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"Siberian house" of pine thermal.

Started by serg, January 29, 2013, 11:01:57 PM

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serg

Hello friends!
I made a new design of drying wood. Volume of 40 m3. Convective drying with thermal function. I had the idea of ​​drying and thermal pine timber large volume. I did not know how the quality and uniformity of the thermal drying, the movement of hot air in the chamber. I made a drying technique empirically way. Then began to saw boards, the quality is good. Period of drying and thermal pine logs 12 days. Humidity 8 - 10%. Pine timber has a diameter of less thermal 2-3 cm pine green. See photos of work.
Sergey.











Jay C. White Cloud

Hey Sergey,

Very interesting method.  How do you get a moisture reading in the center of the log, by core sample?  Has there been any cost studies of comparing working with the dried timbers/logs compared to traditional green timber/log work?  At what temperature do you heat to and is there any case hardening of the logs.  Very exciting work, look forward to hearing more about it.

QuotePine timber has a diameter of less thermal 2-3 cm pine green.
Could you explain this further, I do not understand this measurement as it relates to the timber/log.  20 to 30 mm is that correct?

Regards,  jay
"To posses an open mind, is to hold a key to many doors, and the ability to created doors where there were none before."

"When it is all said and done, they will have said they did it themselves."-teams response under a good leader.

scsmith42

Sergey, I don't always comment, but I do ALWAYS enjoy your posts!  Thanks for sharing.

Scott
Peterson 10" WPF with 65' of track
Smith - Gallagher dedicated slabber
Tom's 3638D Baker band mill
and a mix of log handling heavy equipment.

tyb525

Sounds like 2-3cm is the overall shrinkage from a green log to a thermo-treated and dried log.
LT10G10, Stihl 038 Magnum, many woodworking tools. Currently a farm service applicator, trying to find time to saw!

Den Socling

Hi Sergey. Welcome back. That is beautiful work, as usual.

Nomad

     As always, impressive workmanship!
Buying a hammer doesn't make you a carpenter
WoodMizer LT50HDD51-WR
Lucas DSM23-19

serg



Hello colleagues!

       Thanks nomad
Jay C. White Cloud, thank you for your interest and questions.

And I am grateful to all members of the forum for your comments and answers'.

I will try to answer all your questions.

The process of drying and heat-treatment of green log (unbarked wood) takes from 8 to 12 days. The temperature is 165 °C; the time of heat-treatment is 24 hours.

We measure moisture using incorrigible electrode with Teflon conductors ( wires). We place them in the middle of the log.

The overall shrinkage is up to 30 mm. So the green log with a diameter 400 mm, after drying and heat-treatment has diameter 370-380 mm.

As for the studies, we cooperate with associate professor Mrs. Elena Vladimirova from Moscow State Forest University, and she uses our samples in her work. At the present time she is studying logs heat-treatment with her master students. She has an article in English about properties of some wood species, which were heat treated in boards using our method and cameras.

Sergey

Mooseherder

Is there a Market for logs with bark on them Serg?

serg

I didn't reply to the question about cost of the drying and heat-treatment of logs.

The drying chamber with volume 40 m3 has generating capacity 73 kW. Power costs are 350-450 kW on 1 m3 of logs. Also you have to add the cost of leasing of premises, salary for the workers and the cost of loader. So it means that the cost of 1 m3 of heat treated logs is 70$.

In Russia 1 m3 of green logs cost 100$ +70$=170$ for 1 m3 of heat treated logs. And this is ready material for the round log construction building.

There is no need to wait for 4 years until the shrinkage of wood will be steady.

The alternative to this material is glued laminated lumber from pine lamellas (thickness 52 mm). The price of the glued laminated lumber is 700$. It was very fancy product in Russia, but nowadays the demand is decreasing as customers want to have a natural wood without any glue. However natural wood has some weak points.

The wooden house has to stay 3 years until the shrinkage of wood will be steady.

During these 3 years you have to make 2 times a year chemical treatment to protect the house from the mold, fungi and insects. So the price is increasing.

When the house is put in commission you have to make 2-3 caulking (it's the sealing of joints and cracks). As a result we can see that house exploitation is quite costly and not eco-friendly. We think that thermally modified logs can solve these problems.



