Air Drying vs Kiln Drying

[Jazzflooringco]

Hi I am new to the forum. I thought I would start by opening a new topic with one of my questions of many. I am in the process of milling a 60" bur oak into lumber and then into flooring. We are taking it to a guy in my area to have it dried. He told me that he would be able to put it right into the kiln. I was under the impression that wood should air dry for a certain amount of time before going into the kiln. What are your thoughts on this? Should I be concerned the guy I hired is going to dry my lumber too fast? Thanks in advance!

Also if there are any unwritten rules of the forum that I may not know about feel free to text me @ 262-385-1250. Don't want to step on any toes here...

[Ljohnsaw]

First thing is to update your profile so we know where you are. What thickness are you going to mill the wood? Inch and an eighth? Inch? Seven eighths? Three quarters? The thinner the faster it will dry. I milled some 1" cedar and it lost more than half the moisture in a week. If you are in a dry area, a month of air drying I'll shorten the kiln time.

Drying experts will be a long shortly. There are some oaks that behave well, others that are a pain. I know you don't want to dry ok too fast.

[doc henderson]

Welcome!  the rules are written, but it takes a while to figure it all out.  A few folks never figure it out.  Members here will let you know.  the big stuff, it is a family-oriented forum, not a macho roughneck one, so any foul language will auto correct, or you will be admonished by computer.  If you want to sell or advertise something, you have to read those rules and essentially there should be a donation by % to the forum, state in the text you have read and understand them. 

There are at least two issues.  You must have some knowledge as you asking a good question.  filling in your profile or giving some history about your background will help us temper our answers to your knowledge level.  Oak in general needs to dry slow.  air drying would need to be controlled with medium airflow and no direct sunlight and covered to keep rain off.  air drying can be harder to control, but cheap if you have the area.  Kiln drying is easier to control (the whole point of a kiln) and if your kiln guy is good, he will follow a schedule.  How will you be charged.  Is he busy?  If he goes slow per the schedule and charges by the board foot, all is good.  If he then speeds it up to clear the kiln, then he may damage your load.  if he charges by the day, you may get a big bill at the end. 

A combo of initial air drying then finish in the kiln may make sense.  Much irreversible damage is done early, so if you are airdrying oak, you need to know what you are doing.  A busy kiln might provide air drying initially, and then they need to know what they are doing.  Are you and the kiln operator professionals, or hobby guys?  what is the wood for and for whom?  Your handle implies you are a professional flooring guy?  others will chime in soon.  @YellowHammer @Southside

[scsmith42]

A 60" burr oak would be a great candidate for quartersawing.  You'll lose some yield, but end up with a much more valuable (and stable) floor board.

Presuming that you're milling at 1-1/8" green to make a 3/4" dry flooring board, there is no reason why you can't go into a kiln green with your lumber.  A DH kiln will take around 4 weeks to dry green 4/4 oak down to 8%MC.

A lot of the "internet wisdom" about having to air dry first is a bunch of bunk.  It all comes down to using the proper kiln and kiln schedule.  Yes, very thick woods of certain species are better air dried first, but not a 1" board for flooring.

[Jazzflooringco]

Thanks for the info guys. We are rift and quartersawing it. Super excited. Stopped by the saw mill operator the other day and it's some of the coolest looking wood I have seen.  Drying it down from 1 1/8". Only concern I have right now is I just hope it doesn't crook.

[beenthere]

Could very well crook, as a result of the growth stresses laid down in the tree as outer rings are added each year. 
Just means after drying, that the boards need straightening (jointing) an edge (which is normal before running through a moulder regardless). 

[YellowHammer]

It will most definitely crook, if it is true riff or quartersawn wood, as these techniques will put the stress intentionally in the crook or edge direction (shear plane) vs the face or bow direction. So if done correctly, quartersawn boards will dry very flat with some crooked edges that you can remove later during secondary processing with an edger, SLR, or some multi head moulders. 

Any wood can be kiln dried from green off the mill as long as the proper schedule is followed to never exceed the max allowable moisture removal rate as well as the temperature profile to not cause enzyme stain, or other issues.  However, drying from green is fraught with danger as many serious drying defects occur in the initial stages of drying. So the question is what are the credentials of the kiln operator?  What drying schedule is he following?  What kind of kiln does he have and how long has he been doing it?  There is a very narrow error band between high quality kiln dried wood and cracked garbage kiln ruined wood. 

[jimF]

As mentioned, the green state of the wood in a drying condition, sun exposure, breeze, is when most damage is done, ie. on the green chain. For oak, surface checks are easy to start, can never heal or cure it once it starts. As also mentioned, air drying has almost no control and kiln drying is a method that is able to have the most control.

On the green chain stack under a roof and block any breeze. During air drying cover with a roof to protect from rain and sun. Use of "shade-dry" can be used to reduce air flow through the stack. If the wood smells like vinegar it is bacterially infected and is more prone to surface checks.

It is possible to cause staining in oak but not the biggest concern; just keep an eye on it and if mold develops increase air flow..

[Ianab]

The reason for air drying first is to reduce the time that the kiln is tied up. You can of course dry from green in a kiln, but you have to set the schedule to one that's safe for thew wood type. As mentioned above, white oak might take a month in the kiln, and you have to operate and charge for the kiln time by the day. Now if you can get some air drying in first, that cuts down the kiln time. So maybe air dry for 6 months, then it only needs a week of kiln time to finish. Now you are able to get a lot more wood though your kiln each month. 

Down sides are that air drying isn't well controlled, it's possible to mess up some species by drying too fast (or too slow). Other one is that you now have to wait 6 months to be able to use or sell the wood, and that has an economic cost involved. 

So the best method depends on "things".  

You can ruin wood by poor air drying or poor kiln drying. Try and up the drying settings to get that oak dry in 3 weeks, probably ruin it. Set it out to air dry in the middle of Summer in a dry climate, same. problem. 

[customsawyer]

I would be a little cautious of a kiln operator willing to take green oak strait to their kiln. It can be done but ties up the kiln longer.

