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General Forestry => Drying and Processing => Topic started by: forrestM on May 24, 2021, 08:03:59 AM

Title: Yellow pine drying and sterilization
Post by: forrestM on May 24, 2021, 08:03:59 AM
hello,

I am getting close to cutting some yellow pine (Iím pretty sure itís loblolly)

Iím cutting it at 1Ē x 6Ē  and planning to finish to a 3/4Ē x ~5Ē flooring for my house. 

I am not yet ready to install, but need to cut the logs before they sit much longer, so I am planning to cut and stack directly into my Nile l200m. So I donít get any stain, I am going to dry them to 15% and then take them out of the kiln and let them sit out of the weather. My assumption is that once the wood is down to 15 percent risk of staining, etc should be eliminated if I keep it dry?  

Hopefully, in a few months, when I have finished closing in my house, I will put it back in the kiln to take it down to 8%, and sterilize and set the pitch at the same time by taking it up to 160 degrees for 24 hours. Then Iíll straighten it and deliver to my friend who will tounge and groove and plane it into my flooring. 

I wanted to get some clarification on the pitch setting and sterilization process...with some poplar I have dried, I took it to 15 percent and then turned off the kiln unit, but left the fans running. The next day I came back to unload it and it had gone down to 14 percent. Do I want to stop the compressor and start the sterilization before I get to 8% so that it doesnít continue to dry? Would you do that at like 12 or 13 percent?

Also, do I dry syp at dB 120 and wb 75 like poplar and other group one woods?

Iím in Virginia. 

Any advice is appreciated! 

Thanks,
Forrest

Title: Re: Yellow pine drying and sterilization
Post by: K-Guy on May 24, 2021, 08:11:22 AM

Hi Forrest
We recommend setting the dry bulb to 160į F , turning the compressor off and when the dry bulb reaches 160įF leaving it for 24 hours for 1" wood 48 hours for 2". If the wood is really sappy leave it longer to cook the pitch even more.
Title: Re: Yellow pine drying and sterilization
Post by: forrestM on May 24, 2021, 08:14:15 AM
Hey Stan, 

But you always do that once youíve reached final mc? And it doesnít typically cause the wood to over-dry beyond that? 
Title: Re: Yellow pine drying and sterilization
Post by: Southside on May 24, 2021, 08:23:46 AM
Can you just sticker it and put a few fans on the stacks? It will be at 15% very quickly this time of year that way. Likely faster than in the kiln. 
Title: Re: Yellow pine drying and sterilization
Post by: K-Guy on May 24, 2021, 09:31:56 AM
doesnít typically cause the wood to over-dry beyond that? 


No the compressor is off any drop in moisture content will be from equalization.
Title: Re: Yellow pine drying and sterilization
Post by: forrestM on May 25, 2021, 06:30:28 PM
Is dB 120 and wb 75 the appropriate schedule for 
Syp?

@k-guy

Thanks,
Forrest

Title: Re: Yellow pine drying and sterilization
Post by: WDH on May 25, 2021, 08:45:39 PM
That is what I run.
Title: Re: Yellow pine drying and sterilization
Post by: K-Guy on May 26, 2021, 08:25:42 AM

Yes it is.
Title: Re: Yellow pine drying and sterilization
Post by: scsmith42 on May 28, 2021, 04:41:27 AM
Be sure to reduce your load size if you dry SYP from green in an L200. Usually I only load 1K bd ft of green syp for maximum drying rate.

If you load too much, the compressor canít remove water fast enough and your lumber will severely mold during the first week or so of the kiln run.
Title: Re: Yellow pine drying and sterilization
Post by: forrestM on May 28, 2021, 04:08:50 PM
Thanks to everyone. 

