Nyle drying quality

[rerednaw]

What is you opinion about quality of 50mm white oak dryed in nyle DH kiln ? is a crack exist ? Maybe someone can send to me photos of oak before and after drying in you kiln ? Thanks.

[karl]

I think what you are asking has more to do with the method than the machine.

[Den Socling]

Karl, I believe you are correct. rerednaw has his nouns confused. But I've been looking for responses. I know a little about DH and a little about drying 8/4 WO. I wouldn't expect a good match but was wondering if anybody could do it in a reasonable amount of time with reasonable degrade.

[Don_Lewis]

You should dry 8/4 Oak (red or white) from dead green. If you air dry, make sure you do it in cool weather, never in the summer or warm weather.  If you get it into the kiln as soon as it is sawn, it will look exactly the same when dry and will have no checks. You should develop zero defects from drying.

[Den Socling]

Don,

How long should it take for red and white 8/4?

Den

[Don_Lewis]

In a kiln that reaches 160F, the drying time should be about 65 days. In a kiln that reached 120F, it should take about 75 days.

[Den Socling]

Don,

Is that for red oak or white oak? They dry much differently.

Den

[oakiemac]

Should you dry 4/4 red or white oak from dead green as well? I have been air drying first and have not had unreasonable degrade. Although this has been with an Ebac. I'm loading my Nyle for the first time today.

[Den Socling]

oakiemac,

The problem with drying green 4/4 oak in a DH or 'conventional' kiln is that the energy cost are too high because it takes too long (from what I've heard).

Den

[Don_Lewis]

While Red and White Oak do dry differently, green White Oak is normally dryer so the starting point is different and the drying times are about the same.

It is less important to dry 4/4 from dead green as you get less degrade from air drying 4/4. Most people do air dry 4/4 at least to some extent. But the appearance out of the kiln will be better and defects from drying will be greatly reduced. And the lumber can be sold months earlier.

What are the "drying costs" if you lose 10% of the value of the lumber while air drying and that is probably on the low side with 8/4 Oak. The drying cost of 8/4 will still be less than 10% of the selling price of the lumber in most cases.

People don't write a check for degrade losses or lost income like they do for the electric bill or gas bill so those values often don't get into the equation but they are real and should be considered.

[GaS]

I agree, degrade losses can be very signifigant, but are typically written off as inevitable when they are exactly the opposite if you are careful.  Also, like you said, the money that would be tied up in inventory is instead more quickly moved without the air drying time.

People don't write a check for degrade losses or lost income like they do for the electric bill or gas bill so those values often don't get into the equation but they are real and should be considered.

Very good points.