[scsmith42]

Thanks for the info guys. We are rift and quartersawing it. Super excited. Stopped by the saw mill operator the other day and it's some of the coolest looking wood I have seen.  Drying it down from 1 1/8". Only concern I have right now is I just hope it doesn't crook.

You can reduce the amount of crook by minimizing the amount of juvenile (pith) wood along one side of the board, and minimizing the amount of sapwood along the other side.

For the best figure, use Yellowhammer's "Reverse Roll" quartersawing method.  It will yield 75% or greater high fleck boards.  You can read up on it on this forum and on Yellowhammer's Facebook page.

For the best compromise between milling speed and amount of high figure, use the "Woodmizer" method of pulling 3 or so boards from the middle of the log, and then putting the remaining 1/3 log sections face to face stood up ont he mill and mill down.  This will yield around 50% high fleck, and 50% low fleck / rift.

Removing slab offcuts to turn the log into an octagon before milling will help reduce the crook related to sapwood.

[jimF]

This the first time I've seen anything concerning reverse roll.  I put that in the search engine and just get articles referring to it. Does anyone have a link to the description?

[doc henderson]

It was done at a sawing project, and I think 123maxbars has a you tube of the event.  It is the second half of the video.

https://www.youtube.com/watch?v=zNwzXUzHhMk&t=106s


here is one thread.

Reverse Roll Quarter Sawing - Page 4 (forestryforum.com)

[longtime lurker]

I'm going to be a bit of a heretic here and say kiln drying is way overrated unless you own a sawmill.

Anything made of wood pre mid 1800's - and that's less than 200 years ago - never saw the inside of a kiln. Now the argument goes that pre air conditioning and central heating wood never needed to get below EMC kind of overlooks the inconvenient fact that people actually keep  Louis XIV furniture or great grandma's rocker inside their 200 year old house- that's been updated to include all the mod cons - with little thought that apparently it should all collapse around their ears. Wood moves with moisture shifts and the two greatest factors to long service life are wood quality and quality of workmanship, not moisture content at manufacture.

Kilns used to be the preserve of big mills due to cost of installation and the big mills pushed KD as an ours are better than yours thing for a century. Lower capital cost equipment  changed that after WW2, and the building and manufacturing industries were quick to take advantage of the initial working stability of KD lumber to go to faster and easier so cheaper jointing and fastening methods. If KD was so much superior you should expect a chair from Ikea to outlast great grandma's aforementioned rocker and we all know how that will turn out. I know of one great grandma's rocker built by great grandpa in West Texas that's been around the world in every thing from desert to tropical jungle and back to Texas and is still in service. Great grandpa didn't have a kiln, he just knew how to build things to last.

Nope, KD lumber is a rort, and the only real beneficiaries of it are sawmillers because what a.kiln really does is not improve lumber quality so much as it improves the sawmillers cash flow cycle, and that's why I need more kilns, cuz I can't wait for lumber to air dry to get paid.

[Magicman]

This is framing lumber and not actually related to the topic subject, but it may interest someone about sticker drying framing lumber:

In the 1950's, I remember seeing lumber stacked at sawmills in a sorta stepladder arrangement, crisscrossed at the tops.  The lumber for the home that I grew up in was stacked that way and I remember watching my Granddad flipping it end over end.

I stopped counting several years ago when my number of "whole house" framing lumber jobs reached 25, and I am quite sure that it is easily double that now.  The lumber is stickered, never kiln dried, and used whenever the building need arises.  I seldom get to see it after sawing but I do have a few pictures:






Store bought framing lumber has been dried to 18% and stickered SYP lumber will easily dry to below 20% within a couple of months.

[scsmith42]

I'm going to be a bit of a heretic here and say kiln drying is way overrated unless you own a sawmill.

Anything made of wood pre mid 1800's - and that's less than 200 years ago - never saw the inside of a kiln. Now the argument goes that pre air conditioning and central heating wood never needed to get below EMC kind of overlooks the inconvenient fact that people actually keep  Louis XIV furniture or great grandma's rocker inside their 200 year old house- that's been updated to include all the mod cons - with little thought that apparently it should all collapse around their ears. Wood moves with moisture shifts and the two greatest factors to long service life are wood quality and quality of workmanship, not moisture content at manufacture.

Kilns used to be the preserve of big mills due to cost of installation and the big mills pushed KD as an ours are better than yours thing for a century. Lower capital cost equipment  changed that after WW2, and the building and manufacturing industries were quick to take advantage of the initial working stability of KD lumber to go to faster and easier so cheaper jointing and fastening methods. If KD was so much superior you should expect a chair from Ikea to outlast great grandma's aforementioned rocker and we all know how that will turn out. I know of one great grandma's rocker built by great grandpa in West Texas that's been around the world in every thing from desert to tropical jungle and back to Texas and is still in service. Great grandpa didn't have a kiln, he just knew how to build things to last.

Nope, KD lumber is a rort, and the only real beneficiaries of it are sawmillers because what a.kiln really does is not improve lumber quality so much as it improves the sawmillers cash flow cycle, and that's why I need more kilns, cuz I can't wait for lumber to air dry to get paid.

LL, I think that the benefits of kiln drying will vary depending upon where in the world / country that your lumber is sourced.

My my area (NC USA), we have a lot of lyctid powder post beetles that will inhabit milled lumber.  The sterilization cycle performed at the end of the drying process will kill the beetles, their eggs and larvae, preventing an infestation from occurring after the flooring is installed.  If for no other reason, kiln drying is highly advised for lumber produced in my area that is destined for indoor use.

[Stephen1]

KD is beneficial north of you here in the land of freezing and boiling. Our houses moisture swing so much. LL our 200 YO old furniture is not that great. 

[Magicman]

our 200 YO old furniture is not that great

But it has character and it's home. 

[Larry]

During the winter, I heat my shop 24/7 with a wood stove. The shop is toasty warm with very low humidity due to the wood heat. If I bring air dried wood into the shop in the early fall within a few months the MC will drop to the same MC as wood fresh out of my kiln. The wood will remain at this level until late spring (actually I air condition so once dry wood stays fairly dry).

