This is my first post in Drying and Processing so I hope y'all will forgive me if I sound dumb. I'm not dumb but quite often ignorant. :) I have an early Nyle L200 kiln in a self (over) built chamber that is nearly air tight and very well insulated. I haven't used the kiln in several years but I have been planning to put it back to work. A couple weeks ago a man called and asked about drying 1800 board feet of pecan- 3 inch live edge slabs and 4x4's all 12 feet long. I agreed to undertake this job before researching fully. As it stands now my kiln is loaded and operating properly. After searching this forum and learning how long YH and Dr. Wengert and others think it will take to dry thick pecan, I talked to the customer (great guy) and we agree to put the time and effort into this load for ever ever how long it takes. Probably not much profit for me but that's ok.
Where I'm at now after 2 days the kiln is at 92 degrees and 85% RH with compressor operating at 5%. I'm using a sling psychrometer presently but have an electronic sensor ordered to simplify keeping up with conditions in the kiln. My Nyle controller only sets temp and compressor on time manually, so I think this sensor will be a big help.
My question after the long explanation is this: Does anyone know or are willing to make an educated guess as to how to proceed through a schedule or exactly what to monitor to best assure good results drying this load? The tree was blown down during the last hurricane and came from family homestead in Fairhope Alabama. The family wants to build a table and probably other furniture from it.
I understand it may well take 4 months to dry. but that's ok as long as it turns out good.
Thanks in advance for your help getting through this endeavour!! If additional info is needed just ask. I assure you I will keep up with this thread every day.
Was this green wood going in?
If so you are looking at 18 to 20 weeks for the 3" and you don't to pull more than 1% per day.
For 4x4's you are looking at 45-50 weeks and don't pull more than 1/2% a day till you are below 35% moisture then no more than 1%.
Quote from: K-Guy on February 03, 2021, 11:26:27 AM
Was this green wood going in?
If so you are looking at 18 to 20 weeks for the 3" and you don't to pull more than 1% per day.
For 4x4's you are looking at 45-50 weeks and don't pull more than 1/2% a day till you are below 35% moisture then no more than 1%.
Yes wood was sawn last Friday and loaded Saturday. I have a moisture meter that I got from Nyle with my kiln- electrophysics- that supposedly goes to 99%, but most everyone on here says that above 40% meters are terribly inaccurate. Would y'all still have the manual for that meter? I didn't see a model number. Is there any other way to monitor rate of drying without knowing precise moisture content of wood? I have a Delmhorst J2000 on order for later use.
Thanks for your help KGuy!!
By the way, as of 3:20 this afternoon Kiln temp was 94 RH was 89% and most all wood showed 99% mc with no degrade seen.
When I dry thick hardwood from green in my L200, I have to add RH% to my kiln for the first 50 days or so in order to prevent it from drying the lumber too quickly. I add the RH% via a high pressure fogging system.
You might want to add a bucket under your kiln drain so that you can measure the amount of water removal.
Another option is to only run the kiln for a few hours a day, so as to minimize water removal. Keep the fans on though.
Drying 3" thick green pecan ( smiley_devil) in a kiln? Oh goodness, I will not be able to sleep tonight for the nightmares taz-smiley whiteflag_smiley smiley_devil_trident smiley_alcoholic_01
"Sleepless in Hawkinsville"
Will it stream on Nyle Netflix? popcorn_smiley
Quote from: scsmith42 on February 03, 2021, 08:41:05 PM
When I dry thick hardwood from green in my L200, I have to add RH% to my kiln for the first 50 days or so in order to prevent it from drying the lumber too quickly. I add the RH% via a high pressure fogging system.
You might want to add a bucket under your kiln drain so that you can measure the amount of water removal.
Another option is to only run the kiln for a few hours a day, so as to minimize water removal. Keep the fans on though.
Am I safe as I'm doing as long as there is no visible degrade showing? Compressor is now on 5% as stated above. RH is right around 89 to 90% at 92 to 94 degrees. Measuring water output is very difficult if not impossible due to installation. Drain runs to daylight outside.
Why don't you just let it air dry for good while to let nature gently remove much of the moisture instead of tying up you kiln for months and months for only one load?
Quote from: KenMac on February 03, 2021, 09:33:41 PMAm I safe as I'm doing as long as there is no visible degrade showing?
No. The tension won't necessarily show till you get to 15-20% when it shows up bad. The wood may contain it till then.
Who is the moisture meter manufacturer and what model number? I might be able to get you a manual.
