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General Forestry => Drying and Processing => Topic started by: maderahardwoods on November 13, 2017, 03:27:39 PM

Title: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 13, 2017, 03:27:39 PM
Hello my name is Marco Valenzuela, and I run a small milling operation out of Los Angeles, California. I just recently finished my dehumidification kiln with a Nyle L53 dehumidification unit.

The unit is on a 4" thick slab, 2x4 construction with Hardieshingle siding, all seams sprayed with expanding foam, 2" insulation between studs, 2" insulation above studs, 10 mil vapor barrier, ½ plywood interior coated with aluminized roof paint.

The interior dimensions 161" long, 84" deep, and 86" tall, the doors are 12' wide (6' each). The unit is placed dead center at the recommended height and I added auxiliary Mechatronics fans on each side of the shelf that baffles the Nyle unit. I used Velcro along the shelf to attach to 4x8 foam sheet to baffle the load.

The DB and WB sensors are mounted on the back wall, 4ft from the ground and midway between the corner and kiln unit (recommended by Stan at Nyle).

I have about 600 bd ft of 11.5' long Claro Walnut slabs and about 250 bd f t of 7' Claro Walnut slabs, they are stickered every 18" and 1" thick (stickers).  The stacks of slabs are strapped with 3" straps to I-Beam cants.

The long Claro was dropped in July and milled about 3 weeks ago, the shorter Claro was dropped about a month ago and milled 4 weeks ago, the logs sat outside in the shade for about 1-3 weeks. Before being placed in kiln.

I tried to read the moisture content (Lignomat pinless) on the logs and could not get a consistent reading. I made sure the surface was smooth and consistent. It bounced around from 25-55%, from what I under stand any moisture content above 30% gives an inaccurate reading.

I placed the logs into the kiln last Saturday morning (Nov 4th, 2017) and set it to the recommended tier for Group 3 woods, 90 DB and 86 WB. I let the load sit all night and in the morning the WB would not get past 82, I tried to make the DB over shoot a few degrees and it still wouldn't rise the WB.

At this point I wasn't sure how the logic worked in the controller, desperate to get the compressor on I lowed the WB to 82 and the compressor kicked on, after about 24 hrs I collected about 4 gallons.  The next 24 hr cycle I collected about 3 gallons. The next 24hr cycle I collected 2 gallons. I tried to get a moisture reading everyday at the same time and I could not get a consistent reading, it pinged all over the place, from 25-45%.  I looked at the end of the slabs and did not see any new checking or surface damage.

I tried to call Nyle to get some advice.  Unfortunately the expert was out all week at a trade show, so I spoke to the other representative and he said I should likely go to the next tier, which is 100DB and 96WB.

So I set the unit to 100DB and 96WB Wednesday (11/07/2017), the next day 24hrs later the unit collected 0 water as the compressor would not come on. The WB would not go above 92, the DB had no problem getting to 100-102.

I did a little work to create a better-insulated door, I added a piece of greenhouse plastic with Velcro around the doorjamb and it really helped.  I also I used some insulation and baffled the intake vent of the power vent system.

After doing some think about the DB and WB temperatures I realized that only real factor I can control is the DB temperature with the Nyle unit (heating element) and the WB will depend on the moisture content of the wood in a controlled environment.

So Thursday evening (11/09/2017) I decided to try the next tier, so I set the DB to 110F and the WB to 96F I used an auxiliary heater to help get the DB   The unit got to 110-112 DB and the WB crept up to 96-97 which made the compressor come on (I have the compressor hysteresis set at 0 degrees, otherwise it will not start till the WB is two degrees above the DB, as soon as the DB hits the 2+ degree mark over the setting the power vents kick on dropping the WB).

I checked on the kiln Friday morning and the unit pulled about a gallon or less (from Thursday night to Friday morning), I looked at the unit and the DB was around 111 and WB was at 96, so it seems the wood and kiln like this setting.

Friday morning to Saturday morning the unit collected about 4 gallons of water, the temperature stayed right around 110-112 DB, and the WB was around 96-97.  Occasionally the over temperature vent would kick on and dropping the DB and WB temps. Killinh the compressor, but after a few minutes the kiln would warm up and restart the compressor.  I would imagine the compressor cycling on and off will allow the wood to relax a bit, which is probably a good thing.

From Saturday to Sunday morning the kiln collected about 2-3 gallons, it stayed at the 110DB and 96WB all day with the power vents cycling occasionally.

I looked inside of the kiln Sunday afternoon (Nov. 12th) and did not see anything unusual, no unusual checking, or surface damage.  The environment felt like a sauna as expected, the plastic over the doorjamb really works great for trapping the heat in.

Monday morning the unit collected about 1.5-2 gallons.

So my question is, does this seem right? I would of though the wood being so fresh would have liked the lower DB and WB temperatures recommended by the drying tables, but I understand the both trees could have been in decline and possibly had a lower MC than a healthy thriving tree.

Any constructive input is appreciated, glad I found this forum.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 13, 2017, 04:00:18 PM
 

 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_0643.JPG?easyrotate_cache=1510607121)



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_0602.JPG?easyrotate_cache=1510607198)
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 13, 2017, 04:02:48 PM
Kiln Unit 



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_0725.JPG?easyrotate_cache=1510607439)



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_0750.JPG?easyrotate_cache=1510607448)
Title: Re: Nyle L53 Kiln Start Up
Post by: WLC on November 13, 2017, 08:35:41 PM
Nothing to add other than welcome to the forum.  That's some pretty walnut.
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on November 14, 2017, 08:25:21 AM
That is a nice set up.

I do not dry from green, so take anything I say with caution.  I dry wlanut slabs that have been air dried to below 20% with the DB bulb at 120 and the WB at 75.  This keeps the compressor running constantly.  Yours is cycling on and off because the WB depression is small.  This is to keep the humidity high in the kiln to keep the drying slow. 

Because you do not know the moisture content in the slabs, you have to be conservative.  If you get below 25% moisture content, you can drop the WB setting to allow the compressor to run more of the time.  If you get below about 20%, you can run the compressor full out. 

If you want to speed up the drying a bit, keep the DB at 110 and drop the WB setting to 90.  This will keep the compressor running more but not full out. 

You might consider buying the Delmhorst J2000X with the slide hammer and the 1" pins.  That way you can check the moisture content by driving the pins into the side of the slabs and taking a reading.  This way, you will know when your slabs get below fiber saturation point, which is about 25 - 30% moisture content, then you can get more aggressive with the drying. 

Do not exceed 133 degrees on the DB with the compressor on because there a high temp shut off that will shut down the compressor.  To reset it, you have to take off the side panel and push the little green button to re-set the compressor. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 14, 2017, 12:39:26 PM
WDH thank you, it was a lot more work than I originally expected. All the details are what really consume the time.

Thank you for the information, I checked the MC of each log on Sunday and got a reading of 29% on the short log and 25% on the longer log, rechecked yesterday and got 28% and 24%.  So it looks like I am going in the right direction.