I suspect the woodworkers 200 years ago did most cabinet work in the winter using low MC wood from wood heat in the shop. During the warm season they probably were out logging, running the sawmill, or farming. Not much got made during this time.

I have no idea, but I'm guessing most of the furniture built 200 years ago is gone due to poor construction, misuse, or even barroom brawls. Only the high end stuff has survived and we don't know how many times some of that has been rebuilt.

[doc henderson]

or it was an expensive piece, and no one was allowed to set on it for 5 generations.  

[longtime lurker]

LL, I think that the benefits of kiln drying will vary depending upon where in the world / country that your lumber is sourced.

My my area (NC USA), we have a lot of lyctid powder post beetles that will inhabit milled lumber.  The sterilization cycle performed at the end of the drying process will kill the beetles, their eggs and larvae, preventing an infestation from occurring after the flooring is installed.  If for no other reason, kiln drying is highly advised for lumber produced in my area that is destined for indoor use.

I don't disagree with that Scott but the same argument applies... there are plenty of items about that pre date the common use of KD lumber and the borers haven't eaten them yet.
And you know as well as I that heat sterilization will kill borers but should the material get wet again borer re-infestation can occur. I also know that you guys now have far more restrictions around the use of chemical barriers to insect pests than we do here.  Was it always that way in NC or was the use of borates, oil or pitch or some other preventative common there 100 years ago? Lead based paint would be pretty effective too I'd imagine.

I'm not saying kiln drying isn't a good thing or that its sometimes not the best thing, so much as that there are more than one ways to skin this particular cat.  As a processor the main benefit of a kiln I see is the accelerated cash flow cycle through not having to wait a year an inch for wood to dry, every other benifit of kiln drying has an alternate historically proven solution.

[Peter Drouin]

Bring a  M meter to a big box store and check the lumber, you might be surprised. I do air dry some before it goes in the Kiln.

[doc henderson]

I am not sure the lead in paint kills borers, but they tend to have a heck of a time with math.  

[Ianab]

When you look at (surviving) old furniture you will see it's been built with wood movement in mind. The stuff that wasn't has fallen apart years ago. 

Here in NZ it's often humid, but houses aren't climate controlled. We have basic heating and usually AC now, but it's only intermittent use. Generally you open a window if you want cooler, unless it's the middle of Summer and hot outside, then we now have a heat pump / AC. But average humidity year round is in the 60-100% range. Met Service says humidity is 88%, and temp is 17C. Couple of degrees warmer in the house, but not by much. So building with wood dried to US standards could actually be a problem, it's going to suck moisture from the air, and expand. Some companies import KD flooring (oak etc) from the US, but before it can be used reliably they have to unpack and sticker it, to GAIN moisture before the floor is laid. Putting down 6% wood in a 12% house is even worse that the reverse. 

The comment about killing bugs is valid, if you have air dried wood it's possible for borer to get into many species, and then hatch out later in someones dining table. NOT a good look. But kiln drying doesn't prevent re-infestation later on. What generally protects furniture is a film finish. Be that varnish / shellac / paint / wax etc. The female beetle is wandering around looking for a place to lay eggs, and the trigger is tasting cellulose, that means it's wood, and a good place to lay eggs. If all she tastes is polyurethane (or anything that's not wood), no point laying an egg there. But when selling wood that's susceptible to borer, having the peace of mind that "there are no live bugs in there" is a good thing. So again, that old furniture either had some finish (shellac / wax / curing oils) or was a species of wood that naturally resists borer attacks. 

[jimF]

Shops here in the US 200 years ago were not sealed as tight as what we have now. In the winter, at least in the south, is very damp, 15-18 % EMC, if there is no modern insulation and house wrap on the house

[YellowHammer]

Here in Alabama, other business not selling kiln dried and sterilized wood are courting disaster and financial ruin. 

I get at least one call a week from some person or another who either bought wood or built a piece of furniture from wood that was either knowingly or unknowingly built with non kiln dried and sterilized lumber.

I call the pieces of furniture "dog leg" furniture because the usual customer complaint is that the table or chair has warped or twisted to the point it will "lift its leg" off the floor like a dog peeing.  I call the not sterilized furniture or flooring with bugs actively coming out of it a "nest."

The very upset "not my customer" gets even more upset when they ask me what I can do, and if I can sterilize their furniture in my kilns, bought from one of my competitors, and I simply tell them "Nope, if you want it solved, get your money back from them or call a lawyer.  I'm not getting on the middle of their mess."

As far a bug remediation, the problem balloons exponentially, very quickly.  If it's to the point where the bugs are coming out of the integral hardwood pieces of the house, which is often when the homeowner or wife of the homeowner notices the problem, usually powder post beetles, such as the flooring or timber or beams, then it becomes a real nightmare, and an insurance claim to replace the damaged or infested wood, no different than a termite infestation.  One of the local professional bug exterminators tells me about it routinely, he says although spraying with surface treatments with boron derivatives is effective to some extent, many home owners and insurance companies will not approve reconstruction of the damaged parts of the house until a "certified and licensed" exterminator has certified the house as 100% bug free, and the guy I know says the only way he personally will 100% certify a house is by tenting and fumigating, and that starts at $20K per house.  Only then will the insurance company, many times, and even the homeowner, agree to re inhabit the house.  Of course, the repair and reconstruction also costs money.  This may seem like overkill, but in a half million to million dollar house, who would buy one not certified bug free?  What bank would carry a loan on one?  None.  Most people could not care less if the bugs coming out of their wood are termites, powder post beetles, worms or even ants.  Yellowhammerism "Bugs is bugs and bugs is bad."

Obviously, then, the very first thing the homeowner's insurance company will do is look for the supplier or producer of the offending furniture and lumber and sue them for the money, which generally puts them out of business, or permanently ruins their reputation, if they have one. 

These are not isolated cases, but relatively common.