Quote from: KenMac on February 03, 2021, 09:33:41 PM
Quote from: scsmith42 on February 03, 2021, 08:41:05 PM
When I dry thick hardwood from green in my L200, I have to add RH% to my kiln for the first 50 days or so in order to prevent it from drying the lumber too quickly. I add the RH% via a high pressure fogging system.
You might want to add a bucket under your kiln drain so that you can measure the amount of water removal.
Another option is to only run the kiln for a few hours a day, so as to minimize water removal. Keep the fans on though.
Am I safe as I'm doing as long as there is no visible degrade showing? Compressor is now on 5% as stated above. RH is right around 89 to 90% at 92 to 94 degrees. Measuring water output is very difficult if not impossible due to installation. Drain runs to daylight outside.
As Stan already replied, no.
Moisture meters are not viable on green lumber. The only two choices that I can think of are to measure the weight of the wood or the amount of water removal.
The success rate is very low for drying high quality thick lumber from green in a kiln. You cannot rush it and expect high quality results. In most instances you're taking steps to slow down the kiln drying process instead of speeding it up.
Just to include this as an interesting bit of info- I turned my compressor off and left the fans on at about 10:00 am this morning with the temp at 95 degrees. At 3:00 pm I turned it back on momentarily just to see what the temp was. It was still at 93 with no heat source. I knew it was well insulated but that kinda shocked me. This morning's reading were: 95 degrees- 94%rh. I'm going to talk to the wood's owner to see how he want to proceed. Thanks for all of your advice and humorous ridicule. ;D lol
Probably get a manual for your Electrophysics from.......Electrophysics Moisture Meters (http://www.electrophysics.on.ca/)
I have a 25 year old MT808 with a manual. If its the manual you need let me know and I'll try to scan it or something.
Quote from: Larry on February 07, 2021, 08:37:57 PM
Probably get a manual for your Electrophysics from.......Electrophysics Moisture Meters (http://www.electrophysics.on.ca/)
I have a 25 year old MT808 with a manual. If its the manual you need let me know and I'll try to scan it or something.
Thanks, Larry. I got the manual from Electrophysics in a pdf. The meter has always been very reliable and accurate as far as I know. I just didn't know where to set the density for various species.
As an update for any of you who want to follow my journey into disaster, The owner wishes to continue maintaining 90 degrees and 90% RH for a while and see how things are looking in a couple months. We'll see how it goes. Compressor is still set at 5% or 3 minutes an hour and maintaining 90 degrees and RH is 90 to 95%.
I would try to keep the RH% closer to 95% instead of 90. Also coating the slabs with a fungicide such as Premier will help to keep the mold growth down during slow kiln drying.
Quote from: scsmith42 on February 09, 2021, 07:30:11 AM
I would try to keep the RH% closer to 95% instead of 90. Also coating the slabs with a fungicide such as Premier will help to keep the mold growth down during slow kiln drying.
Thank you for your advice. If I raise the temp in the kiln will the RH go up? I'm currently running the comp 5% or 3 minutes an hour. Should I lower that setting also?
I installed a new temp/RH monitor today so I'm satisfied that my info is more accurate now. This afternoon temp was 91 and RH was 91. Nyle controller was reading 95 degrees. Sensor is in different location than new. New sensors are directly in front of air filter. I'll get the fungicide and use it.
Thanks again.
I would not suggest raising the temp. To do so would increase the drying rate. The key to successful drying of thick material is a lot of patience, and a lot of RH% for the first several weeks of drying.
Quote from: scsmith42 on February 09, 2021, 07:04:59 PM
I would not suggest raising the temp. To do so would increase the drying rate. The key to successful drying of thick material is a lot of patience, and a lot of RH% for the first several weeks of drying.
I really appreciate your time and advice. The wood's owner still wants to proceed in the kiln. I will turn temp down to 85 and have already cut compressor back to 3%. He's not willing to buy the Premier fungicide. Is there maybe a cheaper alternative?
Quote from: KenMac on February 10, 2021, 09:37:27 PM
Quote from: scsmith42 on February 09, 2021, 07:04:59 PM
I would not suggest raising the temp. To do so would increase the drying rate. The key to successful drying of thick material is a lot of patience, and a lot of RH% for the first several weeks of drying.
I really appreciate your time and advice. The wood's owner still wants to proceed in the kiln. I will turn temp down to 85 and have already cut compressor back to 3%. He's not willing to buy the Premier fungicide. Is there maybe a cheaper alternative?
