Drying Already Dry Lumber

[DR Buck]

Had a customer bring a load of recovered barn siding and some 4x4, 4x6 and one 8x8 beam he wanted run thought the kiln to "kill bugs".    Some of the stuff had evidence of powder post beetles on it.   The species was mixed and I really couldn't identify much of it.  There was some oak, poplar, pine and some he said was chestnut.   All of it measured ~9% MC.  The 4 by and larger stuff had some checks and splits at various places.

I stickered it in the kiln and and set the DH4000 control to 160º and RH at 60%.  I'll never get enough moisture to reach 60% but since I'm only trying to kill bugs I'm not concerned with RH in the kiln.   My plan is to run it at 160º for 3 days or so.

Questions are:   1-  Will 3 days be long enough to kill off everything?   2-  I don't think running at 160º right off the bat with such a low mc in the wood is going to hurt, but I'm looking for confirmation from others.

[GeneWengert-WoodDoc]

160 will kill everything indeed.

Going to 160 immediately is fine.

Try putting some (maybe 10) trays of water in the unit to increase the humidity.  Otherwise, keep it sealed tightly.

[scsmith42]

I do this type of drying all the time, in my instance I will run it at 120 for the first two days and then 160 for the third (to set the pitch in the pine at the same time as sterilizing).

Even a few hours at 160 will sterilize 4/4 lumber.

[xlogger]

When you have people bring you lumber to kiln dry at your place and the lumber has bugs like the powder post beetles in it, does it spread at your place? Also will a solar kiln get hot enough to kill them?

[WDH]

Would 145 degrees for 24 hours be enough to sterilize?

[scsmith42]

Would 145 degrees for 24 hours be enough to sterilize?

Probably, although the 8 x 8's might be questionable if the core would be higher than 130 after 24 hours.

Since some of the load is pine, max temp is best to set the pitch.

[GeneWengert-WoodDoc]

Current guidelines are that the interior of the wood must be 133 F.  If the air temperature is only 145 F, it will take a long time...maybe 24 hours...for the core to reach 133 F.

[sawwood]

We have a solar kiln and can you use it to redry wet wood. We hade a stack of lumber
that we dried and covered but the tarp leaked and the lumber is wet. Most of the wood
is cotton wood and some red oak. It is going to be used for siding so it doesn't need to
be real dry.

Sawwood 

[WDH]

My question of 145 degrees for 24 hours was for 4/4 lumber.