This is further proliferated by shady bug exterminators who have learned to feed off the clients worries and even point out holes in reclaimed but sterilized lumber in furniture, and tell them the wood is obviously infected, when it's not, and tell the customer that they need to pay to "take care of it."  Total criminal shakedown.  That's why we don't even sell reclaimed lumber any more, we tried for a short time, but I got tired of explaining that our wood was sterilized and got tired of customers telling horror stories of buying other's reclaimed and infested not sterilized wood and seeing bugs emerging out of their table while eating a pizza or out of a headboard and getting into their wife's hair.  It's also why we keep detailed sterilization and kiln drying records.

I can only speak for my area, in North Alabama and Southern Tennessee, but this is a real and constant problem, to such an extent that our insurance company requires us to pay for "End Users" and "Pests and Mold" additions to our business policy.

I am not insulting or dogging any on this Forum who does not kiln dry and sterilize, you guys know what you are doing and are informed and know your wood species and locales.  I just am saying this is my personal experience in my locale.   

[scsmith42]

LL, I think that the benefits of kiln drying will vary depending upon where in the world / country that your lumber is sourced.

My my area (NC USA), we have a lot of lyctid powder post beetles that will inhabit milled lumber.  The sterilization cycle performed at the end of the drying process will kill the beetles, their eggs and larvae, preventing an infestation from occurring after the flooring is installed.  If for no other reason, kiln drying is highly advised for lumber produced in my area that is destined for indoor use.

I don't disagree with that Scott but the same argument applies... there are plenty of items about that pre date the common use of KD lumber and the borers haven't eaten them yet.
And you know as well as I that heat sterilization will kill borers but should the material get wet again borer re-infestation can occur. I also know that you guys now have far more restrictions around the use of chemical barriers to insect pests than we do here.  Was it always that way in NC or was the use of borates, oil or pitch or some other preventative common there 100 years ago? Lead based paint would be pretty effective too I'd imagine.

I'm not saying kiln drying isn't a good thing or that its sometimes not the best thing, so much as that there are more than one ways to skin this particular cat.  As a processor the main benefit of a kiln I see is the accelerated cash flow cycle through not having to wait a year an inch for wood to dry, every other benifit of kiln drying has an alternate historically proven solution.

I don't disagree with you at all (and even have several old pieces of furniture in my own home that were built from air dried material).

As usual, Robert has very eloquently explained the logic in our part of the world for focusing primarily on selling kiln dried lumber.  And for us it's also a marketing point to help differentiate us from the competition.

Bugs were not as much of a problem in other parts of the US where I have lived, but they sure are here in the SE portion of the country.

[customsawyer]

Correct me if I'm wrong but didn't the WoodDoc (Gene) say one time that the PPB couldn't or wouldn't bore into planed lumber?

[Don P]

But only on the 12th of January.

It will sure get into unfinished flooring sitting in a contaminated warehouse only to emerge later under the dining room table in the clients new house. I've also had it emerge from painted trim. Again I suspect that came from bad storage after KD and milling.

I've seen bugs do things extension say they don't do. We have pppb's, problem powderpost beetles, bad ash bostrichids, troubled turpentine beetles and non anorexic anobiids. We've heat treated wood for other contractors as well. I much prefer to give them the boot just before the wood heads for the job to be finished.

[caveman]

Jake, I do remember WoodDoc saying that about planed lumber and I was thinking about it while reading this thread.  

I don't intend to derail this discussion about kiln drying, but how often do y'all spray insecticide in your inside wood storage areas?  Come to think of it, we need to do this again.  Last time we used Talstar.  

[customsawyer]

My store is sprayed on a quarterly schedule by a bug company. With my volume of sales, I want there to be records that it is all being done. 

[Don P]

What are you spraying for, what is landing on the wood and are the customers warned about that if the lumber is sprayed? There's a slippery slope either way  .

[caveman]

DonP, I assume your question is for CustomSawyer, but we don't spray the wood in the shop, which is also our storage/sale area.  We do spray the floor and around the perimeter of the shop like I do when I spray my house to keep the bugs out and kill the ones that trespass. Jake's volume of sales far exceeds ours, but we try to do a good job with what we do-we are still splashing around in the shallow end of the pool.

We do treat hardwoods as they go onto stickers with DOT.  If there is any doubt, we run them through the hot box too after the solar kiln cycle.  Our polyethylene has faded on the solar kiln and it does not get as hot as it did when new.  Today, when I got off work, I checked it and it was 120* inside, about 30* over air temp.  When it had a clear top, it would routinely get 50-60* over air temp in the kiln.  We are reluctant to change anything since it does such a good job drying wood.  

[Don P]

It was for either/anyone, I was just curious what and why you were spraying. You're going after what I call pests vs the wood bugs. I should knock back some of my pests but I just use DOT on the wood. I've toyed with trying to get the barn/shop up to 150. I built it before I knew to borate my hardwoods so it is a source of contamination of the lumber... and I really don't want to burn it  .

[Machinebuilder]

What is DOT?

[taylorsmissbeehaven]

I have the same question. This is a new area for me and I am very curious as to what is needed and how to disclose all the info to a customer without alarming them. Im learning that many people have no idea about these problems and dont understand/want any chemicals on the wood they are buying for their next indoor project. Seems to be a bit of a catch 22 leaving the sawing with the short straw. Any advice would be much appreciated!!
Caveman, what style solar kiln are you using, VA tech plans? Im working on that as well. Lots to learn....

[YellowHammer]

Disodium Octagoratr Tetrahyrate (Timbor or Boracare or simialr)

[taylorsmissbeehaven]

Thanks Y.H. Timbor is what I am using. I understand and appreciate the push for organic but a house full of bugs is a problem as well!!! I like to know and understand what Im doing so I can explain it in a concise manner that doesnt scare people but helps them understand as well. Sometimes that can be a challenge.