Mooseherder

As for the market,

there is no market of thermally modified logs in Russia and, as I know, in other countries too. I hope to develop this market. And it is absolutely new product.

It's the alternative to glued laminated lumber with a size 180х180 mm. As I write before, the price of the glued laminated lumber is 700$, and the price of environmentally friendly thermally modified round logs is 200$. The difference in price is 500$. The diameter of log is 350 mm, and its weight is lower.

I have an offer to give the first price for the thermally modified logs with diameter 350 mm - 650$. It's possible to make dumping price.

I don't know the cost in USA for the metal, electric energy, salary for the workers. Also I don't know the cost of the pine logs. If I will know all these prices I can calculate the cost recovery of the drying chamber for thermal modification.

I wanted to ask, do people build houses from glued laminated lumber in USA?

As I know, such technologies as timber-frame housing and "Fachwerk" should be constructed from solid wood. And the air drying takes a long time.

In thermally modified wood we get stable geometry and shape, also the operational moisture content is not changing throughout the year. The log in first hours after heat-treatment has moisture content 2.5 - 3%, after 7 days - 5%, after 12 days – 8%.

Sergey

Mooseherder

Serg,  Are you going to remove the bark after they're dry or leave it on?

beenthere

QuoteI wanted to ask, do people build houses from glued laminated lumber in USA?

Serg
Yes they use glued laminated lumber in building houses for structural purpose primarily.
Beams and headers mostly, I'd say.

Will your treated logs compete with glued laminated lumber for strength properties?
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

tyb525

I think he means glued timbers for exterior use? Not sure on that one.
LT10G10, Stihl 038 Magnum, many woodworking tools. Currently a farm service applicator, trying to find time to saw!

Jay C. White Cloud

Good Day Sergey,

I commend you on your creativity with your approach to building your log structures. I wish you all the best in marketing this type of modern log home.  You seem to have found a cost effective way, in your market, to expedite the shrinkage issue that is prevalent with certain types of log architecture.  With your system I can see many of the traditional log joinery methods not needing to be used or not used as extensively to compensate for shrinkage.  This would also mean your labor force does not have to be as skilled in joinery or assessing the proper orientation and use of a log in the structure they are building.  From a business and marketing perspective this is logical.  You may be forgoing some of the traditions of log architecture, but you are making the structure easier to build for a labor force with limited traditional building experience.

Your market may be in a different economic format than ours as well.  The foresters and loggers of the forum would be able to compare better than I.  In my market in Vermont, your prices seem very low, which would lead me to believe that you method would not be financially viable in our market or in the E.U. - only in Russia.

1 m3 = 35.32 ft2 = 423.8 board feet

$170 ÷ 423.8 = $0.40 / board foot for kiln dried logs


I am curious at what price you are asking for just the log structures per m2?

Have you had any issues with the logs expanding too much after they begin to take on ambient moisture during stabilization after being kiln dried, or do you wait long enough for them to stabilize before placing them in a structure?

In most traditional timber framing and log architecture, you want to work in green wood because it is easier to cut joinery and the building is stronger when it drys in place.

How difficult is cutting joinery in the logs after the kilning process, compared to cutting the joints traditionally?

Why do you not remove the bark off the logs prior to kiln drying them, wouldn't they dry better with the bark off?

Thank you for sharing all you information with us and answering our questions.

Regards,  jay
"To posses an open mind, is to hold a key to many doors, and the ability to created doors where there were none before."

"When it is all said and done, they will have said they did it themselves."-teams response under a good leader.

serg

Thank you all for your comments and answers!

Mooseherder
I remove the bark after drying. It's taking off very easy after heat-treatment.


beenthere
In 2013 I am going to make a comparative research between glued laminated lumber from common pine and spruce and glued laminated lumber from thermally modified wood lamellas. This work will be done by Mrs. E.Vladimirova (PhD from Moscow State Forest University).
The research that was done in Moscow state forest university with pine and spruce, shown that when we use temperature 160 °C there are no big changes in physical and mechanical properties, the properties are even getting better. When we using temperature >185 °C there is decreasing of bending strength of pine wood. And as for the spruce, it's increasing bending strength to 15%.
tyb525
I mean houses for living from glued laminated lumber (it's a square beam glued from wood lamellas). This material is used for bearing walls and division walls in such a houses.

