The Forestry Forum

General Forestry => Drying and Processing => Topic started by: kelLOGg on July 18, 2018, 01:35:31 PM

Title: Sterilizing barn wood
Post by: kelLOGg on July 18, 2018, 01:35:31 PM


I have a customer who built a piece of furniture out of barn wood and now bugs are emerging from it into the house. To prevent this from happening again on another upcoming project he has asked me if I could dry/sterilize about 40 bd ft of 2" thick pine barn wood.

My kiln has a domestic DH unit in it and I don't operate it above the 90s to prolong its life. I doubt his wood would need drying - only sterilizing and I am considering that because it would not require running the DH unit. I have electric heaters in the kiln and have gotten it up to 140 in the past. It is a terribly small amount of wood to put in a kiln; perhaps one could devise a makeshift drying/sterilizing technique for this specific purpose. Could anyone comment on this? I would like to help him out.
Bob
Title: Re: Sterilizing barn wood
Post by: SawyerTed on July 18, 2018, 04:36:18 PM
You should be able to devise a solar collector to reach 135 degrees without a a problem for a small amount of lumber.

My solar collector for heating water has no problem reaching and holding 140 degrees 
Title: Re: Sterilizing barn wood
Post by: Ga Mtn Man on July 18, 2018, 05:52:40 PM
Attics get awfully hot around here.
Title: Re: Sterilizing barn wood
Post by: btulloh on July 18, 2018, 07:12:05 PM
I agree with Sawyer Ted.  It's sound like it's a small amount of lumber.  If you scrounge up some kind of glazing, all you need is an insulated box or structure just big enough and painted black on the inside. You will need something to circulate the air.
Title: Re: Sterilizing barn wood
Post by: YellowHammer on July 18, 2018, 10:50:58 PM
Id wait until your next load in the kiln need sterilization, then piggy back this mini load on top of yours.  I do this for some of my customers and works fine.  Normally, I piggyback the load when the current load is a couple percent above ideal MC, so I can physically insert it on top of my current kiln load, bring the MC down a couple percent to synchronize it with my load, and go right to sterilization.  
Title: Re: Sterilizing barn wood
Post by: GeneWengert-WoodDoc on July 19, 2018, 02:13:04 AM
For a one-shot deal, rent a trailer and use an electric heater that will run up to about 150F.

To sterilize, we need 133F within the lumber.  Most solar kiln come close in the hot summer, but are not perfect.  For frequent sterilization, including pallets, build an insulated room with insulation that can withstand 150 F.  Use smoke alarms and other safety features.  Keep it away from home and shop.
Title: Re: Sterilizing barn wood
Post by: Brad_bb on July 19, 2018, 12:08:10 PM
With dry barnwood, really the only bug you're going to get is Power post beetles/larvae.  Their cycle is pretty slow.  Once there is a finish on the wood, the mature beetles will no longer lay their eggs in the wood.  What they are probably seeing is the emergence of ones that were there before finishing.  Once those hatch out, you probably won't see any more.  This is what I learned from my research.

I've been using a lot of barnwood for trim etc lately, mostly oak, but some beech and a little maple.  My favorite finish is General Finishes High performance flat, 2 coats.  It's a flat urethane that makes the barnwood look good without making it look "plastic-y".  

If there is some other bug, let us know and post some pics.  You probably wouldn't need to but you could also go the chemical route using a borate.  You just have to know what you're doing so it doesn't affect the finish you want to apply.  With kiln sterilization, there is some risk of warpage.  Not sure how much?
Title: Re: Sterilizing barn wood
Post by: DR_Buck on July 19, 2018, 01:50:55 PM
I sterilize every load of lumber I dry in my DH kiln.    The last 24 hours after I reach target MC,  I run the temp up to 160.   Haven't had any issues in over 10 years now.
Title: Re: Sterilizing barn wood
Post by: kelLOGg on July 29, 2018, 07:58:50 AM
My customer brought the barn wood yesterday. I drilled a 1/4" hole in the end of a test piece and inserted a thermocouple. The TC is encapsulated with epoxy in a 1/4" plastic tube and made a very tight fit in the hole. I inserted it 2" in the 2" lumber. Turned on the heaters, set the thermostat at 140F and 6 hrs later the air temp was 130 and the inserted TC read 124. Went to bed and I was not awakened by any fire trucks during the night.;D Left it for 9 hrs and the air temp and inserted TC reading was 138F. I assume it was at 133F long enough to do the job. I turned off the heat and am now letting it cool slowly in the kiln. Comments?
Title: Re: Sterilizing barn wood
Post by: kelLOGg on February 19, 2019, 06:04:24 AM
SouthSide's thread on sterilizing reminded me that I never followed up on my thread. 

When I opened the kiln the counter top was still flat - glad it didn't warp! There were dead carpenter bees on the floor, so I assumed I assumed the process was a success. Customer was please with the results and so was his customer.