Do you prefer the in kiln Delmhorst meter to the Lignomat pinned/probe meter system?

Thanks,

Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on November 14, 2017, 04:50:46 PM
Yes.  I like the hammer probe. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 22, 2017, 11:06:16 PM
Update.

I was running the kiln at 110DB and 98WB, and the WB kept slipping down, dropped to about 93WB. So I decided to try the case hardening and bug kill step, I dumped about 7 gallons of water on the floor and raised the DB to 140F, took about 24 hrs to get to 138-140, and let it stay for another 12 hours. 

I then set the kiln to final stage of 120DB and 98WB, but it would only get to 96WB.  I talked to Nyle and they said it would be alright to lower the WB setting as the wood continues to dry.  So right now the DB is at 120 and the WB is at 93, looking like it is pulling about 2 gallons of water. 

I checked the moisture, on the two slabs and they varied from 14-20% MC.
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on November 23, 2017, 07:15:21 AM
With that moisture content, I would run my L53 at a WB of 75 so that the compressor runs full out. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 28, 2017, 06:05:34 PM
WDH, I just checked it yesterday and the shorter log was 14% and 20% (opposite ends) and the longer log was 16% and 18% (opposite ends).

I will drop the WB tonight from 92( compressor kicks on at 93), if I lower the WB to 75 the compressor runs just as hard as if it were at 80, 85, or 90 right? It just want cycle off if the WB drops below the set point?
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on November 29, 2017, 07:32:48 AM
If you set the WB at 75, it is unlikely that it will ever reach 75, so the compressor runs 100% of the time.  As I am finishing up a load, mine usually never falls below 82.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 29, 2017, 10:17:18 AM
Thank you. I switched it to 85WB yesterday, I'll check the MC this afternoon and report back. 

Thanks,

Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on November 30, 2017, 12:06:48 PM
So moisture on the two logs varies from 13-20% on where I measure. The compressor is pulling about 1-1.5 gallons/24hr cycle. 

Is this typical for walnut? I have read that claro walnut tends to dry very slowly. 

-Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 01, 2017, 07:47:43 AM
Seems right.
Title: Re: Nyle L53 Kiln Start Up
Post by: GeneWengert-WoodDoc on December 01, 2017, 10:44:36 AM
Claro dries slowly and erratically for three reasons. First, the species has varying restrictions to moisture movement.  I recall some walnut that after a year of air drying was still way over 50% MC.  Second is baterial infections that create bacterial slime that restrictions movement.  In some species, these restrictions create what are called wet pockets, or similar names.  Third is that thicker lumber does this probably due to grain angle.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 01, 2017, 05:43:41 PM
Thanks guys, good to know the 1 gallon pull in normal.
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 01, 2017, 08:24:49 PM
Patience, Grasshopper.
Title: Re: Nyle L53 Kiln Start Up
Post by: Natel on December 01, 2017, 08:38:36 PM
Crazy, I'm new to this forum and just put my first load in my woodmizer KD150 (Nyle L53) and had the same questions, and this answered almost all the questions I had. I'm in the same boat moisture ranging between 10-20% on my slabs (mixed bag of air dried stuff) my question is should I be running in a configuration that doesn't yield any water? Or are you supposed to be continually pullingwater out of the wood? Currently at 120 wet bulb and 85dry
Title: Re: Nyle L53 Kiln Start Up
Post by: GeneWengert-WoodDoc on December 01, 2017, 10:39:42 PM
At 120-85 you should be drying 1% MC loss per day typically and maybe more.  If it is not drying that fast, then the first concern is that perhaps the moisture content measurement is off...the wood is drier than you think.
Title: Re: Nyle L53 Kiln Start Up
Post by: Natel on December 02, 2017, 05:46:29 PM
You are correct, I really opened it up today and took more readings, all 5-10%. During a cycle with green Wood should I continually be getting water out of it if I'm doing everything on schedule?
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 03, 2017, 07:24:59 AM
Yes.
Title: Re: Nyle L53 Kiln Start Up
Post by: GeneWengert-WoodDoc on December 03, 2017, 06:16:05 PM
Yes, the wood should dry and moisture leaving the wood will have to get out as liquid in a DH kiln.  If the vent runs, some moisture leaves as vapor.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 07, 2017, 04:07:45 PM
Update:

Moisture content 13.5-18%, pulling less than 1 gallon  a day. 

DB 118-120 (its been cold)
WB: 86-88

-Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 11, 2017, 09:43:08 AM
So I went 24hrs without pulling a drop of water so I decided to try another case hardening treatment as recommended by Nyle. But this time I dumped about 3 gallons of water on the floor and sprayed the slabs with water directly and set the kiln to 140F.  By Saturday 3PM I was in the high 130s and by 5PM I was at 140F. 

I let the kiln sit at 140F DB (106WB) for about 24hrs, at the 24 hr mark I opened up the doors and brought the temperature down to 120F and the WB dropped back down to 85, I then restarted the compressor. 

I checked the unit this morning and not a drop has been collected in the bucket.  I am assuming a lot of the moist air escaped with the when the high temp van kicked on as well as opening the doors. 

Does anyone have some experience the can share regarding kiln drying claro walnut?

I will take some moisture readings this afternoon.

Thanks,

Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 11, 2017, 04:59:53 PM
Sounds like that you are there.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 11, 2017, 10:56:49 PM
So I took some readings after work. 

The shorter log is at: 13.3% left side, 16.4% right side
The longer log is at: 17.4% left side, 8.8% right side

WDH, do you think I am drier than I think? Possibly the pinless meter is reading inaccurately?

I am considering purchasing the Delmhorst J2000x kit. 

Thanks,

Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 12, 2017, 12:33:02 AM
Sounds normal if it was stalled black walnut.  It could also be the meter. 
If the wood is at 17% you should be able to feel it as wet simply by touching it, as well as by weight.  It will also look noticeably darker due to the moisture.  Conversely, when wood is at 8% or lower, it is noticeably dry to the touch.   

I never liked pinless meters for rough sawn lumber.  Delhmorst makes a good unit.

Considering the value of walnut, when in doubt, use the oven dry method. It's dead on, and quite fast measure the weight of a sample board of every day.   Even if you get a meter, always check it by the oven dry method occasionally.

It's hard to devise a strategy unless the moisture content is accuratly known.   

I like 150°F for stalled wood, no extra water on the floor, zero compressor.  Closed vents.  Let it stand at temp for a day or two.  Open the door and see if the wood is "sweating".  When you open the door, you will get hit with a blast of hot humid air, and will see a noticeable moisture sheen on the surface of the boards that flashes off instantly.  The moisture has come from the core of the wood and it will be drier.   

Again, this is the strategy for me on stalled black walnut. 

Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 12, 2017, 07:16:51 AM
Make sure that your compressor has not tripped from too high temp, over about 133 degrees.  Take the side panel off and press the little green button to re-set.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 12, 2017, 10:22:14 AM
Last night I switched the compressor to "off" and decided to just let the wood sit at 120F overnight to see if the WB would come back up. 

