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(10-21-2022, 04:05 PM)jteneyck Wrote: That would be a really, really bad idea, especially if the RH is low. It will crack for sure if you dry it too quickly, too soon. You need an RH of about 90% in the beginning drying stages for 2" thick red oak. If you must put it in the garage then just leave the windows and doors open as much as possible and run the window fan. Leave them open at night, too, if possible, so the RH can rise again so the wood will relax. This is what happens outdoors and in solar kilns. If you want to speed up the process with a heater and fan inside a plastic enclosure you need to do it properly by weighing test specimens and controlling the temperature and RH. By guess by gosh is likely to lead to major disappointment.
Outside is the easiest offers the best chance of minimizing degrade of nearly any alternative short of kiln drying.
John
Maybe I'm misunderstanding kilning but it seemed to me like the DIY kilns I've seen online were an insulated box, a dehumidifier, a fan, and a heat source. My thought was that plastic sheeting would have no real R value, just provide a way to direct the warm air. It sounds like drying in a kiln would be much faster than that - again, unless I'm misunderstanding, there isn't that much control over the rate at which drying occurs in a kiln. I'm guessing based on what you're saying this is wrong.
I do have space outside that I can utilize. Sounds like a plain old dry stack (it will be relatively shaded in the summer, preventing excessive drying from the relatively brutal summer sun) will work. I do need to level it a bit, at least unless I want to use the driveway (leaning towards no). I think I can level an area with cinder blocks and bricks so I can just stack it out there. Not like grass grows there anyway.
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(10-20-2022, 08:55 AM)FS7 Wrote: This had occurred to me (not a common species for slabs), but I was thinking I would end up with 30-40 (or more) 2" slabs. This is a "premium" market for woodworking stuff, so it wouldn't take much. I mean people sell red oak on Craigslist for $5 a board foot rough (or at least they have it listed for that). Selling a 30 board foot live edge slab for $100 is probably doable given what the market here seems to be.
Worst case, I end up with way more bar top material than I wanted.
yes, people will buy red oak slabs if it's only about 100.. that's a great deal if the slab is 2" or more and doesn't warp.
I bought 2 slabs from someone to make a maloof style rocker from.. not red oak, but it could be.
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(10-21-2022, 08:17 PM)FS7 Wrote: Maybe I'm misunderstanding kilning but it seemed to me like the DIY kilns I've seen online were an insulated box, a dehumidifier, a fan, and a heat source. My thought was that plastic sheeting would have no real R value, just provide a way to direct the warm air. It sounds like drying in a kiln would be much faster than that - again, unless I'm misunderstanding, there isn't that much control over the rate at which drying occurs in a kiln. I'm guessing based on what you're saying this is wrong.
I do have space outside that I can utilize. Sounds like a plain old dry stack (it will be relatively shaded in the summer, preventing excessive drying from the relatively brutal summer sun) will work. I do need to level it a bit, at least unless I want to use the driveway (leaning towards no). I think I can level an area with cinder blocks and bricks so I can just stack it out there. Not like grass grows there anyway.
I am not an expert, but typically I think it's best practice to air dry to around 15% moisture like John said.
Then you kiln it. John really knows his stuff, I would follow his advice.. (I'm not trying to be a jerk, I just admire his knowledge.)
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(10-21-2022, 11:20 PM)paul2004 Wrote: I am not an expert, but typically I think it's best practice to air dry to around 15% moisture like John said.
Then you kiln it. John really knows his stuff, I would follow his advice.. (I'm not trying to be a jerk, I just admire his knowledge.)
I know he knows his stuff. That's why I'm listening (and learning). I think the current plan is to air dry outside down to whatever I can (I have no idea, as I've never done it) and then maybe build a small kiln inside for a few slabs or boards at a time. Maybe not even use the garage at all.
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10-22-2022, 08:59 AM
(This post was last modified: 10-22-2022, 09:08 AM by kurt18947.)
Air dry outside then bring it inside to finish. A kiln is nice but for a one off load, air drying has worked for many centuries, it just takes longer. If it were me I'd invest in a moisture meter. I did and use it fairly often. A business is going to want kiln dried at least in part because they don't want to monkey around checking moisture, they want a uniform product that they can bring wood in one door, process it and get it out the other door as fast as practical. Kiln drying also reduces the chance of bugs but you could take steps to reduce the likelihood of any bug infestations. It's not like you'd be dealing with 10s of thousands of board feet and you know the history of the wood. It hasn't laid on the ground for weeks or months waiting for bugs to take up residence.
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10-22-2022, 09:23 AM
(This post was last modified: 10-22-2022, 09:25 AM by Cabinet Monkey.)
