Finding Uses for Free Sawmill Waste - Cedar Only

Finding Uses for Free Sawmill Waste.

There is a cedar mill less than a mile from my building site. They pay to get rid of sawdust and crappy wood. They waste very little at this mill, so most wood is thin slabs and squared wood smaller than a 2x4 on the thickest end. Milling this into anything is not an option. It has been rejected by a very efficient mill.
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In the thread – A New Building System is Born – I describe how to build monolithic walls similar to but superior to cob from this material when it is mixed with a clay slip.

Test mixing with a Bobcat has shown that it mixes well and holds its shape when dry. It's basically wood chip clay but with a huge variation in particle size. This is to be used as infill only, since it holds shape fine but is highly variable. I wouldn't support a roof with it. I wouldn't trust cob to hold up the roof in this earth quake zone either, thus the positive comparison.
---------------------------------------------------------------------------------------------------------------- I'm looking to explore other uses for this material. Good firewood is plentiful, so forget that obvious one. Cedar can harm garden plants so use in hugelkultur is out. Plenty of good hardwood available for garden use. I'm looking to use it in building, or to manufacture some simple, low tech product.
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OTHER USES FOR A MIX OF WOOD SCRAPS AND SAWDUST
1. I'm thinking that blocks of this material might be something that would sell. I could see them being used to build adobe like structures where weight reduction and insulation value are important.

Adobe blocks are not used where I live. The reasons are simple. Very poor thermal performance, poor earthquake performance and due to this they are virtually unavailable.

An insulated, infill block might find a market with those who want the cob or adobe look without the drudgery and poor performance. The material weighs around 30 lb per cubic foot.

A block measuring 12 inches wide by 18 inches long and 8 inches thick will weigh about 30 lb.

A block 18 inches wide by 24 inches long by 8 inches thick will weigh about 60 lb.

A block measuring 18 inches by 72 inches (6 ft) and 18 inches high contains 13 1/2 cubic ft of material and would weigh about 450 lb. Some full length lumber would be incorporated, thus the greater density. These blocks would be formed to accommodate a fork lift or the forks on a tractor. ----------------------------------------------------------------------------------------------------------------------

2. Sawdust Tarp Wall. ----- A wooden form work holds 2 tarps in place about a foot apart, creating an insulated wall. Cedar is slow to rot and bugs don't like it. Still, I would keep it dry and add some borax or other critter deterrent. Check out threads by Abe Connally of Velacreations. He lives in a warm climate and has contained dirt to build walls in this manner. Mine would be similar to his, but with the insulation provided by saw dust. Dry cedar saw dust weighs about 15 lb per cubic ft. -----------------------------------------------------------------------------------------------------------
3. CEDAR OIL ---- My knowledge of this is very limited. Cedar contains an oil which is valued as a perfume, pesticide and wood treatment. ----------------------------------------------------------------------------------------------------------
4. BRIQUETTES ----- Not sure if cedar briquettes would find a market. Possibly as a fire starter. They would have far less energy per volume than other woods. ----------------------------------------------------------------------------------------------------------
5. Bio char or charcoal ----- I assume that the negative aspects of cedar on other plants are removed during charcoal manufacture which would make it into a suitable soil additive. Probably not a mass market thing but I could use tons of the stuff. ----------------------------------------------------------------------------------------------------
6. Fuel for a wood gas generator. This along with charcoal and oil extraction would provide many opportunities to blow myself up.

That's all I've got right now. Any ideas would be appreciated.

Thank you: Dale Hodgins

(Foot) Pathway material.

Use sawdust by itself as a spreading where you want to minimize plant growth? Don't know what the water cycle would be when sawdust gets soaked.


Rufus

I have seen on youtube videos where people pack sawdust into round bricks with a hole in the center and they burn them for fuel for cooking.

I'm consolidating all of my green building inventions and adaptations under one roof. The thread is called "Dale's Marvellous Inventions and Adaptations." and links to other ideas and inventions. Here's the link --- https://permies.com/t/19303/green-building/Dale-Marvellous-Inventions-Adaptations

Here's an excerpt of the first and longest posting since I started the thing last night. Much of the wood scrap could go into this. ------------------

Charcoal in Green Building - slip coated insulation, cob insulation, infrared resistant plaster, plaster pigment ...

I'm trying to find uses for charcoal or bio char as an insulating material. Charcoal is one of the lightest natural solid materials and it has excellent thermal and hygroscopic properties. Based on this, I've got several ideas brewing. The idea first struck a couple hours ago, so I'm quite excited about the possibilities.

1. Granular charcoal insulation for attics. Charcoal is one of the most insulative materials on Earth. It would need to have a clay slip coating for fire protection as is done with straw clay. Fine and coarse materials would be mixed for maximum effect. I would expect convective currents to be more of a problem than with blown cellulose. This problem can be alleviated with a thin cap of blown cellulose. I've done this with other granular insulation (chunk fibreglass, redwood bark, vermiculite, wood chips). A thin cap fills voids and causes an improvement in performance greater than would be expected based on the R value of the cellulose. --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

2. Granular charcoal mixed with cob for lightness and insulating. By putting a greater proportion on the outer few inches, we could have insulation but still retain the benefit of the thermal mass of a pure cob inner wall. The hygroscopic nature(water absorbing) of charcoal should help moisture migrate through the wall. Charcoal conducts far less heat than does pumice and it has the infrared property to boot. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

I SAVED THE MOST PROMISING ONE UNTIL LAST
3. Ground charcoal/clay paste to give cob walls an infrared and conductive barrier.
(High end foam insulations use an admixture of carbon black in order to impart better infrared properties.) (Asbestos worked well for this but caused health issues.)I imagine using the charcoal paste product in the scratch coat of interior plaster. Regular plaster would be used in the finish coat since we don't want a black interior. Trailers and other light buildings often have a shiny paper product under the panelling to reflect infrared. A layer of charcoal should work even better than this.
A black exterior might be desirable in certain situations. A cob bench in the greenhouse might look and perform well with a shiny black finish.

With some work, I may become the "Henry Ford" of charcoal insulating, and as Henry would say, "You can have your charcoal plaster in any colour you want --- as long as it's black."

Sounds like from the posts, there are enormous quantities to be dealt with. You might not be in a region where livestock are common, but cedar shavings/sawdust would make excellent bedding for animals of all types...poultry, horses, etc. I have seen bales of this stuff for sale in both GA and CA at stores like "Tractor Supply" for livestock and poultry litter....

Here's an idea I've been mulling over for a short time. I envision using a large retort to convert large quantities of cedar scraps and sawdust to wood gas and charcoal. The stuff would be fed into the retort with a front end loader.

There's another very large type of wood that I can be paid to dispose of. Big, awkward tree stumps are almost impossible to process into firewood but once in a kiln, they will char and can be easily broken up with hand tools. A 500 lb stump (dry weight)will yield about 400 lb of wood gas and 100 lb of charcoal. This goes far beyond my need for heat, but good to know if you're planning to open a paper mill or heat a town. I would never attempt anything that big without engineering help and a contract with BC hydro, a pet crematorium or a pottery guild in hand.

Check out Charcoal/Bio-char Production – Utilizing the volatile gasses, reducing pollution and fire risk https://permies.com/t/19523/stoves/Charcoal-Bio-char-Production-Utilizing