We get lots of people asking to see more on our container kiln, with the Nyle L200M, loading and unloading, etc. So, I put a video together this week.
If you want to see some of our other videos, go to our Youtube channel.
Hobby Hardwood Alabama - Kiln Drying Lumber with Nyle Kilns - YouTube (https://www.youtube.com/watch?v=mYScqp3Euuo&t=1s)
Nice video!! I was expecting a subliminal message in the form of a crunched beer can placed somewhere in there. :D
Quote from: Southside on April 20, 2020, 08:46:03 AMI was expecting a subliminal message in the form of a crunched beer can placed somewhere in there.
Nope. That's in mine! smiley_nananana
Enjoyed that , thanks for posting.
Officially, there were no kilns harmed or otherwise mistreated in the making of this video. Anyway, that's my story and I'm sticking to it.
That was a great informative video. Nice job👍
Great job on the video. Very informative and like the attention to detail. Noticed in the beginning you commented on the load having sensor wires. are these moisture sensor wires or temp monitors? Can you explain a bit more on how you monitor the internal moisture of the wood or if these are to monitor the core temp of the wood for the sterilization process?
Thanks for the compliments.
The probes in the wood are resistance measuring moisture probes. They go directly to the control unit and display the moisture values on the screen. There are also two temperature probes, but they only measure wet bulb and dry bulb air temperatures.
I have settled on a useful sterilization procedure where I bring the kiln up to 150F and hold it for 24 hours, then slowly let it vent down over another 24 hours to ambient. So it's a drawn out process, but really helps soften stress in the wood, I call it "wilting" the wood, like slowly heating vegetables and then slowly cooling them in a crock pot. It really makes the wood behave better, with significantly less internal stress and removes any moisture gradient. Since there is such long heat up and cool down process, the wood core temperature gets to 150F (it only has to reach 135F) and stays for a day, so I don't need to measure the actual core temperature. Of course, the proof of the pudding of a sterilization cycle is if it actually works, and this one does. I always look for dead bugs (they look like black pepper) on top of the wood, and I don't think I've ever sterilized a live edge slab load where I didn't find crispy bugs. So it's very important to go overboard on sterilization, plus it also helps the characteristics of the wood.
Robert,
Enjoyed video. I'm finishing up my kiln and wondered what kind of fabric u used on your overhead baffle.
I've tried a few different things, but I keep going back to heavy canvas tarps available from Tractor Supply. The canvas is heavy so it doesn't blow in the wind, but it will degrade over time, and either rip to the correct height of the wood stacks, or just be replaced. The don't have to be very long, just enough to drape to the top of the stacks and and heavy enough not get blown by the fans.
Since I load my kiln with as much wood as possible, and bring each pile to almost touching the bottom of the fan deck, it takes minimal material to span that few inches and make a good seal.
I just let them hang like shower curtains and push the load in under them and pull it out without ever rolling or unrolling them. Some people use plywood and pulleys, but that's just one more thing I didn't want to mess with.
Excellant video, thanks
If you were to have time I would like to see a video of your Solar Kiln, I watched all of your videos and enjoyed them.
Thanks, I plan on eventually doing one one most of the phases of the operation.
I sometimes give lectures at the local woodworking shops, clubs and stuff, and we sure do get lots of questions about our kilns.
I am thankful for the information that you have shared, some of it I wish I had read earlier. Still is a steep learning curve on the solar kiln at my age most every new thing is a steep learning curve
One picture is worth a thousand words, so your video is worth many thousands.
One hint (to people building a kiln) about the top baffle reaching from the fan baffle to the top of the pile: the baffle does not have to be in the center of the load where it is hard to reach, but is just as effective if it is closer to one edge of the pile where you can reach it easier.
Some people hinge a piece of plywood or metal to the fan baffle and then have a pulley system to lift it out of the way when loading or unloading, and then, when loaded, lower the plywood or metal down to the top of the pile. It is usually segmented rather than one long piece in order to accommodate several different pile heights in the same load.
Quote from: GeneWengert-WoodDoc on April 23, 2020, 10:20:06 PM
One picture is worth a thousand words, so your video is worth many thousands.
One hint to people buildings kiln, about the top baffle reaching from the fan baffle to the top of the pile: the baffle does not have to be in the center of the load where it is hard to reach, but is just as effective if it is closer to one edge of the pile where you can reach it easier.
Some people hinge a piece of plywood or metal to the fan baffle and then have a pulley system to lift it out of the way when loading or unloading, and then lower the plywood or metal down to the top of the pile. It is usually segmented not one long piece) to accommodate several different heights in the same load.
Thanks for the helpful information👍
Nice video Robert, keep them coming,
Robert, thank you for taking the time to make the video. You have an impressive operation.
Great video! I'm not sure if I missed it, but what are you using as a heat source? I would love to see a follow up that showed the different components of the kiln and how it actually works to remove the moisture.
YellowHammer, you detailed your sterilization process with making a slow temperature drop over a three-day period to remove stresses. During your drying process, do you periodically shut the system down (fans, DH and heat - all off) to allow for similar stress relieve prior to the sterilization process?