When I get home tonight I will check to make sure the compressor has not tripped and see if the wood is "sweating" at all from being at 120F overnight with no compressor.

If not, I will bump the temp to max (which I think is 140F) and let it sit for a night or two and report back.   

I am considering adding some box fans behind the stack (between L53 and lumber pile) to help pull the air through the stack.  I may just bite the bullet and buy the J2000X, it seems to be held in high regard by Nyle and the FF.  Looks like they even offer some probes to avoid opening the doors to check the moisture content.

Thanks,

Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 12, 2017, 04:31:09 PM
The J2000X happened to go on sale this afternoon on testequipmentdepot.com, price dropped from $530 to $387 so I decided to jump on the deal, should have it in about a week or two. 

Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 12, 2017, 09:17:07 PM
As WDH says, the safety trip should be checked.  Or if you can get to it, cycle the compressor on and slide the front filter up and feel the coil, it should be cold.

The L53 should get to 150°F no problem, for sterilization.

Never run the compressor over 120°F.

I used a box fan to augment airflow.  A better alternative is to cut an additional vent opening in the bottom of the unit and fit in a range hood filter.  If you do a search you will find some pics of the mod. It will blow out the dead space in the lower center of the stack.
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 12, 2017, 09:23:13 PM
I run double box fans at the back of the stack between the lumber and the back wall.  I cut the additional intake into the bottom of the unit like YH recommends.  Really helps even out the drying and it also increased the amount of water removal just a bit too.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 12, 2017, 11:08:36 PM
So I opened up the side of the dehumidification unit and pressed the reset, didn't feel any type of mechanical "click".  Moisture content is almost exactly the same as the day before.

I switched on the compressor, if I do not pull any water by morning I'll switch the compressor off and let the unit sit at 150F for 24hrs and check for water condensing on the surface. 

I will definitely make that modification to the bottom of the unit once the load is out and can pull the unit out, I will try and add some fans this weekend as well.

How cold should the coil be? I feel like I have touched it in the past and it wasn't all that cold.   

Thanks for the advice gentlemen!
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 13, 2017, 07:39:49 AM
Do this test.  Make sure that the dry bulb is over 80°.  Set the wet bulb at 75°.  Turn on the unit, compressor, and the heater.  Watch the temps while standeing by the controller.  As soon as the wet bulb temp hits 2° above the wet bulb set point, in this case 77°, begin timing using the stopwatch on your phone or use a watch.  After 5 minutes, you should hear a noticeable "click" which indicates the the compressor has kicked on.  This way, you know that your compressor is up and running.  You have to reach 2° degrees above the wet bulb set-point for the compressor to be activated, then there is a 5 minute delay before the compressor will come on. 

On the panel, if you look at the compressor, it might say "ON" on the panel.  That does not mean that the compressor is actually running.  If means that the conditions in the kiln are such that if you had the switch turned on, then the compressor would kick on in 5 minutes.  It just indicates that the system is ready.  This confused me for a while as I originally thought that "ON" on the display meant that the compressor was actually running.  When I first started running my L53, I did not know about the over-temp shut off on the compressor.  That was not in my manual.  Not understanding that, I ran the compressor while the temps climbed over 130° and it tripped the compressor.  But, I did not know that.  I thought that it was running because the display said "ON".  I could not get any water and I was frustrated.  That is when I took the side panel off to check all the wiring and connections to see if anything was loose and I say that little green button.  Not knowing exactly what I was doing, I mashed the button (pressed the button if you are a Yankee  ;D) and no click, no nothing.  Went back to the panel and turned the unit back on.  Nothing.  This was after 3 or 4 days of frustration trying to figure out what was wrong and after 3 or 4 calls with Nyle tech support.  Sat there by the control panel trying to figure out what to do next (which included sending the unit back to Nyle) and about 5 minutes had gone by and I heard a noticeable "click" from the control panel, and voila, I got water. 

On the re-set button, there is no type of "click".  If you push it all the way in, it will re-set the compressor though.  You need to make sure that your compressor is running. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 13, 2017, 10:23:19 AM
WDH thank you for that reply. 

So last night I decided to crawl into the kiln and see if the coil had any water condensing on it.  I opened the filter and could see a few drops dripping into the catch tray, I touched the coil and it was cool to the touch, but definitely not cold. I may borrow the thermal imaging camera from work and measure some temps in the kiln.

While behind the stack I felt that the airflow was stagnant, I remembered that I had one box fan in my garage and decided to place it between the stack and L53. I think I will pick up two box fans this afternoon and add them to each side of the stack to help the airflow between the slabs. 

Morning Update (Dec 13th, 2017): I swung by before work and the DB was 120 and WB was 85, I took a look in the collection bucket and I had about 1 cup of water collected, not much for 9hrs running.  I am hoping the fans will help with the water pull. 
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 13, 2017, 11:16:49 AM
Sounds like the system is working properly.  There is a high and low pressure switch in the refrigeration system.  If the compressor is operating properly, the copper line from the compressor going to the bulkhead should be cold, much like an automotive air conditioner line.  There may even be frost on it, but when properly charged, the frost should line stop at the compressor bulkhead.  There should be no frost on the coil unless the system is low of freon.   

It's very useful to listen to the sound of the compressor, and know it, as that will be a very useful diagnostic tool for you in the the future.   

The controller only calls for compressor, but is open loop, so doesn't get feedback as to what is actually happening.  If there is water condensing and dropping into the catch rail, then it is working properly.  With this particular compressor, it is almost impossible to tell of it is fully charged with a set of refrigeration pressure gauges.  In fact, to recharge the system, the charge has to be weighed in to be accurate.

You can very easily bypass the high and low pressure switch by using a small jumper at the terminal block in the DH unit.  I've had to do this several times for trouble shooting purposes.  The electrical schematics should be in your manual. 


Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 13, 2017, 04:31:56 PM
Thank you Yellowhammer.

With MC under 20% for 700-900 bd ft, how much water is typically collected in a 24hr cycle? I understand that the MC of the timber is the ultimate indicator of a healthy kiln, but I feel that the water collection bucket is a sanity check. 

I felt the surface of the boards and they definitely felt dry (and obviously warm).  It did not have that cool feeling a freshly cut slab or even an air drying slab has from the internal moisture. 
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 13, 2017, 08:35:25 PM
With a 35° wet bulb depression, you have very low humidity in the kiln.  With only that small amount of water, you have to be close. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 14, 2017, 12:58:30 PM
Gents, I noticed when the auxiliary fans are switched off that the WB temperature rises higher then when they are on. I forgot to switch the fans on last night, when I checked the kiln early this morning the WB had rises to 89, usually been sitting at 85ish. I may try power off the the auxiliary upper fans and just run a bank of three fans between the stack and L53 unit. Bumping the WB just a few degrees increased the humidity to 31% from 26%....

I should have the J2000 sometime next week. 

-Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 15, 2017, 09:38:02 PM
UPDATE:

So after 24hrs with three box fans running behind stack and two auxiliary fans running no change in water removal rate. So I switched off the compressor, sealed the vents with hard insulation panels, and set the kiln to 150F.  I will let it sit till Sunday evening and check for moisture build up on the surface of the slabs.  Wish me luck.

Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 15, 2017, 11:00:58 PM
Kind of shooting in the dark until you know your moisture content. Sweating the wood does several beneficial things:

Indicates there is moisture differential in the core, and has moved some of it to the shell.

It helps equalize the moisture levels in the boards somewhat by migrating core moisture to the shell and then the surface.

It also will also typically drop the moisture content of the wood by about a percent in a regime where a percent or two is critical.  If you dry to 7%, then sterilize, you will end up at 6% when the load cools, which is the limit where boards start to move around due to overdrying.  Flat boards will start to twist, bow and cup. 

It will obviously sterilize the wood. 

With walnut, it's not uncommon for me to stall at about 10% with wet spots at 12%.  So I jack the temps to 150°F, hold for 24 hours, then the wood will drop a percent or two to 8% to 9%, as the system cools down, and then run the compressor to get to 8% to 7% or so when it hits 120°F if I need that last percent or two.  Don't go to 6%. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 16, 2017, 12:54:36 AM
Yellowhammer thank you for the excellent advice/information. I am thinking the MC reading is close to what the meter is reading, because the meter does read consistently when placed in the same sports and has been showing a trend.  I think it had a lot of trouble when MC was above 30%, it will be interesting to compare the readings to the Delmhorst unit. 

I am wondering if the high temp. environment of the kiln affects the pin less meter reading.  I know the Delmhorst has temperature correction

Im hoping the moisture content will even out along the length of the boards.  I will definitely pop in through out the heating cycle and take measurements. 

Once you reach the end of the 150F wood sweating, do you allow the kiln to cool with the high temp vents, or even open the doors? Or do you just kill the power to the heaters and just let it come down nice and slow?

Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 16, 2017, 08:11:42 AM
I don't go in the kiln during the heating cycle, there is a chance to loose heat, and more importantly, loose moisture.  I don't like to loose moisture during the heating cycle, it could be problematic for species that are movement prone. 

Conversely, for some species, opening the door after the 24 hour heating cycle, and venting the heat the moisture, then shutting the door and continuing to heat is a good way to keep dropping moisture, similar to a conventional kiln, without running the compressor.

The cool down process is wood dependent, and I have seen different behaviors using different techniques, on different species, and what my intentions would be with the final product.  Each is also dependent on knowing the moisture content of the wood. 

Specifically, for walnut that I want to dry dead flat, and is high value, once I know the moisture content is about a percent or two above where I want it, I will let the load stay in the kiln, with the temp above 145°F for a couple days, and then let it slowly drop with the vents closed and let it "relax and be happy" on the way down.  I call it the "crock pot" cycle.  Also, for walnut, I like to put several thousand pounds of weight on it when I put it in the kiln.  I use marble scraps that are piled on top of pallets, are very heavy and thin, so don't take upon much room in the kiln.  Typically, depending on your airflow pattern, you will probably see that your top couple layers of wood will have more wave and curves than the rest of the stack.  That's lost money and extra work to fix, and a little weight will keep these top layers flat, like the ones lower down.  Heres some piles of marble as I get them.

(https://forestryforum.com/gallery/albums/userpics/21488/IMG_4407.jpg?easyrotate_cache=1513427414)

For stable white wood, or other types, I'll pull it out fast with minimum cool down.  When you do this, you can hear it moving as it cools down, creaking against the stickers, "talking" as it cools.  Since I have multiple kilns and dry about 20 different species, trying to get a load out even 7-9 days from the DH units, I can observe the behaviors of the different species on a fairly consistent basis. 

The important thing about drying for high quality is to look and observe the patterns and try different things.  Although its easy to ruin a load in a kiln, its also easy to dry wood adequately, but its more difficult to dry high value wood with minimum defects.  That's what makes it interesting.     
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 18, 2017, 09:42:09 AM
YH thank you again for the excellent information. I plan on making concrete weights in the future, but currently I am using 3" ratchet straps to secure the slabs against the 8" I-beam bunks the lumber sits on. So far it seems to be keeping the slabs flat and prevents them from falling if there was ever an earthquake or other disaster. 

So the kiln hit 140F around Saturday morning, I have been checking on the unit periodically and this morning (Monday, Dec 18th) the DB was 146F and the WB was 110F, so I am maintaining the 35 degree depression.   

I hope to hit 150F by this afternoon, but it is going slow.  I think I will cut power to heaters this afternoon and let it "crock pot" until the kiln reaches 120F, I will then  re-power on the compressor. I had Delmhorst quote me the probes and leads required to monitor the kiln from the outside to prevent unnecessary heat loss from crawling around in the unit. 
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 18, 2017, 06:52:18 PM
When I am at a 35 degree wet bulb depression, my wood is dry.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 19, 2017, 12:15:21 PM
Cut the heat from the L53 and space heater last night (DB 147.3, WB 112.8), removed extra insulation from vents (vents still closed), fans running.

Checked on it early this morning, DB was 133ish and maintaining about a 35F  depression. 

Stuck my hand in through the vent, it did not feel humid in the chamber. 

-Marco

Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 19, 2017, 01:18:15 PM
Ball game. 
When is the meter coming in?
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 19, 2017, 01:56:19 PM
I was hoping this week, but looking like early next week.  I may just let the kiln cool down to ambient until the meter arrives. 

-Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 19, 2017, 04:07:35 PM
Just called Test Equipment Depot, I added 2-day shipping. Hopefully it arrive this Friday. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 19, 2017, 11:34:22 PM
Just checked on the kiln, the DB is 123F and the WB is at 98F. The wet bulb jumper up 10F! I decided to switch on the compressor. 

I peaked into the chamber and did not see any "sweat" on the boards, but I am hoping the pores of the board opened and will allow the hard water to come out.

I should have the meter Thursday evening, just got the tracking number. 

I will take some MC readings tomorrow with my pinless, can't wait to compare results. 

-Marco

Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 20, 2017, 01:44:01 AM
UPDATE: Looks like it was a fluke, I went into the kiln to see if the coil was cold and noticed the wick on the WB thermometer was withered.  I cut a piece of wick and made sure it was wet. 

The WB then dropped to the 80's where it was.  The wood does not have that wet cool feeling fresh wood has, I am dying to get my J2000x.
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 20, 2017, 07:06:14 AM
My money says that you are there. 
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 20, 2017, 01:37:53 PM
I'm worried maybe a little too dry.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 20, 2017, 06:45:00 PM
I hope not, the wood did not look any more stressed than usual (same checking).  I cut power to kiln completely last night to allow the wood to slowly come back to ambient. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 21, 2017, 01:22:10 AM
UPDATE: The wood is definitely not dry.  I opened up the kiln and everything looked and felt great on the surface.   

I decided to cut the last 6" off of the top slab to take a look inside the slab...I took the cut and could feet that the end grain was wet, it had a cool feel to it.