Title: Re: Yellow pine drying and sterilization
Post by: forrestM on June 21, 2021, 06:36:39 PM
 
(https://forestryforum.com/gallery/albums/userpics/49978/B5263525-C449-4EB3-98E1-C9A927CE0C3E.jpeg?easyrotate_cache=1624314598)
 
(https://forestryforum.com/gallery/albums/userpics/49978/EB872D9C-3803-4D42-B23B-8A124214CBB5.jpeg?easyrotate_cache=1624314591)
 
(https://forestryforum.com/gallery/albums/userpics/49978/1105205D-95BB-44B9-8854-D0392529AE62.jpeg?easyrotate_cache=1624314591)
 Cut my blanks yesterday in the heat and humidity! Stickered directly in the kiln as I sawed, with some extra fans blowing across. I had some little patches of blue stain, and I am hoping a quick kiln zap down to 15 percent will stave it off. I read a lot of posts on how quick it can take over. It was a 12 hour day, and I didnít see the patches spread as I was loading, so thatís good. The wood has been in my Nile l200m for 16 hours, has reached 120 dB, and lost about 10 percent moisture already. Avg is between 40 and 50 percent. 

Ended up with close to 860 board feet of 1x6 blanks. Had one more log, but wanted to keep the load size low. Should be plenty for my 400 sq ft floor. 

Hoping the high heat and humidity in the kiln doesnít encourage the blue stain - from what Iíve read it should be ok, but I really want clear flooring!

Do you think I should sterilize now, even though I will be drying it down to final moisture in a couple months when Iím ready to install?

Also, for a house with wood heat, and minimal air conditioning, what should my final mc be for Virginia? My plan was to take it down to final mc, remove from the kiln, straighten to 5 1/2 inches, and take to my friend for tongue and groove and then install. 

It was my understanding hardwood floors need to be 7-8 percent, but syp doesnít want to be that dry?

Thanks, 
Forrest


Title: Re: Yellow pine drying and sterilization
Post by: Southside on June 21, 2021, 10:03:16 PM
You don't want your pine to be below 9 or it will give you problems when it comes time for the millwork. 

Also when the MC is that high the numbers you are seeing on the screen are not accurate. So 50 to 40 means things are going in the right direction, but don't take those values as gospel. Get to 28 and then you can be comfortable with the values. 

Where will you store the lumber for the next couple of months after it comes out of the kiln? 
Title: Re: Yellow pine drying and sterilization
Post by: K-Guy on June 22, 2021, 08:07:49 AM

Once you are at about 15% you have be done with most of the shrinkage, you could machine it then. When you are ready finish the drying to 7-8% and install.
Title: Re: Yellow pine drying and sterilization
Post by: scsmith42 on June 22, 2021, 08:30:03 AM



Do you think I should sterilize now, even though I will be drying it down to final moisture in a couple months when Iím ready to install?



Thanks,
Forrest
Do not sterilize until the lumber has reached close to it's final MC%.  In most species Sterilizing at too high of a MC% can cause honeycomb inside the lumber.
Title: Re: Yellow pine drying and sterilization
Post by: forrestM on June 22, 2021, 12:25:32 PM
I plan to keep it on stickers, in one of my drying sheds (concrete floor, roof, and open on all sides ) until I'm ready for it. 

is it often the case that people will dry to 15, machine, and then finish drying prior to installing? 

good tip about honeycomb risk when sterilizing at high moisture content.

a good final mc would be 10 percent with syp?

Title: Re: Yellow pine drying and sterilization
Post by: forrestM on June 22, 2021, 12:33:20 PM
would I be better off storing it indoors, dead stacked? 
Title: Re: Yellow pine drying and sterilization
Post by: btulloh on June 22, 2021, 12:47:44 PM
I would dry to the target mc before machining. Then store inside dead stacked. Then the recommended process for flooring is move it where it will be installed and let it adjust to that climate for a week, then install it.  

Just reinforcing what was mentioned earlier, i accidentally took a load of syp  down to 5-6 percent that i was using to make shiplap with a chamfer. I got it machined ok, but it was a bit crispy and less than wonderful to machine.  Usable, but less than ideal. I wonít be burning the cookies again after learning my lesson.
Title: Re: Yellow pine drying and sterilization
Post by: Southside on June 22, 2021, 03:04:39 PM
is it often the case that people will dry to 15, machine, and then finish drying prior to installing? 