[YellowHammer]

Remember, I am not the kiln drying police, and I am not telling people what to do or not to do, just my personal experiences on the subject.   Any of the pesticide treatments that I am aware of are surface treatments only, and they must be applied in such a way to create an uninterrupted surface layer much like a termite bond in the soil.  Penetration in heartwood of hardwood is very limited, but better in softwoods like pine.  It must be applied in a 1:1 concentrate for active maximum penetration.  That being said, again, in conversations with my bug guy, he says Boracare is the only pesticide approved in the state of Alabama for treatment of log homes, but I have not checked up on that.  Of course, using it on food bearing surfaces is in violation of the label.  It is toxic to fish and animals, I assume because it contains glycol.     

I used these in the past, however, they do not come without customer "issues" if you are selling wood as a business.

They are not foolproof unless applied correctly (seen that), do not kill the insects living in the wood which really grosses customers out ("Oh, sure the bugs are still alive but they will die when they come out and fly around your house for a while"), and should be disclosed to the customer that they are being applied (WHAT! You are spraying the wood I may use for my counter for cutting boards with a pesticide?")

Not only that, but if you spray rough sawn wood, sell it, and then the customer planes it off, are the bugs inside dead? Nope.

If you apply any pesticides as a business, are you a licensed pesticide applicator?  I used to have a Private Applicators Permit, but not a professional one, and my insurance told me I was opening myself up for lawsuits.

I remember the day I quit using any chemicals on my wood, I had a simple hand sprayer next to the sawmill, (I later figured out I was spraying it at such a low concentration, I was wasting my time) and a customer saw it, asked if I used chemical on my wood, and after I said yes, they walked out.  Simple as that. 

About once a week I still get asked the same question.  Now I just say "Nope, no chemicals touch my wood."

[mudfarmer]

Very enlightening discussion!

YH what do you use for blade lube to keep the no-chem customers happy?

Thankfully we seem to be outside the PPB range, mostly only have trouble with pine borers if I let logs sit around too long A heat chamber to be able to sterilize is "on the list" but the list is... so... long.....

[YellowHammer]

Good point, I never thought of that, I use diesel as a band film but maybe I should say "No pesticides" touch my wood.  The amount used is very little, a drop a cut, give or take (many times, I have the Lubemizer turned completely off, but do turn it on to clean the band when necessary, so I'm not sure it that would qualify as more than "incidental" exposure and as I say in my videos, "If you can see it, smell it, or tell it's there, than you are using too much diesel."  

In the old days, when I used water, I would add pesticides to the band lube while I was sawing and I stopped that because real quick I realized there wasn't enough getting to the wood as it would get wiped off at the entrance of the cut.

   

[mudfarmer]

Thanks, that makes sense Maybe just have to switch to biodiesel  I have warned people about bar&chain oil in sawdust from my firewood yard. Still incidental but sounds like a lot more than you are using for diesel.

[Machinebuilder]

Thanks, I have sprayed boards with Boracare and am now trying Timbor. I mix it according to the label instructions.

I should call and see if they sell direct, the company is very local to me.

As a hobbyist a kiln isn't likely for me.

[Don P]

I use Solubor, Beau-Ron, etc. Those are the ag labelled bags of Disodium Octa borate Tetrahydrate available locally at the farm store and about half the price of the pesticide labelled forms of DOT. Chemically they are identical and share the same CAS (chemical) number. It all comes out of the same hole it just goes into different bags. If you are a legal PCO, pest control operator, then you need to stay on label. If you're already a chemistry felon I don't think labels matter all that much.

Our soil tests always come back low in boron, that is the agricultural source. I can land apply my ag borate infused planer shavings and be considered organic. If I applied a pesticide labelled borate residue it would not be considered organic.  Life sure gets tedious don't it 

[Ianab]

Correct me if I'm wrong but didn't the WoodDoc (Gene) say one time that the PPB couldn't or wouldn't bore into planed lumber?

I think, "much less likely" would be the correct term. Once the bug figures out it's wood, they look for a small crack to insert their eggs into. On a rough sawed or old weathered hunk of wood, there are plenty of opportunities for this. On a planed board, not so much, but they might find a tear out / surface check etc that's suitable. So it's not 100% sure. Finished furniture is even less likely to be infested, but still not 100% as there may be unfinished areas under or behind. 

Or the bugs could have got in before the wood was planed

I prefer to stick with the naturally durable bug resistant woods, I've never found bugs in dry Monterrey cypress or Port Orford Cedar. Although they will get into it when it's still green, they don't survive once it dries out. Local pine is generally all sapwood, and the local borer will get into that, dry or green. Different bugs, but as YH says, bugs is bugs. I've Borate dipped boards to discourage that, and it seems to have worked. No bugs coming out of the B&B pine wall in my workshop anyway. Borate is the lowest level of pressure treated here, and only rated for indoor use, as it's water soluble. But it's also not very toxic to pets / animals, compared to CCA treatments. The warning label simply says not to eat it, get it in your eyes or breathe the dust. 

Like Don says, it's sold as a trace element to add to fertiliser if your soil is naturally lacking, with no regulatory control like actually poisonous stuff. 

[customsawyer]

My chemical guy is spraying for "pest". He sprays around the building and checks the termite traps. The wood going in the store has been through the kiln and was sterilized. When It comes out of the kiln, I let it cool for a day in the store, and then run it through the planer. Then right back into the store. I'm not as worried with my pine and cypress and do fairly low volume on the other hardwoods.

[taylorsmissbeehaven]

Thats pretty funny Don! The fine print of life can really be confusing. Timbor has been my recent go to but my thoughts on setting up a small kiln may be justified if I continue down the path I think Im on. Much/most of the lumber I cut is for personal use but its nice to be able to sell enough to pay for bands ect. This is great info thanks to all

[Magicman]

Timbor and Solubor are the exact same product but since Solubor is classified as a fertilizer it is much more economical:  LINK

[YellowHammer]

Timbor and other "pure" DOT are wettable powders and have limited penetration into the wood, basically, a pure surface treatment.  These are not as effective as enhanced products such as Boracare, which are mixed with glycol and helps soak into the wood, up to 1/4" which is better than not.  If the surface treatment is removed, such as logs then split or milled into beams, then the protection is gone. 