I took the chunk home and split it in half and feel the water sprinkling on my hand, the freshly cut surface felt similar to a freshly milled slab.

Not really sure how to proceed, I have read that claro walnut could be difficult. 

Any input is appreciated, I may try and give another mill a call and see if they have any advice. 

Thanks,

Marco

Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 21, 2017, 07:41:05 AM
That's crazy.  What is the WB/DB now?


Title: Re: Nyle L53 Kiln Start Up
Post by: boardmaker on December 21, 2017, 08:36:24 AM
I skimmed this post pretty quickly, but it looks like you still haven't done an oven test.  Correct?
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 21, 2017, 09:38:14 AM
I actually powered off the kiln completely, before then the DB was 120-122 and the WB was in the mid-80s. 

I should have my Delmhorst this evening, I have not done an oven dry test.  But I may try it today if I can borrow a precision scale from my brother. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 23, 2017, 12:13:57 AM
Where do I begin....

I got the delmhost and went over to the kiln to take some readings.  I started with the top slab on the short stack, it varied from 13-15%.

The slab underneath it read anywhere from 45-50%.  The large slab varied from 45% to 12% on the far end. 

So I decided to ask a few sawyers/kiln operators who strictly deal with live edge slabs,  a gentleman in Minnesota was very friendly and willing to share some tips with me, I will share what he told me with you.  It was somewhat hard to hear him with our connection, so I may amend this information in the future. 

If you want the sap wood to really "pop", allow the slabs to sit in the sun for 1 day per side to oxidize
Use and electric planer to plane the sapwood 1/64 below the heart wood
Coat the heartwood with a 50% mix of Anchorseal and water.

He told me the slab drying process is not like the board drying process and that it is much much longer.  He allows the boards to air dry until they reach 25% (need to re-verify). 

Once in the kiln for final dry he said it is normal for the compressor to rarely come on, the wood will sit at 120F and slowly draw the water from the center.  The moist air escapes from the imperfections in the kiln, but he said occasionally the compressor will come on if the WB hits the set point of 95.  He follows this process until dry. 
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on December 23, 2017, 07:41:43 AM
I also pre-dry my 9/4 slabs under the air drying shed until the moisture content falls below 20%.  I do not have any problems getting them under 10% in about 10 days in the kiln with the DB at 120 and the WB at 75.  I have never attempted to dry them green in the kiln.
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 23, 2017, 08:44:14 AM
I also typically air dry my walnut slabs for months before I DH kiln them as it doesn't make sense to commit the excess kiln time to dry green.  I have a specific building dedicated for air drying slabs.  However, I have also dried them (walnut) in the kiln with only a few weeks in the air drying shed when I really need some out.  I also use my solar kiln, and will dry pretty much every species from green in there, takes several months, then finish them in the L53.  I regularly dry 9/4 poplar, basswood, pine, soft maple from near green in the L53.  In these cases I will flash off the surface moisture with blowers to prevent sticker staining.  I have also experimented and slipped a few pieces of 9/4 walnut into my 4/4 stack as an experiment in my L53.  The 4/4 acted as ballast and prevented the 9/4 from drying too fast.

Its very important to know the species' drying behavior, max moisture removal rate, etc.  I've never dried Claro Walnut, but Appalachian Black Walnut can tolerate 8% moisture loss per day, 4/4, so probably 4% for 8/4, and its pretty hard to get that rate with a DH kiln, so I've had success with it.  The kiln generally can't remove moisture faster than walnut can tolerate, especially at the lower MC's.  I don't use long probes with thick walnut, the oven dry method is the best, surest way to to see how the core is drying in relation to the case, as demonstrated in this case.  I will stick the case with the Delmhorst to see what the case MC is, and compare it to oven dry for overall results. 

I've never heard of the the techniques described using a hand planer.  Seems like he has a system that works for him.  It seems counterproductive to seal the heartwood, which is where the wet pockets would be most prone to stall.  Why seal the wood to protect from excess moisture removal when that is the very problem, i.e. moisture removal is too slow.  Again, its important to know the characteristics of Claro to develop or optimize a strategy specific to it.  There may be some historical literature on the subject.

One thing that jumps out at me is that your top slab was 30% dryer than the slab underneath.  This is a very important clue.  Why did this happen?  What was different about it?  Heartwood/sapwpood ratio, thickness, etc?  What about the kiln geometry?  Typically, a differential drying on the top layers my DH kilns indicates more airflow and more exposure to the airflow to transport moisture.  I typically see this on the top layer if it is fully exposed to the airflow.  Normally, I cover my top layer with a light canvas tarp to restrict excess airldfow across it.  In your case, it might indicate that the airflow across the top was more optimized.  Were there defects in the top slab indicating excess drying rate?  The effect of airflow/velocity is well know, and it is proportional to the moisture content of the wood.  The higher the airflow and the higher the moisture content of the wood, then the more moisture will be removed.  As the wood dries, the moisture removal rate decreases.  Thats why many folks, like myself and WDH use air drying sheds as the fans will remove moisture as fast as the wood can tolerate, without tying up the kiln.  So I would say, without more information or a clearer visualization, that there is as airflow issue which caused the top layer to dry faster than the other layers.  It could be the baffling or a stagnant airflow through the pack.  In addition to the two fans in the L53, I have added 4 fans to the horizontal baffle, and cut another intake on the bottom of the kiln, to blow out any dead spots.  I have a total of 6 fans across the length of the baffle.  I used an anemometer to measure airflow though the layers to make sure it is consistent and uniform when I first setup the kiln and to make sure my baffling was effective.  Where is your baffling?  On top, sides, bottom?  The top slab behaved more like what I would have expected.  If the top layer was only one slab, it may be the properties of that particular piece of wood, if it was two slabs, then its a kiln condition issue.  The information that there is such large differences in moisture across the length of the second slab also indicates an airflow problem. However, it would be useful to understand where the wet and dry areas were in the wood.

Some detective work is in order.  That's what makes kiln drying interesting.   
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 24, 2017, 08:03:53 PM
Yellowhammer and WDH thank you for the excellent responses and information, you have really help keep me grounded.  There aren't a lot of sawyers let alone kiln operators in my neck of the woods. 

I was a little nervous about placing such freshly milled boards in the kiln for drying, but Stan a Nyle mentioned many people place freshly milled slabs in the kiln to fully control the drying process.  I understand it isn't the most efficient, but I really need to get my first load out to have product to move.

I am currently air drying all of the slabs I have milled under the shade of a large orange tree out of direct sunlight. All slabs are placed on leveled cants and are ratchet strapped down to keep the slabs flat. I will be purchasing some mesh tarps to keep any debris of them, and when it does rain I will cover them fully with a tarp.  I will just have to make this work, I have plans on building a drying "patio" in the future. 

I really can't speak to the sawyers methods in Minnesota, but it does seem like it is working for him. He produces some gorgeous flat slabs.  The contrast between the sapwood and heartwood is amazing. 

