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Freshly sawn pine at 16.5% MC?

Started by kelLOGg, January 13, 2016, 09:07:51 PM

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kelLOGg

A customer brought me some rather ugly logs with opposing sweep in the same log and many knots. It was about 16" at the butt and with very dense rings - ranging from 20 and higher per inch. (I will need a magnifying glass to see them clearer.) They sawed beautifully and made straight stress-free lumber 4 to 10" wide (but with a lot of waste), all 3/4" thick, at their request. If that wasn't surprising enough, the moisture content was. A day after sawing I stickered them under shelter and inserted the moisture probe. I was expecting no reading at all because surely the MC was out of range but, no, it read 16.5%. We have finally had some dry air days but I wouldn't expect drying to occur so fast. What gives? There was very little blue stain and in very few boards so the tree had not been felled for long.

Bob
Cook's MP-32, 20HP, 20' (modified w/ power feed, up/down, loader/turner)
DH kiln, CatClaw setter and sharpener, tandem trailer, log arch, tractor, thumb tacks

GeneWengert-WoodDoc

A couple of possibilities...
1.  It actually is 16.5% MC, having dried on the stump before felling.
2.  The meter is correct because the wood is hear pine, which has low MCs in the tree.
3.  The meter is right because such wood has dried, at least the surface.
4.  The meter is wrong because it is not working right.
5.  The meter is wrong because the high resin content stops good electrical contact.
6.  The meter is wrong because the unusual growth requires a different calibration, but this would not be large.

Or a combination of several.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

kelLOGg

Thanks for the reply, Gene.

I have a few more observations:
1) the meter probes are inserted to about the midpoint of the boards,
2) the reading fluctuates wildly (~12% to 19%) and seems to be higher in the early AM and after dark when the RH is highest,
3) with the probes inserted in dry oak the reading is stable (~6.9%)
:P

Bob
Cook's MP-32, 20HP, 20' (modified w/ power feed, up/down, loader/turner)
DH kiln, CatClaw setter and sharpener, tandem trailer, log arch, tractor, thumb tacks

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