May be you have another term for this in USA.
An application of the glue between lamellas creates the barrier for air circulation through the wood. In Russia such houses considered to be not quite ecofriendly. 
Jay C. White Cloud
Thanks for your reply and a words of encouragement!
Shrinkage is a big problem in wooden house building.
Thermally modified wood can solve this problem. I want to add to this other positive points: extinction of insects, fungus disease, and mold wouldn't appear on thermally modified wood. The color is uniform through-the-thickness of log and it's really beautiful. I think that houses can be built in substitution for repair houses and buildings, for young marrieds, farmers, etc. It's profitable to build such a houses using light foundation on the seaside, on the mountains.
I agree that in Russia we have few qualified labor force in wood house building with traditional building experience. In the old days we had much more professional carpenters and woodworkers.
I didn't fully understand this paragraph:
«Your market may be in a different economic format than ours as well. The foresters and loggers of the forum would be able to compare better than I. In my market in Vermont, your prices seem very low, which would lead me to believe that you method would not be financially viable in our market or in the E.U. - only in Russia.»
If it is cheap, then is it bad? I showed that the cost price and the sales of the new product will give a good profit and extra cost/ added value.
There are no problems with the thermally modified logs in a humid weather, the doors are opening and closing, the swelling of logs is much lower and the geometry is stable.
It is possible to field assembly every day of the year. You can start to cut joinery after 8 – 10 days as experience shows. First of all the log should be cool to the environmental temperature, than you have to remove the bark off the logs, usually all this procedure takes 8-10 days.
On this forum I shown timber frame house. My partner, his name is Arthur, dries a pine beam (200х300 mm) to the moisture content 6 % in a vacuum drying kiln for 22 days. He worked with thermally modified pine beam (200x200 mm) and saw that the instrument is working well. There is no difference in cutting joinery in the logs after the kilning process, compared to cutting the joints traditionally. If we make the drying and heat-treatment of oak, the hardness is increasing and the instrument should be from the strong steel.
I will ask Arthur to give his opinion on this forum, he has already registered and his English is quite good.
We do you not remove the bark off the logs prior to kiln drying because it's better to make drying and heat-treatment with the bark on.
I am ready to answer your questions.
Sergey.




Jay C. White Cloud

Again Serg,

I am so impressed.  This is the first modern approach to timber framing and log work that I have really liked and thought was an improvement in many ways for certain applications.  Please don't stop posting, this is really a wonderful process you are sharing with all of us.  ;D

Regards,  jay
"To posses an open mind, is to hold a key to many doors, and the ability to created doors where there were none before."

"When it is all said and done, they will have said they did it themselves."-teams response under a good leader.

Den Socling

Sergey,

Your English has improved dramatically. It's nearly perfect.

Den

jueston

i love that window trim, especially the detail at the bottom. do you have pictures at the rest window trim?

Autocar

Thank you for scharing, very interesting. Your logs sure are beautiful in those homes your building, very cool !
Bill

serg

Den, hello!
I do not speak English. I help Lena and Arthur.
I have the material production of small architectural forms. There is a video which shows a Russian TV assembly of complex thermo pine.



The administration says that the forum advertising or information?
I can continue the theme?
The photo ash, pine, pine thermo humidity is different for the 6 month.
Sergey




kderby

Please continue.  This exposure to new and interesting ideas is valuable to me.  Thank you for posting it.

The picture of your treated and peeled pine is stunning! 

Are you heating the wood using steam or another heat source?

Serg, Lena and Arthur, Thank you again!

Kderby

GeneWengert-WoodDoc

Question: How does the moisture get out of the chamber?

Question:  How is the chamber heated?  To get that hot, do you use heated oil or high pressure steam?  If steam, is the steam injected into the chamber as is done in superheated steam drying?

Question:  What is the temperature you use for drying?

Comment: We know that the temperature of 165 C (330 F) creates substantial strength loss in pine...maybe 30%.   As a result, such heated wood could not be used in structural applications according to U.S. and Canadian laws and building codes.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

tyb525

According to the university of Moscow 160C doesn't reduce the strength of pine, but 185C and above does. I don't know who is right there.

I think this technology is better for hardwood lumber and pine logs, than pine lumber. I see Serg marketing it for outdoor lumber and whole logs where rot, insect resistance, and stability is important. It wouldn't be needed for interior framing such as rafters, where strength is more of an issue.
LT10G10, Stihl 038 Magnum, many woodworking tools. Currently a farm service applicator, trying to find time to saw!

