kiln dried Walnut

[Cazzhrdwd]

I finished drying some Walnut yesterday, all seem to go well. I mixed some green with air dried, both came down to 8 % but the air dried boards were much heavier than the green ones. I had to put the meter back on them more than once just to make sure I wasn't missing something.

Has anyone experienced AD walnut being heavier than Walnut dried from green?

[Glenn1]

That does seem to be strange.  I have a __ pin meter but I don't put too much faith in it.  I weigh my samples and then try the test samples in the microwave.  That method seems to be the most accurate.

Have you cut a cross section of the walnut and used your meter in the middle of the boards?

Are you familiar with the method of weighing the wood based on dried samples and the actual sample in the kiln?.  If not, there are many members here that can help.

[beenthere]

I finished drying some Walnut yesterday, all seem to go well. I mixed some green with air dried, both came down to 8 % but the air dried boards were much heavier than the green ones. I had to put the meter back on them more than once just to make sure I wasn't missing something.

Has anyone experienced AD walnut being heavier than Walnut dried from green?

How did you determine that the air dried boards were much heavier than the green ones?  and how much heavier were they?

[Cazzhrdwd]

Have you cut a cross section of the walnut and used your meter in the middle of the boards?

No, the meter reads the same on several different boards.

[Cazzhrdwd]

How did you determine that the air dried boards were much heavier than the green ones? 

Only by handling them

and how much heavier were they?

Not sure, almost twice as much, but can't say for certain.

[YellowHammer]

My guess is that the wood still has a wet core, walnut is prone to trap core moisture, even if the outer case reads dry.  I've had it happen to me.  As Glenn1 says, oven dry technique is the definitive answer.

[Seaman]

I would say the air dried boards are much drier. Water is about the only thing gonna make the others heavy. Cut cross sections and check again. The meter is not reading deep enough into the wood to be accurate.
FRank

[Cazzhrdwd]

That would be my guess, but the air dried ones are the heavier ones. I use the Delmhorst j2000 with the slide hammer, it has the 1 1/2 pins on it and usually gets decent readings on the core. But I agree the core has to be the culprit. It seems to be about five 9' boards that are 12 inches wide that are the heavier ones. 45 bdf out of 400 that seems to be different.

YH I'm used to Walnut being difficult, this load was at 160° for 3 days and I do believe these heavier boards have moisture in them still.

[bkaimwood]

I've run into the same...air dried, in the kiln FOREVER, still showing high core MC...not much more I can do, except keep waiting...it ties up another full load...time to sell it advising the buyer accordingly, needs time yet...move it,  discount it, and move on...keep + cash flow

[GeneWengert-WoodDoc]

You have the perfect meter for checking MC.  The density of wood changes about 10% due to shrinkage, when drying, but there is no difference between air dry-kiln dry and straight kiln drying.  So, if there is a difference, it is due to growth difference, not drying.