut and maple around 4 -5 months. Your cherry could certainly have air dried down to 13% in 6 months.