GeneWengert-WoodDoc

It does weaken southern pine.  We begin to see weakening around 240 F.

That would be a concern for decking, stringers, etc. which are all structural.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Den Socling

Gene,
If you look at the picture in the first post, you'll notice pipes on the wall. Hot oil is circulated through this piping. The kiln operates as a "typical" vac kiln until the wood is dry. In previous chambers, Sergey had a condenser but I don't see one here.
Den

Arthur Beck

Hi everybody!

I'm Arthur, Serg mentioned about me above. He asked me to translate his replies to last questions and place at the forum. So, doing this.

Hello, friends.
I asked Helen and Arthur to participate the forum to help me with communication. Thank you for your questions and answers. I'll continue to acquaint you with my thermowood experiments.
I've used the new design of kiln with natural air circulation. Dan is right: vacuum kiln collect moisture by mean of condenser with cold water flow inside it, while in the convective kiln with thermo treatment the steam exhausts to the atmosphere by mean of supply/exhaust valves. There are pipes with oil inside the kiln. I don't use steam under pressure.
I use temperature 150 – 190 oC (F= 300 – 375)
I'm quite agree with you that pine loses bending resistance. But it increases its hardness, swells less, no insect infestation. I can make the rapid kiln drying of pine at 110 oC (F=230) and check it for natural strength weakening. But nevertheless I consider unpeeled log drying  at 170 oC (F=340) for 8 days to be a good result.
It's important. Please pay attention that Moscow Forest University survey concerned fir and spruce, NOT pine at temperature 160 oC (F=320) and resulted 15% bending stress resistance increase! Hope there is no mistake, the experimental spruce was from different regions of Russia and Ukraine, and result was the same.  I'd like to notice this survey will be continued for different temperatures and heating time. For different species properties changing vary.
You know that some natural properties of wood depend on its place of growth. So they may vary under heat treatment.
It could be interesting to check American pine (not Russian) according American and Canadian standards.
I see the physical properties of wood could be increased considerably using composite technology with thermowood. It's separate item and I'm dealing with it now. Let's consider.
The idea is like this. Thermowood  become stable in geometry, humidity invariant lengthways and through thickness, mold and rot resistant, low swelling. All these permit to create new composite materials.
E.g., oak, hornbeam, acacia are very durable without heat treatment. The heat treatment  under  certain conditions even improves most of physical properties. So we could glue up oak and other  hardwood with pine lumber and get the advantages of thermowood with cost  efficiency of pine or spruce (fir).
There is a lot of operation in gluelam production.  Knot cutting out, lengthways gluing by mini-tenon, lamellas gluing etc. A lot of machinery is necessary. We can take low rated solid pine lumber 150x150 mm (6"x6") and glue up 25 mm (1") oak or hornbeam lamellas on both sides. As the result we get 150x200mm (6"x8") composite lumber  with better durability and décor. As well we need less machinery for its production.
In case we use solid heat treated  logs and lumber in compression conditions, no need to use composites.
What's your opinion about this "thermocomposite" technology?
The end of Serg's post.
I am small Traditional Timber Frame Workshop owner. Our vacuum kiln was made ourselves under Serg's supervision. So we cooperate with him and his wife already for a quite long time and our next project now is to remodel our kiln into Thermo-Vacuum. I want to use thermowood (spruce and fir) for outdoor pavilions at first as shown at photos attached. In case I am shure about the rate of thermowood construction properties degradation (increasing?), perhaps we use it for residental timber frames also. Now I rely the data about that matter in this Finnish source http://files.kotisivukone.com/en.thermowood.kotisivukone.com/tiedostot/tw_handbook_eng.pdf. They write almost all strength properties even slightly improves till 180°C (F=350). It could be enough for me they will not degradate. That's why I need my own thermo kiln to get necessary lumber for investigation.
Regarding the "thermocomposite" idea. I am not sure it can be wise for construction loadbearig lumber, especially beams and rafters. Usually 3 or even 4 sides of them are visible, so it would be necessary to laminate not only 2 sides. I think it will be costly. Perhaps it's OK for massive lumber walls to make them more aesthetic and element resistant.



  

  

  

 

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