The glycol is added as a penetrant, (read the label) to overcome the weakness of a pure surface treatment for a common use of a whole or partial log in a modern house construction, i.e. the installation of a reclaimed barn beam.  Although sprayed as a surface treatment, it does not kill the bugs in the beams until they emerge and pass through the treated area.  Hence the term I use for such beams: "A nest watching TV at the same time you are".  When informed that a homeowner has installed not just one, but several nests in their home, they will very quickly do a little freak out, and run for the hills.  When asked what to do, I simply tell them to ask for a professional, licensed exterminator to inspect and treat, and sign off on it.  Not my problem, that's why I don't sell logs, beams, or reclaimed wood.   

I had one customers come to me and ask my advice as they were seeing "little bugs" coming out of the old barn beams used in their multi million dollar lake house.  I told them to ask how the log beams had been sterilized, and the customer said the contractor said they had been sprayed with a non enhanced DOT product, and was told by the seller "It would kill everything."  I said "Nope, and don't take my word for it, read the label, it is surface treatment only, go see a pro exterminator or a lawyer, or both."  The customer stood there, husband and wife with their mouths handing open, and said "No, no way", they had been assured the bugs had been killed.  So I laughed, said "Obviously not if they are coming out of the beams and landing on your big screen TV" and so I downloaded the product label real time, texted it to them, read it to them "Surface treatment, penetration to 1/8" and they left doing the "freak out."  I'm not sure what happened after that but they were more than upset.

[Don P]

YH and I were writing at the same time so he covered some of this.

The old timers have heard all this before. Timbor/ Solubor, etc ... make sure you get the wettable powder not the time release granule form of boron.

Boracare, Shellgard, etc contain some form of glycol, Boracare uses ethylene glycol which is toxic, others use non toxic polyethylene glycol or propylene glycol, or one of the other non toxic glycols. Glycols are a slow evaporating alcohol, "permanent water". Their only role is to keep the wood wet longer to let the borate penetrate dry wood deeper. Use solubor on green wood and avoid the cost of trying to do a less effective treat to already dry wood using expensive and potentially more toxic formulations of borate.

That is important to understand, wood has to be at fiber saturation levels or above, free water present in the wood, for borate to move either in or out of the wood. Its mobility is by diffusion. It travels on the wet from levels of high concentration to areas of low concentration as long as there is free water for it to diffuse in. It is salt water diffusing in fresh water until it is all at the same concentration. There is no better time to apply than right off the saw.

[Magicman]

I have no idea whether it does anything but I always add a squirt of dish soap to act as a surfactant.

[doc henderson]

A dash of dawn doesn't hurt anything. we used to add it to sheet rock mud, to help it smooth under trowel easier.

[Don P]

Absolutely, try it without and then add just a little and watch how much better it "wets out" the wood, those pesky air bubbles between the wood and water disappear and all of the wood gets wet.

[caveman]

We add dish soap to DOT in the sprayer and mix with very hot water, which dissolves the DOT powder very well. 

DonP, didn't you put some food coloring or other dye into your DOT spray to determine the depth of absorption some time ago?

On the question to build a kiln or not, building a small kiln is probably a good idea.  My uncle builds a lot of small craft things in his shop.  He built a wooden box, insulated and sealed it well.  With one lightbulb, it gets hot enough to sterilize wood.  We did something similar to kill termites in a cedar mantel piece prior to making our hot box.  

We plan to eventually build another solar kiln that also has the capability to be heated and held to 160* for setting pitch and sterilizing.  Moving wood from a drying kiln to a sterilizing kiln does not follow YellowHammer's rule of "...saving steps".  I hear JMoore remind me of that rule too often.

[Don P]

I mixed curcumin (turmeric) in a solvent and painted that on the fresh cut ends of boards I had rolled borate on about a year before. I wanted to see how deep the mix was penetrating. Boron and curcumin make rosocyanine, a bright red compound. 


Nisus sells an indicator solution, that is it. If you read some of the test reports from the RTA, Railroad Tie Association, they were using the same indicator to test long term efficacy of borate in ties.

[longtime lurker]

I'm just going to point out that the law is the law.

Now I don't claim to have any great understanding of the particulars of the law pertaining to preservative treatment of wood in any jurisdiction other than my own, but certain principles are just about sure to apply regardless of where you are.

One is that you have to define treatment, and part of the legal definition of what is or isn't treated is the retention level of the treatment solution. You must hit a certain level of chemical in/on the wood for wood to be classified as treated to the various hazard classes. My 10 second google search turned up a US Forest Service paper saying that for wood to be passed as borate treated it had to have a retention level of 0.17 pounds per cubic foot. Did a bit of maths to convert that to metric and checked against the Australian standard and that's probably H1/H2 hazard class.

Now the thing I'm going to tell y'all is that there ain't no way you are going to get 0.17 pounds of borate into every cubic foot of lumber by spraying it on and stickering your boards out.  Spraying like that puts borates on the wood not in the wood. Sure you get a little bit of helpful diffusion but that's about as limited as Don's rosocyanine picture indicates and that hasn't even got full penetration on the sapwood.
(total penetration of all sapwood is another technical determinant between treated and untreated lumber)

Now the rules being the rules if your lumber can't hit the retention levels to be classed as treated then it must be classed as untreated, even if you sprayed it with borate solution.

So while individual mileage will vary - and I'd advise anyone thinking about it to do their own checks on retention levels in whatever jurisdiction they happen to be - I would have zero hesitation in spraying borates onto stickered lumber in a greenmill type setting. You just can't get enough salts into the wood to make treated lumber that way. Just sayin'.

[YellowHammer]

That is a very good observation and point, and one to certainly keep in mind, especially when selling wholesale or even treating green as LL says, if that if those limits are not reached then the wood is not "legally" treated anyway. 

However, that is the definition of what constitutes treated lumber but that does not define the allowable exposure or hazards, either short term or long term, to humans as published by the CDC, NIH, or OSHA as well as the label of the product. Those amounts may be much different, and would also be different as the pesticide undergoes its multiple phases of application or state of wet, aerosol, or dry.  Most hazard use hazards labels do not list concentrations of exposure limits, but are more broad and blanket statements, but since they are on the label of the product itself, would be used in the lawsuit, or are the ones used by easy access by the user, simply because it's pn the label or published by the manaufacturer. 