Re Premier, not that I'm aware of.
If customer is unwilling to pay for fungicide I'm curious what you are charging for kiln drying for a few of months? How many Bf is in the kiln? Are you charging by the BF of by the amount of time? I wish you all the best but I don't see this ending well.
Quote from: customsawyer on February 13, 2021, 09:43:54 AM
If customer is unwilling to pay for fungicide I'm curious what you are charging for kiln drying for a few of months? How many Bf is in the kiln? Are you charging by the BF of by the amount of time? I wish you all the best but I don't see this ending well.
I guess it's hard for anyone to understand why I'm doing this and I get that. My kiln has sat idle for several years waiting until I got a mill to put it back to use. That plan hasn't panned out either since the only customers interested in drying lumber only had a few board feet. I currently have no place to store dried lumber, so I haven't sawn lumber to stock. This opportunity (or travesty) came along and it just felt right to do. Maybe it's Divinely inspired, or not, but it just seems like something I need to do for the owner. We will both learn a lot and hopefully he will get enough usable wood to build what his wife wants from this majestic tree from her family's homestead. (Her description).
My sawmill operation does not have to provide a living for me. I'm certainly not rich but I've found that I can be happy with SSI. My mill does allow me to have the tools and goodies that I need (want).
The owner is going to pay all expenses related to drying his wood and we will settle up for my time at some point. This whole endeavour is an experiment I guess. Had I been more in the know I would have suggested air drying first, but after the kiln was loaded the owner wants to leave it as is and proceed as best we can. I know no one in his right mind would take on this project but I'm content with it. I've never been accused of being in my right mind, :) By the way there are 17 4x4x12's and 7 3" slabs 25" or so and 2 2" slabs about 18" wide, all 12' long. He said 1800 bf. I haven't tried to figure it up.
Besides, y'all need someone to criticise and ridicule. Maybe that's my biggest contribution to the Forum! I'm ok with that. :D I do appreciate everyone's interest and advice.
I was wondering if Clorox would damage the wood if used to kill mold? Any ideas on that?
Ken
Ken, based on your most recent post I think that I would reduce the kiln temp to 70f in order to further slow down the drying rate and also to retard the development of mold.
I'd probably keep the RH% above 90, ad make sure that I had no more than 200 FPM of air flow thru the stacks and 100 FPM would be better.
In a few months when the ambient temps outside start getting warmer, increase the kiln temp to 80 and a month or so later back up to 90.
Mold will be less of a problem in a few months after the wood has dried part way, and 70f will result is less mold development as well as a very slow drying rate at the present time, which is what you need.
Quote from: scsmith42 on February 14, 2021, 11:48:45 AM
Ken, based on your most recent post I think that I would reduce the kiln temp to 70f in order to further slow down the drying rate and also to retard the development of mold.
I'd probably keep the RH% above 90, ad make sure that I had no more than 200 FPM of air flow thru the stacks and 100 FPM would be better.
In a few months when the ambient temps outside start getting warmer, increase the kiln temp to 80 and a month or so later back up to 90.
Mold will be less of a problem in a few months after the wood has dried part way, and 70f will result is less mold development as well as a very slow drying rate at the present time, which is what you need.
Thanks for your advice once again. The controller on my kiln has a low setting of 80 degrees for the compressor to operate, but I can leave it off and just run the fans with a separate heat source as needed to maintain 70 degrees. The 4 heat lamps should easily do that. RH has been above 90% since first checked, so hopefully that won't be an issue. Thanks again for understanding and being willing to help.
As an update to my ongoing saga, I turned the compressor and heater off on the 15th I think it was. The temp then was 93 and rh was 91ish. Fans were left on as recommended. As of 3:00 pm today the temp is 73 and rh is 93%. The stack has shrunk about 1/4 inch with no visible splitting or degrade yet. Mold seems to be no worse.
To update my load of pecan:
After turning all heat sources off and leaving fans (2) running the temp came down to 76 after several days while RH has stayed above 90%. Now the temp is back up to 84 and RH is 91%. My Electrophysics moisture meter shows readings of 99% to about 86% but may well be inaccurate even though Electrophysics says it is accurate to 99%.
Wood shows no visible degrade at this time, but stack has lowered about 3/4". Previous mold is no worse. Thanks again to everyone who gave advice on best way to proceed.