(10-21-2022, 03:56 PM)jteneyc Wrote: Where I am in NY slabs sell MUCH easier than dimensional lumber, regardless of species. Of course, walnut is easier to sell than red oak, but I've sold quite a few red oak slabs for more $/bf than what I can get for dimensional red oak lumber. There are a lot more fixer upper folks than woodworkers.
Walnut sells itself pretty much everywhere.
Round me, red oak is firewood. For this one, I suppose it only matters what the folks of Northern VA think.
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(10-21-2022, 08:17 PM)FS7 Wrote: Maybe I'm misunderstanding kilning but it seemed to me like the DIY kilns I've seen online were an insulated box, a dehumidifier, a fan, and a heat source. My thought was that plastic sheeting would have no real R value, just provide a way to direct the warm air. It sounds like drying in a kiln would be much faster than that - again, unless I'm misunderstanding, there isn't that much control over the rate at which drying occurs in a kiln. I'm guessing based on what you're saying this is wrong.
I do have space outside that I can utilize. Sounds like a plain old dry stack (it will be relatively shaded in the summer, preventing excessive drying from the relatively brutal summer sun) will work. I do need to level it a bit, at least unless I want to use the driveway (leaning towards no). I think I can level an area with cinder blocks and bricks so I can just stack it out there. Not like grass grows there anyway.
They often are, but you still have to operate them much like a commercial kiln by controlling the RH and temperature to avoid degrading the lumber. Take some time to learn about kiln drying. There is lots of info. at the Forest Products Laboratory. It's not rocket science, but it takes some effort to weigh samples and adjust the kiln to stay within the drying limits, especially during the first 1/3 of the process. Air drying is subject to its own set of problems, but most can be avoided by setting up the racks in a spot with little direct sun exposure. Bug infestation is probably the biggest concern, doubly so with live edge material. Keep those separate if possible, or spray everything with Timbor or something.
The equilibrium moisture content depends upon the RH of your area. Where I live in the NE air dried lumber will get down to 12 - 14% moisture content, at which time you can bring it indoors to let it dry the rest of the way which, again for my area, should be 6 - 8% moisture before using it for indoor projects. Drying indoors can be as simple as drying outdoors. Just rack it up in a conditioned space and leave until it dries. if you do it that way, don't try to help it along by blowing warm air through the stack. It's hard to ruin air dried wood, but no impossible. Or now you could build that simple dehumidification kiln to speed up the process but, again, you need to stay below the maximum allowable drying rate for the species and thickness you have. It's all in the FPL info. I follow EBAC's drying schedules with my kiln.
John
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The thing with a commercial kiln is that it controls the temperature / humidity and airflow to get the best possible Safe drying rate. And this depends on species and thickness of the wood. This is hard in a DIY kiln, but once wood is "air dry", down around 15%, it's hard to mess up. So a DIY box with a DH, a couple of light bulbs and a fan will complete the drying just fine. In a commercial drying operation there is pressure to get the product dry and moved on, and get paid for it. Can't wait 6 months for air drying then another 2 weeks in a Heath Robinson kiln. They want the wood into the kiln, the drying conditions cranked up to the max safe rate, and have the wood ready to go in a couple of weeks. (or a couple of days for easy to dry pine). At home you aren't in so much of a rush, and going into Winter you will have slower (safer) air drying. By they time Summer arrives the air drying will be well advanced and less risk.
Bugs can also be an issue with some woods. A commercial kiln will heat the wood up to ~140F+ at some point, Any larvae or eggs that happen to have sneaked in get cooked above that temp. A surface treatment of borate will discourage them from moving it too. (John's Timbor suggestion). I have treated some of mine by dipping it in a trough of borax solution, seems to have worked. Some species are less palatable to bugs, so I don't treat cedars / cypress etc.
Building a drying stack yesterday, excuse the sloppy alignment of the sticks, I'm trying to shake a head cold, but had to get these off the flat stack on the trailer, and my head wasn't really in it yesterday. But it's Monterey cypress, mostly 2" thick, and will dry OK in a less than perfect stack.
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Well, we milled it today. Total yield was about 2000 board feet, roughly half being 8/4 full slabs and half being 5/4 quartersawn boards. Not bad for $.40 a board foot.
On the downside, my driveway looks like a lumber yard.
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(11-09-2022, 07:29 PM)FS7 Wrote: Well, we milled it today. Total yield was about 2000 board feet, roughly half being 8/4 full slabs and half being 5/4 quartersawn boards. Not bad for $.40 a board foot.
On the downside, my driveway looks like a lumber yard.
The miller must have had a pretty nice mill. I think my max. production was just over 1000 bf in a day with my completely manual bandsaw mill.
How are going to move those full width 8/4 slabs?
John
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