For example, on the label of Boracare it says, and I quote "Use Restrictions:  Do not use in edible product areas of food processing plants or on countertops and other surfaces where food is prepared. Do not use in serving areas where food is exposed. Do not contaminate feed, water or food. Do not enter or allow others to enter or occupy treated areas until spray has been absorbed into the wood. Treated areas must not be occupied during application."  Pretty definitive and unattractive to the average woodworker.

Look at the manufacturer's label for Timbor, it clearly states it is Classed as a Reproductive Level 2 Hazard, which means "Substances are classified in Category 2 for reproductive toxicity when there is some evidence from humans or experimental animals, possibly supplemented with other information, of an adverse effect on sexual function and fertility..."

So, as I mentioned earlier, the are very definable hazards associated with at least these products.  Also as I mentioned, it is this information that will turn off most customers immediately. 

To make consumer perceptions even worse, there is a huge amount of distrust when dealing with any pesticide, herbicide, or pretty much anything.  How many people have been spraying Roundup their whole lives thinking it was safe, and now find out it is far from it?  How many people buy water filters for their home ice makers in their fridge, after being told by their city managers that their tap water is perfectly safe to drink?  Just this week, it was "discovered" that the dye in Oreo cookies "may" be a carcinogen, and who would have thought that baby powder or sheetrock had contained asbestos?  This news is pervasive and constant, and fills the consumers perceptions, whether overblown or not.

As an experiment, lay out two pallets of identical wood, each with a big sign on them, saying "This one sterilized by heat, and not exposed to pesticides or chemicals of any kind" and on the other, a jug of Boracare or Timbor sitting in top of it along with a printed manufacture warning label, along with a sign saying "Sterilized by Pesticide" and see which one sells better.

Also, I am just stating my perceptions and positions, people are gonna do what they do, and everyone should make their own decisions and judgments.  From a toxicity standpoint, Boron products are very safe, especially compared most other pesticides.  However, do you want to end up in court with a young lady who can't have a baby for whatever reason and who subsequently found out that her husband bought some wood from you, treated by a pesticide that, when she read the label, was listed as a possible reproductive hazard?  Not me, and that is not as far fetched as it sounds.  Just saying.....   

[YellowHammer]

Here is a shot of the Timbor label.  It is pretty stark and definitive. "H361: Suspected of damaging fertility or the unborn child."  

[Don P]

Well, the thing is, it is one of the few chemicals that can cause a male mammal to Uh, lose interest. Which is why I have no problem with adding it to a deer lick. I'd like nothing more than to take the lead out of their pencil. So the other place besides Boron California that it is prevalent is Afghanistan. Now think about where the men are bat poo crazy and shooting one another with AK's, Don't ingest the stuff, it has low mammalian toxicity but don't make it part of your diet.

[longtime lurker]

That's a very valid point  Robert - Perception is as much a reality as fact, regardless of whether it mimics reality.

Fortunately I live where I do and if the day comes where some young lady who cannot have a child wants to sue me over the presence of chemical compounds in the wood her house is built from well she can have at it. Under state law the sale of untreated lyctid susceptible wood here is prohibited for structural applications and effectively all construction timber is treated to at least  H3 level. And once you have a plant you just treat everything, because most builders won't build with anything not treated even if it doesn't have to be... the perception being that the use of untreated lumber could get them sued if termites moved in and ate the house out at some point in the future.

And of course once you start pressure treating you find out that CCA is cheaper and easier to use than borates. CCA is getting a lot of push back over the perception  (rather than the reality) of A though, so now most have swung to ACQ or Tan E (copper azole).

Sooo... we make it all black, then plane the treatment envelope off as required. Because a piece of wood that's been treated has been treated, even if the treatment has been dressed off. Which is absolutely as preposterous as saying a piece of wood sprayed with something as benign as borates is dangerous after you machine the surface layer off.
It's a crazy old world right?

[YellowHammer]

That's interesting, everything used as structural is generally treated in some way?  What about studs and stuff like that?  Can the small operator do this, or is the wood shipped to treatment facilities and returned for sale?

Here, some of the stores sell reclaimed boards with frass volcanos and bugs actively crawling on the floor.  One guy told me he felt like he had to take a shower when he got home.

I got this email this morning from a new potential customer: "My wife has settled on butcher-block for the countertops.  I'm curious, are the woods you normally have safe for food preparation, or have they been sprayed or treated with bug killer?" 

This is typical, and I could go into along dissertation about the safety of pesticides, exposures with him, etc, but the easy answer I e-mailed back was "No pesticides have been used on my wood, I sterilize all my wood with heat in excess of FDA guidelines."     

[longtime lurker]

The way through the minefield is to follow the law without breaking the law while exploiting every gap, hole or loophole you can. I don't know much about pine operations but they are mostly larger, or at least large enough to have a pressure treatment plant. All pine framing studs etc) is treated and KD, usually LOSP for internal applications. Pine is also treated usually with CCA for external useage. I don't know of any small pine operators at all, smallest guy I know runs about 5000m3 a year which would be somewhere around 1MMBF at a guess based on 50% recovery rate.

Hardwood gets a lot of mileage in construction here due to the high strength and natural durability of most eucalypt species, and hardwood mills tend to be smaller.  Take off the twenty largest mills and the average would be somewhere between 5000 -10000 m3 so probably recover 500-1000 MBF. I'm on the bottom end of that group FWIW

Anyway AS2082 Visually Stress Grade Hardwood  (national structural grade rule) states that lyctid susceptible sapwood will not exceed the limits of want and wane which are proscribed as up to 1/2 the thickness of an edge or 1/3 the width of a face. So couple of things there... you can have lyctid susceptible sapwood up to those limits with no issue ( good luck trying to sell that though but I'm sure some people do)... if the sapwood isn't lyctid susceptible it's good, in fact you can have as much lyctid non susceptible sapwood as you danG like because it doesn't say you can't.... and you can treat lyctid susceptible sapwood which makes it not lyctid susceptible sapwood with chemicals, or reduce the moisture content enough to not support wet wood borer species with a kiln or yanno.... just don't sell wood that contains any sapwood. Just follow the law to the letter right???