Just to update my saga of pecan slabs in my kiln: I have monitored kiln temp and RH since January and as outside temp has risen so has kiln chamber temp. As of this morning temp was 96.8 and RH was 82.4. RH is consistently dropping .1 to .2% a day. The slabs and 4x4's show no sign of degrade at this point and stack has shrunken in height by over an inch. I do not know MC of wood at this point, but am going as slowly as possible. I'm thinking that soon I will turn compressor on for about 5% of the time and try to move the process along. I am going to try to get an MC but am uncertain if it will be realistic. My Electrophysics moisture meter claims to read up to 99%, but I doubt its' accuracy. We'll see how this goes. Thanks again for all of the advice and please keep it coming when you think I should do differently than my plan.
I would recommend a Delmhurst J2000 moisture meter. Need to know what your moisture is to be able to give the best advice.
Quote from: customsawyer on June 20, 2021, 11:43:02 AM
I would recommend a Delmhurst J2000 moisture meter. Need to know what your moisture is to be able to give the best advice.
I have the Delmhorst J2000 but it only reads to 36 or so percent I think. Even if the Electrophysics (which I bought from Nyle with the kiln) is inaccurate I thought it would possibly show a rate of decrease in MC. That was my thinking anyway. Thanks for your input.
Even though I figured I'd be wasting my time, this morning I checked the pecan slabs and 4x4's with the Delmhorst J2000 meter. To my surprise with the hammer pins driven in completely it showed the slabs to be in the 19% range and the 4x4's at 22.2 to 23.6%. There has been no heat or compressor running since the first week the kiln was loaded. I can see no cracking or degrade on any piece. Granted I can only check exposed areas but I never imagined MC would be this low. Temp is 97 and RH is 81.6%. I'm thinking I should let it ride as is for a while longer even though I'm tempted to run compressor at 5%. Anyone have a suggestion on what to do now? Thanks in advance for your input.
I would run the compressor some. Likely the core moisture is higher but you could ramp the drying up one notch.
Also check your moisture meter and make sure you have it set for insulated pins when using the hammer.
Quote from: customsawyer on June 26, 2021, 07:12:49 AM
Also check your moisture meter and make sure you have it set for insulated pins when using the hammer.
Thank you. I will check that and recheck Monday.
Well, I have determined that either I am not blessed with the Delmhorst smart gene or the J2000 is not intuitive or user friendly. To the best of my ability I set the meter for insulated pins and checked several slabs and 4x4's. MC ran from 22.3 to 23.6. I am still surprised at this but I guess it is true. My plan is to start compressor at 5% for a while and monitor unless you kiln guru's advise otherwise.
What part of the slabs are you sticking the meter? How deep are you driving the pins?
Quote from: customsawyer on June 30, 2021, 05:22:12 AM
What part of the slabs are you sticking the meter? How deep are you driving the pins?
I'm checking exposed areas on the surface obviously near the edges. Some are on the air inlet side and some on the outlet side. Pins are driven in as far as possible- to the connector. Thanks for responding. Checked a second time and readings were very similar with one slightly higher and the rest slightly lower- maybe 0.2 either way.
When drying slabs I like to have a couple of a places where a narrow slab is above a wider one. This lets me check closer to the core in the face of the slab. I find that the edges and ends dry faster than the core. Try to have your probes in heart wood as it will normally read higher than sap wood. Also be careful driving the pins in all the way. Your meter might be reading the surface moisture if the face is making contact with the lumber. I only go in about half the thickness of the slab.
Thanks Jake. I will alter my process and keep checking. Is the Relative Humidity reading reliable in telling MC at this point or is that only applicable after drying is pretty much complete?
It tells you the drying force on the outside of the slab, not what is inside.
Quote from: WDH on July 03, 2021, 10:57:25 AM
It tells you the drying force on the outside of the slab, not what is inside.
Thank you Mr. Hamsley. I'm slowly learning this stuff, but will probably never get proficient at drying or sawing. :-[
Doing is how we learn best.
Quote from: WDH on July 03, 2021, 05:48:51 PM
Doing is how we learn best.
And reading these post on FF
A fantastic resource to counter the School of Hard Knocks.
Quote from: Stephen1 on July 04, 2021, 06:01:00 PM
Quote from: WDH on July 03, 2021, 05:48:51 PM
Doing is how we learn best.
And reading these post on FF
This one of the main reasons for me posting this thread. There is some extraordinary wisdom here!
Quote from: WDH on July 05, 2021, 07:34:39 AMA fantastic resource to counter the School of Hard Knocks.
