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General Forestry => Drying and Processing => Topic started by: abosely on July 30, 2015, 05:44:49 PM

Title: Temperature & Time to Kill critters & Eggs?
Post by: abosely on July 30, 2015, 05:44:49 PM
At what temperature and for how long should lumber be kilned to kill bugs, eggs & fungus? Not for drying purposes, but just for 'sterilizing'.

I'm guessing there may be some variables such as at X temp, X length of time and at Y temp, Y length of time?

Cheers, Allen   
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: WDH on July 30, 2015, 09:51:14 PM
Several hours at an internal wood temp of about 135°.  That is internal wood temp, not air temp.  I usually sterilize at 150 degrees air temp for 24 hours.  This should allow the wood to reach an internal temp of over 130 degrees for at least several hours. 
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: YellowHammer on July 30, 2015, 11:49:08 PM
When you get it right, and critters will be crispy and broiled to perfection.   8) 8)
(https://forestryforum.com/gallery/albums/userpics/21488/Bug_hole.JPG)
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: LeeB on July 31, 2015, 08:38:07 AM
What kind of sauce would you put on them?  musteat_1
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: mesquite buckeye on July 31, 2015, 11:50:20 AM
Something spicy. ;D 8) 8) 8)

Duh :snowball: :snowball: :snowball: :snowball: :snowball:
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: abosely on July 31, 2015, 03:22:46 PM
Thanks WDH, that should be esy enough. The bug killing cycle should be done at end of drying correct?

Franks Red Hot for me! Love the stuff. lol

Cheers. Allen
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: YellowHammer on July 31, 2015, 10:31:48 PM
Quote from: LeeB on July 31, 2015, 08:38:07 AM
What kind of sauce would you put on them?

I keep trying to think of something clever but it eludes me.  I mainly just smile and flick their little bug bodies into dust.  I hate bugs in my wood.

Yes, the sterilization cycle commences at the end of the drying cycle


Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: GeneWengert-WoodDoc on July 31, 2015, 11:21:10 PM
The legal requirement is that the temperature throughout the wood (often called the internal temperature) be 133F, but there is no requirement for time.

Note that to get that hot requires an air temperature of perhaps 150 F or hotter.

The treatment can be done at any time, but the treatment is only effective for that moment in time; that is, it does not carry over to later in the life of the wood.
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: abosely on July 31, 2015, 11:39:55 PM
Yes, I understand it's like taking an antibiotic, it will (may) kill the sickness now but you can get reinfected right after.

I just want to kill any critters, eggs & fungi that might be in the boards and then will take steps to prevent re 'infection'.

As the lumber is used in the building process it will be completely encapsulated in 4 coats of epoxy.
Plus a lot of the lumber that will only need to be cut to length will be coated in epoxy ahead of time.
That way as I build I'm not trying to put coats of epoxy on wood in the hulls. It's like a thin syrup. Much easier to apply laying on sawhorses! Lol

Lightly sand surface before gluing pieces for bond. Everything gets pre coated before going in hulls. When finished it gets 3 coats of varnish for UV protection.

Cheers, Allen
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: Kcwoodbutcher on August 01, 2015, 04:10:03 PM
While that temperature will kill bugs it's not going to kill fungal spores. It would take a much higher temperature, in the neighborhood of 220 to 230, to insure no regrowth of fungus. If the wood stays dry then the fungus won't grow anyway.
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: flatrock58 on August 14, 2015, 10:58:21 AM
I was wondering what kind of heater could be used in a solar kiln to get the temperature up to 150 degf?
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: YellowHammer on August 14, 2015, 04:17:38 PM
I've not done it in a solar kiln, but in a well insulated DH kiln with less than strong enough heat strips, I used a total of four 500 kW halogen work lights, $20 each, to generate plenty of heat to get to that temperature.  The work lights are waterproof so they don't corrode, and I assume about as safe a heat source as I could get, except a steam radiator or other type of heat exchanger. 

Lesson learned, do not use an electric space heater, the fan will relatively quickly corrode and stop working and the heater will die. 

I have heard that the naturally convective electric baseboard heaters will work, as they don't have any moving parts, only a heat strip, but I never tried one.
Title: Re: Temperature & Time to Kill critters & Eggs?
Post by: GeneWengert-WoodDoc on August 14, 2015, 11:00:43 PM
Will the various building materials and hardware withstand 150?