States have different laws to complement that. In Queensland the use of lyctid susceptible sapwood in structural products is totally prohibited, so you cut sap free or treat in those species. Every state also has "fit for useage" provisions which require the use of suitable species to the application. Or you can cut with lyctid susceptible sapwood and send it interstate to a place where it's moot. That happens.

Most little mills either stay in a local market selling sapwood free or non susceptible species, or sell to a wholesaler who has a treatment plant, or stay in the niche product marketspace where you don't have to worry about this stuff except as a quality thing.

Me... I treat. Borate treatment to the requisite loadings can be done without pressure treatment and I've done it for years. It's not a spray and stack process though but I can hit retention levels on a 24HR hot soak cycle. Borate treated timber here is classed as H3 south of the Tropic of Capricorn but only H1 north of it.... worst termites in the world live hereabouts. I like borates as a treatment solution... natural wood colour, the right mix helps inhibit collapse in collapse prone species, with the right loading you can hit all the fire retardent ratings and done right to get proper diffusion it's not just planed off like an envelope treatment. I use borates for the cabinet and joinery species, flooring and internal useage products where treatment to H1 is sufficient. With framing I stick to my sap free durability class 1 species or I send it away for pressure treatment and ship it back home. But I'm pretty much at a point where a treatment plant is on the priority list because the value of the lost volume cutting sapwood free is exceeding the capital outlay to install my own plant and recover it.

In Australia I would say more commercial hardwood mills have pressure treatment plants than have kilns. Green off saw hardwood framing is still common here which explains that, but also the fact that it's cheaper to run a pressure treatment plant than run a kiln, and that treatment is forever whereas KD is only good until it gets wet.  So compared to you guys it's a different playing field but similar outcome - those who get it right go forward and those who cut corners and sell wood full of grubs fall behind

[YellowHammer]

That is amazing information, much seems completely different than in the states here, especially the identification of non insect prone sapwood species, and the differentiating between the different locales.  Also, wow, you sound like you've got another construction project in the future, that will be an interesting read for sure!

 

[longtime lurker]

My construction projects list seems never-ending: I'm worse than you in terms of vertical integration because we log as well...about 1/3 of my log supply is in house... the business model has a lot of moving parts.

The analogy I use for a sawmill business is that it's like a truck... if you want more out of it you can't just get there by fitting a bigger engine if the gearbox and diffs won't handle more torque. So do you start at the back and work forwards or start at the front and work back? And while all that goes on the kids still need the driven to school every day and you're still up for new tyres and general maintenance and stuff.

The three years ago pie in the sky "we might drop some fill there cuz one day it might be useful" expansion of the log yard is now at "it needs to stop raining because I don't have enough room". It'll finish this year.
I've got one shed badly needs a new roof and another not far behind it.
Electrical upgrade for the greenmill building.
The handstand between the two main building clusters needs serious love with a grader, rollers and resurfacing.
The log yard loader needs replacement or a serious downtime overhaul. Poor old doll has done 15 years with little more than grease and oil changes and she needs some serious love.
Do I go with a high speed SLR or will a Baker board edger like YH's actually stand up to this type of wood? How I'm doing it is way too slow and straight finished product is what's bringing the big punters in.
Need more kiln!
Treatment plant, but where do I put it?
Electrical upgrades, then more electrical upgrades.
Log truck? Log Transport and  timber back and forth to treatment is over $100k for the year already and we've been weather constrained. I've only said no more trucks after selling the last three but things have changed again.
Greenmill. Greenmill. Greenmill.... the solution to that starts with a complete new shed. New shed would open up the current building for a treatment plant, air drying storage, kilns out where the run stacks are which creates space in the drymill shed tomakeitflow better. .. let me integrate the sawline components I've got lying about and a better resaw as well...  yeah be $600k just for the building  that just has to wait...
Skilled staff, where do I find them, I don't have time to teach people from zero myself. And an admin person, I take 100 calls a week and then there's quotes and estimating and logistics and payroll and A/R and A/P... no wonder I get nothing done.

There's a guy gets around the forum with a tag line goes something like "the easiest way to make a million dollars with a sawmill is start with two million". I don't think he's factored in inflation 

Treatment plant be 2 years out yet.

[Peter Drouin]

It never ends with sawmills  I talked with Wood Mizer today. They want $17,500 for a 12' log deck.

[longtime lurker]

And that's the problem... I've got two big Gibson decks under cover in the yard but installation means either a pit - never a good idea in a place that gets 200" of rain a year - or elevated construction which puts things too close to the roof. Same issue with the 54" band resaw, you can't get within 10 foot of my roofs without cooking. Great for air drying though.

https://forestryforum.com/gallery/displayimage.php?pid=353572.

I could extend the greenmill shed this way about 30 yards and excavate out the bench there to get things to work  but the shed is a touch narrow to lay things out right and  it can't be accessed from the far end or much of the far side in that picture. And shoehorning a full sawline in there would leave me short of covered storage and I'd still need somewhere for a pressure treatment plant.

https://forestryforum.com/gallery/displayimage.php?pid=353571

Or once my little earthworks project is completed and I can use the right side for log storage I could put up a new shed in the middle of the log yard purpose designed for the sawline. Kilns could then go on the bench behind the current shed with enough separation that I don't lose sleep over burning everything down, treatment plant could be inside it, and enough pack storage to make things work. That's the sensible do it once do it right answer. (The best best answer though would be knock the house out and put the next shed there but yanno... new shed and new house at the same time is not happening on my chequebook)

Problem is that that new shed wherever it goes at today's prices will cost the best part of half a million dollars before i start putting things inside it, and without at least 10 years of guaranteed log supply it would be awful adventurous even for me.

I'm still having fun anyway, and it'll all sort out given time.  Meanwhile we make do, little steps one after another.