That's not a recommended plan.  You will be surprised at how much movement you will experience between 15% and 9%-10%.  I straight lined a load one time of reclaimed lumber, then finished and heat treated, it in the kiln.  This stuff was ancient and had been at EMC for decades.  Unloading the kiln it was clear to me that I had screwed up. it was an absolute nightmare to run through the moulder.  
Title: Re: Yellow pine drying and sterilization
Post by: YellowHammer on June 22, 2021, 04:28:17 PM
I would dry to the target mc before machining. Then store inside dead stacked.

I wonít be burning the cookies again after learning my lesson.
I agree.  It would be like putting the icing on the cake before putting the cake in the oven. Bad things happen.
Yep, once the cookies are burned, they are burned.   
Title: Re: Yellow pine drying and sterilization
Post by: GeneWengert-WoodDoc on June 23, 2021, 11:39:27 PM
I am curious why someone would want to sterilize syp.  What insect is likely to cause damage when at 9% MC?
Title: Re: Yellow pine drying and sterilization
Post by: Southside on June 23, 2021, 11:55:40 PM
More of a setting the pitch. 
Title: Re: Yellow pine drying and sterilization
Post by: GeneWengert-WoodDoc on June 24, 2021, 09:06:43 AM
Indeed, syp is a bit different than most other softwood species.  It shrinks a bit more when the MC changes, but more importantly, it warps when the MC changes.  This warp is due to the grain in the tree, especially the grain angles for the first 15 to 20 years.  Therefore, in addition to perfect stacking when drying, it is also very important to get as close to the final MC as possible. At the same time, drying under about 10% to 12% MC greatly increases machining defects, as the woods getting so much stronger and the grain angle factor too.  Planers, molders, routers, etc. need to be fairly powerful as the MC drops and strength increases.  The bottom line is that it is rare to find syp used for many wood products except structural pieces.

Regarding setting the pitch, for those folks not familiar with the process, the pitch or sap in syp is plentiful.  It consists of many different chemicals.   Some of these chemicals are fairly liquid and runny at room temperature.  Some are liquid at runny at cooler temperatures too. And some become liquid and runny at warmer temperatures.  This pitch can also migrate through paint and even plastic overlays.  The pitch interferes with gluing and also clogs up sandpaper.  It can coat saws and knives.  In the kiln, it can coat the walls.  When syp is used for firewood, the pitch can coat chimneys and create creosote as well, which in both cases is creating a fire hazard.  So, dusting drying, what we do is heat the wood to at least 160 F (180 F is even better and faster) which will evaporate the chemicals in,pitch that are liquid and runny at 100 F and maybe a bit hotter.  After 24 hours at 180 F and around 48 hours at 160 F for lumber under 2Ē actual thickness, the pitch or sap that remains in the wood will be hard at room temperature.  This process of evaporation is called "setting the pitch."  Should the Wood be subsequently heated in processing (such as heat from machining or sanding, or in a finishing oven), the heat can soften the remaining pitch and create issues when softened.  Of course, when cooled, the pitch hardens.a. Due to this softening, which can happen in a home when the wood is, for example, near a fireplace or indirect sunlight or has a hot pan on it, etc., we generally prefer 180 F treatment temperature "just in case,". Certainly 160 F is adequate. OST of the time.
Title: Re: Yellow pine drying and sterilization
Post by: cabindoc on June 29, 2021, 05:47:36 AM
Subscribing
Title: Re: Yellow pine drying and sterilization
Post by: doc henderson on June 29, 2021, 10:31:59 AM
good to hear from you Gene.  
Title: Re: Yellow pine drying and sterilization
Post by: forrestM on September 02, 2021, 12:12:40 PM
@GeneWengert-WoodDoc (https://forestryforum.com/board/index.php?action=profile;u=20498) 

With syp you donít need to worry about killing bugs? Is that true for ewp as well?