After taking the measurements and seeing the discrepancy between the top slab and lower slabs I am inclined to pull them out of the kiln and shuffle the top to bottom.  Until just recently I was using two foam panels to baffle the slabs, but I switched to two sheets of 1/4 plywood as they are less prone to moving, I use pieces of plywood to baffle between the kiln walls and the slabs. About two weeks ago I added three box fans between the back of the slabs and the L53 unit.  The top baffle has two auxiliary Mechatronics fans blowing towards the doors with a slight angle. 

All slabs are cut at 9/4 with exception to one or two that are typically on the bottom of the log when milling.  It seems really odd that I got measurements in the 40-50% range, as I took a few measurements from slabs (also claro walnut) that have been air drying for a few weeks and got readings in the 35-45% range.  It may be time to purchase an anemometer to maximize my kiln design.

Do you have problems with the fans moving the canvas in the kiln? The foam was so light that occasionally the pieces would shift, the plywood seems to have solved this problem.   

When it comes to oven dry samples with slabs, do I need to rip the slab in half? Or can I take a cut 12" from one end across the gran and use that piece as my sample?

I am determined to find a drying schedule that will work for Claro, as I have 1000's of bd ft of walnut to mill and dry in the next few months. 

Once again thank you for the great information, great community!

Merry Christmas!

-Marco




Title: Re: Nyle L53 Kiln Start Up
Post by: PC-Urban-Sawyer on December 25, 2017, 12:46:17 PM
Marco,

I think one problem you have is relying on meters to determine moisture levels.

As I understand it, even the best quality meters are not reliable at higher moisture levels. I think the cutoff point seems to be in the 30 percent range.

On the other hand, using the oven method to determine moisture level seems quite reliable if you have an accurate set of scales for the range you are weighing.

Good luck!

Herb
Title: Re: Nyle L53 Kiln Start Up
Post by: GeneWengert-WoodDoc on December 26, 2017, 09:22:06 AM
Under 30% MC, the Delmhost pin meter has been confirmed to be within 1/2% MC or better for North American.species, if they are used correctly with insulated pins driven 1/4 the thickness, etc.

The oven test requires some care as well...215 F until weight loss stops and a scale or balance that measures to two decimal places.

For example, if the sample weighs 55.0 grams and the oven dry weighs 50.0, the calculated moisture is 10.0% MC. However, with two digits, the weights are 55.05 and 49.95.  This gives 10.2 % MC.  So, with one digit, we have an uncertainty of around Plus or minus 0.4% MC.  With no digits, the uncertainty is 4% MC.  This assumes the balance is working perfectly and is properly calibrated.
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 26, 2017, 10:10:51 AM
For oven dry samples, I usually have at least one slab that has a poor end, or one with cracks, or one that will need future dressing.  So I cut samples off and weigh them and write in on them on the samples with a Sharpie.  Once the preliminary weighing and drying are done, the only thing that is required to get a new moisture content is to take the piece and put it on the scale and run the calculation.  I determine the new MC, write it on the sample piece, and put it back in the kiln.  I keep the scale in the kiln controller box, so the whole process only takes a minimal amount of time.  I've got a slide hammer for my Delmhorst but I prefer to weigh thick slabs, just because I know its right, and its fast and easy.  I use a food scale, $25 or so at WalMart.  The sample pieces are relatively small, and would be trimmed anyway.

I use 2 inch foam as a baffle from the horizontal fan deck to the lip of the forward lumber stack in the kiln.  I don't like to have free air blowing over the top layer, so I try to simulate a layer of wood on top of it.  I use canvas and stickers to weigh it down.  I've also used burlap, and even corrugated metal roofing, the same way I cover the top layer of wood in the solar kiln.  Sometimes I'll even use the foam board.  Just depends on what seems to wok best.  Its very helpful to standardize the lumber height of the stack so once the configuration is optimized, I don't have to play much with it on successive loads.  By the way, if you have found that due to the inlet plenum size of the stack (from of pressure side of the stack to nearest wall) is causing a significant pressure drop and air flow reduction across the face of the stack, and causing the air to cheat, the burlap sheet technique is a good way drape over the upper layers and force air to go down to the lower level of wood in the stack.  If thats the case, then it should be a temporary measure and either the kiln or stack geometry should be addressed on successive loads.

Typically, most of this aggravation is goes away with pre air drying as kiln airflow and velocity have much less influence as the wood drop MC. 

   
 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on December 26, 2017, 11:33:31 PM
Thank you guys guys again.  I think I will take 12" off one of da longer and shorter slabs and use dat as disguy's core sample. 

I think yoozguys may be on ta something, I wonder if having da shorter slabs centered on da longer slabs with side baffling is causing some issues. I will take some updated photos of da stack and baffling tomorrow. 

Thanks,

Marco
Title: Re: Nyle L53 Kiln Start Up
Post by: xlogger on December 28, 2017, 06:19:55 AM
Quote from: YellowHammer on December 26, 2017, 10:10:51 AM
For oven dry samples, I usually have at least one slab that has a poor end, or one with cracks, or one that will need future dressing.  So I cut samples off and weigh them and write in on them on the samples with a Sharpie.  Once the preliminary weighing and drying are done, the only thing that is required to get a new moisture content is to take the piece and put it on the scale and run the calculation.  I determine the new MC, write it on the sample piece, and put it back in the kiln.  I keep the scale in the kiln controller box, so the whole process only takes a minimal amount of time.  I've got a slide hammer for my Delmhorst but I prefer to weigh thick slabs, just because I know its right, and its fast and easy.  I use a food scale, $25 or so at WalMart.  The sample pieces are relatively small, and would be trimmed anyway.

I use 2 inch foam as a baffle from the horizontal fan deck to the lip of the forward lumber stack in the kiln.  I don't like to have free air blowing over the top layer, so I try to simulate a layer of wood on top of it.  I use canvas and stickers to weigh it down.  I've also used burlap, and even corrugated metal roofing, the same way I cover the top layer of wood in the solar kiln.  Sometimes I'll even use the foam board.  Just depends on what seems to wok best.  Its very helpful to standardize the lumber height of the stack so once the configuration is optimized, I don't have to play much with it on successive loads.  By the way, if you have found that due to the inlet plenum size of the stack (from of pressure side of the stack to nearest wall) is causing a significant pressure drop and air flow reduction across the face of the stack, and causing the air to cheat, the burlap sheet technique is a good way drape over the upper layers and force air to go down to the lower level of wood in the stack.  If thats the case, then it should be a temporary measure and either the kiln or stack geometry should be addressed on successive loads.

Typically, most of this aggravation is goes away with pre air drying as kiln airflow and velocity have much less influence as the wood drop MC.
 