Reason for the question is I will be running 8/4- 12/4 live edge slabs (walnut, cherry, oak, maple, etc) in my new constructed small scale DH kiln. Currently air drying first. looking for ways to keep the slabs from moving too much during my process. Have my first test load in now with slab drops just to get on understanding how the kiln will function.
For this particular kiln model, a Nyle 200M, it has a set of 4kW heat strips that provide sterilization heat, and the compressor puts out enough heat for normal operation. So for this kiln, I don't need toad supplemental heat.
When I'm drying, I'm going as fast as I can, staying just shy of the maximum drying rate for the particular species and thickness in the kiln at the time. As part of that, stresses are induced, and there are also stress from the wood itself, as well as stress from the sawing.
Typically, I will end my drying cycle at 120F and at that point I will shut off the compressor and vents. Then I will use the heat strips to run the temp up to 150F. I will typically check it 24 the next day, and if its up to temperature nice and quick, I know my wood is dry and, and I will leave everything as is for 24 hours, on the clock. Now, in reality, the core is probable already near adequate temperature, and I don't really need to wait 24 hours, but I have found that if the core is at a higher moisture level than the case, this extended higher temperature, no compressor technique will cause the wood to "sweat" where the case and the core equalize, and the moisture just stays on the surface of the wood, like perspiration. So this raises the relative humidity in the chamber and since the moisture has no where to go because the vents are closed, the case and core will stabilize at the same value.
At this point, many people will open the doors and call the load done, and I used to do that too. However, when the hot packs of wood are removed, they will start cooling and shifting and the stacks will sound like a creaky old house, as they sit on the floor. That sound is the wood changing shape as it cools rapidly, and you can literally start seeing boards bow and rear up, like they are mad. However, when I do a slow cool down, which amounts to nothing more than turning everything off for the next day. So the wood just sits there, hot, and they cools real slowly, and behaves more like a wilted vegetable. Since I also have the 3000 lb weight packs on them, they will just slowly come down to temperature, and not bow up. They end as flat as a pancake.
Great information Robert. Thank you for posting. Do you put the 3,000#s of weight on your stacks during air drying too?
No, not weights specifically, but I do stack other packs of wood on top of each other while air drying. If you look at the video where I'm tightening the strapping by hand on the air dried stacks in front of the barn, you can see how flat they are already. That is due to several factors, and many years ago when I started, these air dried packs would have looked considerably less nice.
Another thing I always do, is when I remove the wood form the kiln, I will always stack in in pairs, one pack on top of another, on the flat concrete floor and leave them like that until I remove the stickers. They key is if you can hear the packs creaking or "talking" they are still cooling and moving, so its best to keep them constrained until they quiet down. Its really a pretty cool effect, and we've had customers come into the building while the wood is talking and they always make comments about it. Just listening to the noise will tell me a lot about how the packs are doing and how they will end up.
We only have about 55" of height available in the iDry, but I just procured 3,000 lbs of granite reject slabs to build a weight sled. After watching your video, I think it will be worth it for the increased quality vs the extra space it takes up.
Still learning a lot about drying, but I've always allowed the kiln to cool down at least 24 hrs before opening it up. Just seemed like it would be a shock to the load to open it right away. After listening to your cool down technique, we feel good about the decision, but I will be paying attention to the "wood talking" sounds. Thanks again for 20 years in 20 minutes of expertise, greatly appreciated.
Using weights for flattening lumber is an excellent tradeoff for kiln space, especially for high value wood.
Quote from: YellowHammer on April 28, 2020, 01:07:14 PM
...when I do a slow cool down, which amounts to nothing more than turning everything off for the next day. So the wood just sits there, hot, and they cools real slowly...
Do you open the vents to let the warmth escape on its own (not forced)? I've done like you have, turn everything off and leave the kiln closed for a day or two. After 24 hrs its still over 100ºF in my kiln. On the second day its still about 85ºF. The last batch of firewood after sitting in the kiln for a week shut down still 'talked back' :) even as we were tossing it in the back of the trailer.
Since I'm cycling my kilns relatively quickly, I won't let the cool down extend more than the next workday, when the load has to come down and the next load goes in.
Its real important in the initial cooling period from the high temperatures, not to vent too fast, because that in effect continues the drying process, as opposed to letting the wood sweat and equalize.
Unfortunately, a lot of what I do is from from experience, doing it hundreds of times, every week, and knowing the species of wood and its tendency to warp and otherwise misbehave. What I would do with poplar isn't what I would do with cherry or walnut. Each species is different, behaves differently, can be dried differently, and some can be handled aggressively, some must be babied.
Picked up some granite slabs for weight :). I think I grabbed enough 8).
(https://forestryforum.com/gallery/albums/userpics/49257/image001~26.jpg?easyrotate_cache=1588944821)
Thanks for the video, very informative!
Jeff
JB, thanks.
Boonesyard, those weights ought to do it. The more the better. Once you start using them, you'll never go back.