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thinking of building a drying box

Started by yukon cornelius, December 13, 2015, 09:20:12 AM

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yukon cornelius

I am wanting to build a box for drying some wood but mainly for killing any sort of bug that could possibly be in the wood. my thoughts are 4'x4'x9'.  I think I would like it to reach 150-170 degrees. I have a heating element, fan, timer, and safety's from a electric dryer. the timer goes to 90 minutes I believe. the temp control is set for 150 degrees. from what I have read, we need the wood to "bake" at 150 for 6o to 90 minutes. so in theory, these controls should fit the bill perfectly. I also have some thoughts for a duct port for a wood or gas furnace to blow in. i have a background in hvac, and electrical and believe i have the fire hazard portion addressed in the design.

I would like to be able to bake our cedar logs for our log furniture. we use 1-6" logs generally. the larger the log, the more cook time?

any advice for the temp and time or any other suggestions?
It seems I am a coarse thread bolt in a world of fine threaded nuts!

Making a living with a manual mill can be done!

GeneWengert-WoodDoc

The rule for sanitizing lumber or any wood product is the entire piece, inside and out, must reach 133 F.  This can take much longer than 90 minutes at 150 F.  For a log pie.ce, it could take 24 hours or so.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

yukon cornelius

Thanks! maybe a test or several. Bake for a set time and immediately cut it open and temp test. The average size I plan on is 2-4 inch range.
It seems I am a coarse thread bolt in a world of fine threaded nuts!

Making a living with a manual mill can be done!

Ljohnsaw

Quote from: yukon cornelius on December 13, 2015, 09:20:12 AM

I would like to be able to bake our cedar logs for our log furniture. we use 1-6" logs generally. the larger the log, the more cook time?


Other than big black carpenter ants in the rotted heart, I've never seen anything IN cedar.  Just bark grubs eating the cambium layer.  Do you leave the bark on?  I wouldn't think you need to heat treat it.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

yukon cornelius

We always peel the bark. We have only foundd grubs but would like to add an extra step of heat treating to make sure. Besides that, sometimes we end up with greener logs than we would like and a place to dry them a bit faster would be nice.
It seems I am a coarse thread bolt in a world of fine threaded nuts!

Making a living with a manual mill can be done!

GeneWengert-WoodDoc

I assume you are talking about western red cedar...true?  Note that there many many cedars, but almost all are a different genus..white cedar is the only close relative in North America (genus is Thuja).  So, drying of WRC is quite a bit different than most other cedars including Alaska yellow, eastern red or aromatic cedar. 

Be very alert for large logs, as the MC of the lumber can be extremely high...so high that the logs will not float in water.  Such lumber must be dried very slowly.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

beenthere

Looking at yukon's gallery and posts, I suspect it is ERC.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

yukon cornelius

Sorry, yes eastern red cedar. I should have posted that but forgot.
It seems I am a coarse thread bolt in a world of fine threaded nuts!

Making a living with a manual mill can be done!

21incher

I plan on building one soon also. I only use short pieces and have very little room left in my shop so I am looking for one of those old steel office cabinets that is 36" x 18" x 6 ft high with removable shelfs on craigs list to use for the box. I plan on lining it with insulation and just using one of the low cost STC-1000 temp controllers with a relay to control the heater, and a fan in the box to keep the temp even. The only thing that I am wondering about is should I keep it sealed to keep the moisture in and hopefully not add stress to the lumber, or should it be vented which could remove moisure from the surfaces and cause stress. :)
Hudson HFE-21 on a custom trailer, Deere 4100, Kubota BX 2360, Echo CS590 & CS310, home built wood splitter, home built log arch, a logrite cant hook and a bread machine. And a Kubota Sidekick with a Defective Subaru motor.

yukon cornelius

To vent or not runs through my mind also. I believe I will add a sliding vent to adjust for humidity and some for slow cooling so not to shock the wood. I think I may build mine horizontal and a workbench top on it. Multipurpose.
It seems I am a coarse thread bolt in a world of fine threaded nuts!

Making a living with a manual mill can be done!

GeneWengert-WoodDoc

Vented is critical, as when the moisture leaves the lumber, you need to get it out of the dryer.  With oak, for example, each 1% MC loss is about 4 gallons of water from 1000 BF of lumber.  Of course, if you vent too much, then all the heat goes out.  So, the vents should be controlled to open when the humidity is too high and close when the RH is too low.  The key is to achieve the correct humidity, which is given in a kiln schedule (widely published).

The moisture is very acidic, so it will rust the steel components in no time at all.

Heaters can be hard to find as you want to go to 150 F or hotter, and do it safely...the contents are combustable.

Note that stress only develops at very high MCs, so if you air dry first, you will not be able to make any more stress.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

yukon cornelius

Thank you! That is just the kind of info I was looking for. i think I will procede with this project soon. I hope to get some pics as I go.
It seems I am a coarse thread bolt in a world of fine threaded nuts!

Making a living with a manual mill can be done!

21incher

Thanks for the info. Sounds like using a steel cabinet may not be a good idea. I thought using steel and lining it with fire rated  insulated drop ceiling panels would offer some fire protection and be real easy to make. I am wondering how much drying will actually happen in a single heating cycle to eliminate borer problems. :) 
Hudson HFE-21 on a custom trailer, Deere 4100, Kubota BX 2360, Echo CS590 & CS310, home built wood splitter, home built log arch, a logrite cant hook and a bread machine. And a Kubota Sidekick with a Defective Subaru motor.

GeneWengert-WoodDoc

When drying ERC, we find that we have the best aroma after drying if the drying process did not go over 80 F.  When you go hotter, the dry kiln and local environment smells awesome, but the aroma is being evaporated from the lumber.  Many people dry ERC using a warm room, rather than a kiln such as used for hardwood drying.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

yukon cornelius

Quote from: GeneWengert-WoodDoc on December 17, 2015, 08:21:38 AM
When drying ERC, we find that we have the best aroma after drying if the drying process did not go over 80 F.  When you go hotter, the dry kiln and local environment smells awesome, but the aroma is being evaporated from the lumber.  Many people dry ERC using a warm room, rather than a kiln such as used for hardwood drying.

Thank you for that info. I appreciate your help!
It seems I am a coarse thread bolt in a world of fine threaded nuts!

Making a living with a manual mill can be done!

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