Robert I've been thinking about weighing samples which I not done in the past. I was reading in the Nyle book what formulas to use. How big of a piece of slab do you cut off? If you can would you take a quick picture of it next time you get a chance.
Thanks

   

Title: Re: Nyle L53 Kiln Start Up
Post by: GeneWengert-WoodDoc on December 28, 2017, 09:38:15 PM
The technique of using sample boards is well documented in Drying Hardwood Lumber...available on line from many sites.
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 28, 2017, 10:02:00 PM
This is the kind of trim I use and cut for kiln samples as I put in a load.  I don't cut regular or textbook sized pieces, just whatever is representative of the load, large enough to get a decent measurement, and what seems to makes sense.  Cut out an irregularities, cracks, pith or anything else that may make the sample non representative.  Then I take the piece and half it, and use one for the oven sample, and one for the kiln sample.  Since these are walnut, I re-use the sample boards and saw them into small, sellable pieces, maybe 2"x4"x12" or similar when the load is done and I'm not wasting wood or money.  Personally, I learned a lot when I first did the technique, and it really is pretty easy.  It also takes out all the guesswork and will answer lots of question about the accuracy of your meters.  Take a weight, calculate a MC, and then check it with the meter.  I have done this many, many times, and it has proven invaluable.  Lets just say, I originally had three different types of moisture meters, and I had no confidence in any of them.  In very short order, I finally believed one of them, and the other two were literally tossed in the garbage can.   
(https://forestryforum.com/gallery/albums/userpics/21488/1DEF6C5C-BCBF-45F4-97F9-732CE51417AE.jpeg?easyrotate_cache=1514511935)
Title: Re: Nyle L53 Kiln Start Up
Post by: xlogger on December 29, 2017, 04:41:14 AM
Thanks Robert, next week it's going to really cold here so I'll have time to figure this out I hope. Maybe need to go further south to your place and look and learn. ;D
Title: Re: Nyle L53 Kiln Start Up
Post by: GeneWengert-WoodDoc on December 29, 2017, 07:10:19 AM
Robert makes a key point...we are concerned about the MC of the useable wood, so moisture samples should not have defects.  We want the samples to represent the other good and expensive pieces in the load. 

As samples are typically full width and 30" long, they are end coated with a coating that will stop moisture loss from the ends (making them behave like they are long pieces of lumber) and will not melt off.  Paint is not good enough, Anchorseal end coating melts but their BOSS product is perfect, roofing tar is ok too, and there are a few other brands of sample end coating.  To get the samples' initial MC, we cut 1" long pieces from each end before end coating and weigh, oven dry, reweigh, and calculate the MC.  The average of the two small pieces is the estimated MC of the 30" sample board.

For wetter the stock, the sample needs the same air flow, RH, and temperature as the rest of the lumber in the kiln.  For 25%MC or lower, air flow can be different as variation in air speed does not affect drying speed at lower MCs.

Using this technique, any time you need the current MC, weigh the sample board and calculate the MC in seconds.  YH even has a computer spreadsheet that does the calculations for you.
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on December 29, 2017, 09:33:08 AM
Ricky,
Come on by anytime. 
I have a spreadsheet I made years ago that does the calculations, and automatically graphs the moisture drop. 
 
If anyone wants it, send me a PM with your email and I'll send it to you. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on January 01, 2018, 09:45:07 PM
Update:

Oh man what a week, my wife came down with a serious stomach flu and was out from Tuesday evening to Friday evening.  While at the same time this was going I had to replace 90ft of water main line which required the cutting and patching of 40ft of concrete. 

Wife is finally back in action and water line at my dads place is patched and leak free so far. 

So Sunday morning I opened up the kiln completely with intentions to rearrange all of slabs from top to bottom and measure the moisture content of each slab in three places (far right, center, and far left).

I started with the slabs on the top stack, they were pulled out and rearranged, all of the moisture contents are captured in the photo below.  I then moved on to the long slabs, after the third all of the moisture contents were reading from 45-60% so I decided there was no point in rearranging the 12ft pieces. 

The first photos show the original arrangement of the kiln, I had the shorter slabs centered on the longer slabs with the sides baffled.  I decided to maximize the kiln charge and place some smaller pieces to side of the shorter pieces, which also made it easier to baffle. 

I really have no idea how the 12ft slabs are still 45-60%+ moisture content, they have been in the kiln for almost two months.  Do I have extreme case hardening? Is Claro Walnut just a slow drying wood?

I am considering asking a local hardwood processor if they are willing to sell time on their vacuum kiln as I really need to get some dry wood to market.

Slabs are currently at 120DB with the WB at 85, just going to try and follow the advice from the sawyer from Minnesota for the time being. 

I thinking about coating the slabs with pentacryl, I have read that it prevents the crotch grain and figure from drying to quickly and can also speed the drying up by 30%.  I have had some issues with the crotch grain drying to quickly and checking/"collapsing". 

Once again any help is appreciated. 



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1112.jpg?easyrotate_cache=1514861151)

Original Stacking



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1094.JPG?easyrotate_cache=1514861072) 

 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1120.JPG?easyrotate_cache=1514861296)



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1129.JPG?easyrotate_cache=1514861379) 



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1132.JPG?easyrotate_cache=1514861477)



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1143.JPG?easyrotate_cache=1514861513)
Title: Re: Nyle L53 Kiln Start Up
Post by: WLC on January 01, 2018, 10:20:47 PM
I know absolutely nothing about drying in a DH kiln, but it seems to me that they would've air dried to a lower MC (especially in you CA climate) than that in two months if they had been stacked outside under a shed.  Something must be "off", what it is I have no idea.
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on January 02, 2018, 12:58:06 AM
Did you baffle the skids?  Floor to first layer?

The plastic sheet drops down to cover the doorway?  I haven't seen that before, not sure what purpose it would serve? 

The side baffling looks fine. 

I can't see behind the plastic to see the fans clearly?  Mine are mounted horizontally through the fan deck, blowing toward the ceiling.  Yours are near vertical?  With the sheet down and the doors open, you should see a very pronounced billow of the plastic sheet out the door as the air is pushed along the ceiling, against the plastic sheet, down the front of the stacks, and forced through the the stack.  The billow would be caused be the back pressure forcing the air through the front of the stacks. 

I like the steel runners.

Thats some pretty wood.

   

 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on January 02, 2018, 02:28:24 PM
I have not baffled the skids, I will do that next. 

I used the plastic sheet to help insulate the door, it has really helped keep the temperature stable.  It is also great at preventing heat loss in when I open the chamber door(s) to check the moisture content. 

The fans are near vertical, I gave them 5 degree kick towards the ceiling (leaning backwards toward rear wall). I will snap some photos of the current fan configuration tonight.

I like your idea for fan baffling and will convert to this style this weekend when I baffle the metal skids.  You haven't had any issues with the fans pulling air that has not been processed by the Nyle unit?

When I open the door to enter the kiln I definitely see the plastic being pushed out, I will take a photo with the doors open and all fans running. 

Thanks for the great tips!

PS: Has any one played with baffling behind the stack? Something shaped like a funnel with fan stacks along the length? It might be easier if i draw it out. 
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on January 02, 2018, 08:28:03 PM
Here is a pic of my L53 fully baffled. 