I'd like to know when I can get out of that school!! :D
Quote from: K-Guy on July 06, 2021, 08:36:40 AM
Quote from: WDH on July 05, 2021, 07:34:39 AMA fantastic resource to counter the School of Hard Knocks.
I'd like to know when I can get out of that school!! :D
I don't think they give diplomas or even have a graduation service! The knocks just get harder.
Update on pecan slabs: MC today ranged from 13.5 to 17.8 % still with no visible degrade. Kiln temp was 99.8 and RH was 74.5%. RH has been dropping about 0.5 to 1% per day for the last week or so. MC has dropped about 0.2 to 0.4% per day. I decided to turn compressor on at 5% and kiln temp at 105. I'll monitor and report back in a few days. This endeavor may actually turn out successfully after all and not take as long to complete as thought or feared. We'll see. Thanks again for all input and direction to get this far along.
Time for another update on my adventure drying thick pecan slabs and 4x4's: Moisture content as of yesterday morning ranged from 6.0 to 9.3% with no splits or visible degrade. Kiln temp was 123 degrees. I decided to start sterilization process and turned heat and heat lamps on with setpoint of 150 degrees. Setpoint was reached by noon. This morning temp was at 156 on Nyle controller and 150 on my Elitech monitor with RH at 28.3% in kiln. Since slabs are 3" thick and 4x4's are obviously thicker I plan to leave temp up like this until Saturday unless advised otherwise. I will check the load tomorrow for changes but I hope all is well.
Thanks again to all who have taken interest in this project and offered advice and support. :)
During the sterilization process keep the auto vents closed and try to control the temps by playing with the heat lamps.
Try to keep whatever hot moist air in the kiln to stay in the kiln. This will mostly stop drying the case and allow the core to equalize to the case. It will bring the moisture gradients closer.
Thanks YH. Will do and so far, so good. How long should I leave the kiln closed after turning the heat off after sterilization is complete to allow equalization of core and surface?
I'll typically turn everything off, including the fans, because they build up pressure and may evacuate more moisture which is not desired, and let things sit for 24 hours. Just flip the switches and walk away for a day. Just a nice, gradual cool down, and then probe again to check for case and core spread and also average MC. The 3.3 % spread you are seeing is pretty high, your average moisture may settle to 8% maybe 7%, which would put you in target. If the case to core values haven't tightened up, go through the reheat cycle with the vents closed again.
Differential moisture content causes wood movement as the values equalize, so it's best to try to get them in alignment now instead of after they have been planed or flattened.
Differential shell to core moisture content will also cause wood movement when processing, like when ripping a board into two pieces.
Quote from: YellowHammer on August 20, 2021, 10:59:06 PM
I'll typically turn everything off, including the fans, because they build up pressure and may evacuate more moisture which is not desired, and let things sit for 24 hours. Just flip the switches and walk away for a day. Just a nice, gradual cool down, and then probe again to check for case and core spread and also average MC. The 3.3 % spread you are seeing is pretty high, your average moisture may settle to 8% maybe 7%, which would put you in target. If the case to core values haven't tightened up, go through the reheat cycle with the vents closed again.
Differential moisture content causes wood movement as the values equalize, so it's best to try to get them in alignment now instead of after they have been planed or flattened.
Thanks again YH. The main difference in MC I spoke of was between the thinnest slab and the 4x4's. I will certainly follow your advice. I plan to turn kiln off Monday morning. That will be about 84 hours at 150 degrees. Surely the core of all pieces will have reached 133 for 24 hours.
I do plan to come visit your business at some point in the not-too-distant future.
Thanks to you also WDH. I am aware of case hardening and its' effects on lumber.
Well it's time to conclude this adventure that went much better than I was fearing. The customer picked up his pecan slabs and 4x4's last Saturday morning and was very pleased with the way it looked. Slabs at 26" wide showed little cupping and no cracking and smaller ones were even better. The 16 4x4's were not perfect but are plenty good enough for his purpose- posts for tables and beds. Total time in kiln was from !-18-21 to 9-11-21 and I never had to tax the equipment to achieve target temps and RH. Heat lamps did help getting to 150 for sterilization. I did overshoot target MC by about 1%, but I have learned how to prevent that in the future thanks to Yellowhammer and other very knowledgeable FF members who unselfishly assisted and advised throughout this adventure that I agreed to before I knew what I was getting into.
Thanks to all of you for your help and I hope other members have gained some knowledge from my experiment. 8)