Thanks,
Forrest
Title: Re: Yellow pine drying and sterilization
Post by: Larry on September 02, 2021, 07:21:33 PM
Also, for a house with wood heat, and minimal air conditioning, what should my final mc be for Virginia? My plan was to take it down to final mc, remove from the kiln, straighten to 5 1/2 inches, and take to my friend for tongue and groove and then install.

If your heating with a woodstove 24/7 I would be concerned about the significant cracks that will develop in 5 1/2" wide strips.  With minimal AC I can see the MC going from 9+ summer to 6 late winter.
Title: Re: Yellow pine drying and sterilization
Post by: GeneWengert-WoodDoc on September 04, 2021, 09:16:08 AM
There is basically only one insect that gets into DRY pineÖthe old house borerÖand it does not cause extensive damage and seldom is able to reproduce.  All other insects need wetter wood.  This is for the US and Canada.  Of course, we get the carpenter bees, but sterilization is not a solutionÖsame with termites.

Now, if we have ambrosia beetles and the wood is used in a wetter location, even with sterilization, insects can be expected.  This is why we use pressure treatment in wet locations and for ground contact.  Borates can be used when water will not leach out the chemical.  Getting borate deep into the wood can be an issue.in other words, borate treatment is often a multi day procedure.  Plus retrying after treatment may be necessary.

Bottom line is that sterilization for softwoods is not effective for protection of the wood used in wet locations.  Chemical methods, usually PROPER pressure treatment, will provide thirty years of protection or more.
Title: Re: Yellow pine drying and sterilization
Post by: YellowHammer on September 04, 2021, 10:30:48 AM
I use heat as a means to routinely kill anything that has taken up homesteading in my air dried wood stacks and pallets. 

As Gene mentions, carpenter bees are very bad here until late summer, and they will bore into anything they can, even old pressure treated wood.  I have 8 traps hanging around my barn and they fill up. 

The bottom of my kiln is littered with all kinds of after air drying creepy crawlies, and includes hundreds of carpenter bees hidden in the wood and pallets, scorpions, mud dobbers, wasps of several species, hornets, black widows, mice, snakes, etc.

There is nothing worse than unstacking a pile of air dried stickered wood and having a scorpion crawl out and land on your foot, or bunch of hornets come boiling out at you.  So I heat sterilize everything, not matter what is is, take it out of the kiln, dead stack it immediately, and put it in stasis in the main building.

Setting the pitch in pine serves the same purpose.  It also simplifies the questions I get asked all the time from "green minded" customers.

Question #1:  "Is it kiln dried?"  Me: "Yes"
Question #2:  "Have any chemicals of any kind touched the wood? Has it been sprayed or treated?"    Me: "No"
Question #3:  "Has is been sterilized?  Is everything dead in it?"    Me: "Yes"
Question #4:  "How much does it cost?"  Me: "Not too much, let's load you up." :D     
Title: Re: Yellow pine drying and sterilization
Post by: WDH on September 04, 2021, 10:54:11 AM
  "How much does it cost?"  Me: "Not too much, let's load you up." :D    
Surely you donít expect me to believe that.  
Title: Re: Yellow pine drying and sterilization
Post by: YellowHammer on September 04, 2021, 09:45:48 PM

 "How much does it cost?"  Me: "Not too much, let's load you up." :D    
Surely you donít expect me to believe that.  


No, but all I need is for THEM to believe it!! :D :D :D :D
Title: Re: Yellow pine drying and sterilization
Post by: customsawyer on September 05, 2021, 07:56:48 AM
I'm not "buying" that either.
Title: Re: Yellow pine drying and sterilization
Post by: forrestM on September 12, 2021, 09:40:08 AM
@GeneWengert-WoodDoc (https://forestryforum.com/board/index.php?action=profile;u=20498) 

Just to clarify, sterilization will kill active insects - including termites. It just isnít necessary for dry pine, and wonít prevent further infestation from the pine borer you mentioned, termites in wet locations, or carpenter bees. 

Thanks!
Title: Re: Yellow pine drying and sterilization
Post by: Crossroads on September 19, 2021, 12:54:59 AM
Sorry I canít add anything to this topic, but I sure appreciate the information being shared.