 (https://forestryforum.com/gallery/albums/userpics/14370/IMG_1288.JPG?easyrotate_cache=1514942676)

I plug every hole that is not a stickered layer of lumber.  Air will preferentially go through the largest gaps and holes, so plugging every opening that is not a stickered layer of wood forces all the air through the wood layers and evens out the drying from the top to the bottom of the stack.  My auxuillary fans are mounted at a 45 degree angle to the ceiling.  With the two in the unit, I have 6 fans altogether. 
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on January 03, 2018, 12:25:16 AM
Great looking setup WDH. 

Here are some photos of my fans, the doors open with the fans on, and finally the current DB and WB temps.



 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1144.JPG?easyrotate_cache=1514957024) 

 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1146.JPG?easyrotate_cache=1514957028) 

 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1147.JPG?easyrotate_cache=1514957085) 

 (https://forestryforum.com/gallery/albums/userpics/47577/IMG_1148.JPG?easyrotate_cache=1514957097)
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on January 03, 2018, 01:18:30 PM
Quote from: maderahardwoods on January 02, 2018, 02:28:24 PM

I like your idea for fan baffling and will convert to this style this weekend when I baffle the metal skids.  You haven't had any issues with the fans pulling air that has not been processed by the Nyle unit?
No since the system is not a single pass environment, its very important to get a fully toroidal, circular mixing airflow path in the kiln, low pressure to high pressure across the entire stack, across the face.  This also eliminates any need for further baffling.  The main thing is to do as WDH shows, close off any path where the air can short cut around the stack, which it will do readily, as the wood acts as an obstruction and the air will simply go around, it allowed.  That's one reason I like to use foam, both 2 inch and 1 inch, because the better the stack gets sealed the more the foam gets sucked in the stack due to the pressure differential.  You mentioned you had foam blowing around, it should get almost sucked into place, which is one reason to baffle on the high pressure, intake side of the stack.

 
Title: Re: Nyle L53 Kiln Start Up
Post by: WDH on January 03, 2018, 08:38:01 PM
Your auxillary fans just seem to be mounted on top of the back table that closes off the top of the dehumidification unit, and they do not seem to be pulling air from below the table, air that has been through the wood stack.  If you look at my auxillary fans, they are mounted in boxes.  Below each box, directly under each fan, there is a 9" diameter hole in the table allowing the fans to suck the air from behind the lumber stack below the table and blow it back to the front of the kiln, creating a continuous circular air flow over the top of the baffle, through the wood layers and sucked back up through the holes in the table and so on.  The two fans in the unit blow the air that has been through the condenser out towards the back side walls, and the auxillary fans blow that air directly to the front of the kiln to be circulated through the wood layers.   
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on January 03, 2018, 10:52:43 PM
This a picture of my larger kiln deck, except it is a vertical wall instead of horizontal.  Notice the fan opening are cut in the barrier itself, to get the circular airflow pattern
(https://forestryforum.com/gallery/albums/userpics/21488/IMG_0544.JPG?easyrotate_cache=1428631275)
Title: Re: Nyle L53 Kiln Start Up
Post by: xlogger on January 06, 2018, 06:27:47 AM
Robert, I was looking on Amazon this morning for scales. I read somewhere but can't find it now how low of weigh it needs to go, 1 gram? If it goes up to 10 pounds do you think that should be plenty for thick slabs also?
Also do you try to oven dry sample board off mill or does it matter if you do it later?

Ricky
Title: Re: Nyle L53 Kiln Start Up
Post by: GeneWengert-WoodDoc on January 06, 2018, 08:04:46 AM
You need two scales or balances.  The small one weighs to 1/10 gram and is for the moisture sections that weigh around 50 to 100 grams and are oven dried..  If you only weigh to 1 gram, you will have an accuracy of around 3% MC.

The second one is for the large samples and 10 pounds or 5000 grams or 5 kg capacity is good.
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on January 06, 2018, 09:01:10 PM
Quote from: xlogger on January 06, 2018, 06:27:47 AM
Robert, I was looking on Amazon this morning for scales. I read somewhere but can't find it now how low of weigh it needs to go, 1 gram? If it goes up to 10 pounds do you think that should be plenty for thick slabs also?
Also do you try to oven dry sample board off mill or does it matter if you do it later?

Ricky
My sample board is typically about the same size, give or take, as the oven board.  Small enough to fit in the oven, big enough to get in the sweet spot of the scales.

Since its important to make sure the sample boards are representative of the lumber stacks, I typically work the sample boards as I'm putting the stack in the kiln.  I grab my battery operated circular saw and whack them out real time.
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on January 16, 2018, 09:07:14 PM
Update:

Fan baffle has been modified as shown below, will try and baffle all of the floor beams this weekend.  I may build an angled housing for the fans to live in the near future.  But I figure with the fans pointing up and the baffling the air should be forced into the stack. 

I also decided to experiment with the shorter slabs, I pulled them out and coated them with Pentacryl, it took about 2.5 gallons to thoroughly coat 11 slabs front and back. 

I replaced them back into the kiln yesterday and went back on this evening to check in on them.  The DB was right at 120 and the WB bumped up to 93.3 degrees, a jump of about 6 degrees from it has been averaging. I refilled the WB wick water tank yesterday so I am pretty sure the temperature is correct.  I did not take any MC of the slabs, but will this coming weekend. 

I am wondering if the Pentacryl is pushing the water out and increasing the humidity which in turn raised the WB temperature.  Or if the Pentacryl has some water base that is vaporizing off. Hopefully this is the silver bullet I need. 

Thanks gang!

(https://forestryforum.com/gallery/albums/userpics/47577/IMG_1191~1.JPG?easyrotate_cache=1516155189)

(https://forestryforum.com/gallery/albums/userpics/47577/IMG_1192~2.JPG?easyrotate_cache=1516155419)

(https://forestryforum.com/gallery/albums/userpics/47577/IMG_1230~1.JPG?easyrotate_cache=1516155172)

(https://forestryforum.com/gallery/albums/userpics/47577/IMG_1232~1.JPG?easyrotate_cache=1516155142)


Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on January 18, 2018, 10:22:14 AM
Update:

The WB has dropped back down to 85F. 
Title: Re: Nyle L53 Kiln Start Up
Post by: YellowHammer on January 18, 2018, 01:17:22 PM
I have no experience with Pentacryl.  I don't know how it will affect the drying. 

Be careful with the little milk parlor heater, I had one in my kiln, and in fairly short order the fan corroded and stopped working and the heater coil overheated and shorted out.  Could have easily burned my kiln down.  I personally prefer sealed halogen work lights for extra heat.   
Title: Re: Nyle L53 Kiln Start Up
Post by: maderahardwoods on April 17, 2018, 05:28:49 PM
Guys, it has been a while.  So I decided to pull the walnut out of the kiln and to let it air dry for year or so.  

Since then I have had good luck running softwoods though the kiln as well as getting hardwoods slabs that are 12-15% right to 7-8%.  

I have some really pretty burled elm and bastogne walnut in the kiln. I'll post some photos soon. 

Thanks!
Title: Re: Nyle L53 Kiln Start Up
Post by: rjwoelk on December 27, 2018, 04:15:42 PM
How are things going? read the thread. Very interesting.