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Stabilizing wood and killing insects in wood slabs.

Started by plantman, March 12, 2017, 04:47:22 PM

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plantman

I'm considering milling some large slabs with a chainsaw mill . I might also slab some large rounds to make live edge tables out of. I've seen that most people sawing lumber will paint the ends of the logs with a wax paint such as Anchor seal. And I've seen a product called Pentacryl used to stabilize wood and prevent checking and cracks. To kill insects I've also seen a product called Bora-care. So the question that I have is, "has anyone used other less expensive products for the same purpose of stabilizing the wood and killing insects ?" I'm anticipating that I will simply air dry the wood.

YellowHammer

The best way to kill insects and mold/fungus in wood, especially live edge slabs, where bugs love to live, is with heat.  About 135° and it's ball game for them.  Fast, simple and dependable.  An insulated box with about 2,000 Watts of halogen lights will do it. 

Stress in thick wood and cookies is always problematic.  I have cut both and the easiest and cheapest ways to prevent them is by judicious species selection and milling techniques. For live edge, stay well out of the pith, I like about a third out.  For cookies, its best to mill them at an angle.  Anchorseal is a great product and excels at preventing end cracking.  Not to be simplistic but the best species from a cracking perspective to stay away from are the ones preferred to be split as firewood and concentrate on species that people don't like to split for firewood, such as maple, gum, elm, etc. 

To give you an idea of how much internal stress is in a drying cookie, below is a picture of a slice of poplar in which I made a single, narrow hand saw cut from edge to center.  As the piece dried, it shrank in this Pac Man shape, looking like a pie with a piece misssing.  That's a lot of stress to contend with. 


YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

Den Socling

I believe hollow logs or logs with punky pith crack less when cut into cookies. Without the center, there is less preventing the rings from shrinking inward toward the pith. Of course, you have to end by filling the core with epoxy.

btulloh

HM126

Don P

You had posted part of a Dave Carnell article titled "Chemotherapy for Rot" in an earlier post, this quote is also from that article
Quote
I had two 2" thick slabs of a 14" diameter hickory tree that had just been cut. I treated one with antifreeze and left one untreated. I was looking at wood stabilization, not rot prevention. After about six months stored inside my shop the untreated control was not only cracked apart, but it was sporting a great fungal growth, while the treated slab was clean.

The local history museum wanted to exhibit two "turpentine trees", longleaf pines that had many years ago been gashed to harvest the sap that made everything from turpentine to pine tar. The trees delivered to us after cutting were infested with various beetles and had some fungal growth. I treated them with antifreeze outside under a plastic tarpaulin every few days for three weeks. They were then free of insects and fungus and have remained so after being moved inside and installed in an exhibit over four years ago.

I took three pieces from a rotting dock float that were covered with a heavy growth of fungus, lichens, etc. I treated one with antifreeze painted on with a brush, the second with a water solution containing 23% borates (as B2O3), and left the third untreated as a control. They were left exposed outdoors and were rained on the first night. By the next morning the growth on the antifreeze-treated piece was definitely browning and the borate-treated piece showed slight browning. After two months exposure to the weather the growth was dead on the antifreeze- and borate-treated pieces and flourishing on the control.

This is another way to show drying stress in a cross section. I cut the piece thin enough that it could go out of plane. Tangential shrinkage is usually about double radial. Imagine if you pushed down it would split similar to YH's section. Drying a green planed timber also leaves the once straight edges of the piece convex.


GeneWengert-WoodDoc

Borates. Will leach out if exposed to rain.

Antifreeze is not suggested for wood due to its poisonous characteristics.  Note that polyethylene glycol is safe and very effective...usually PEG300 is used.  You do not want to sell or use wood that has a poison in it.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Don P

Not advocating one way or the other just digging up more info.
We put an awful lot of things on wood that are poisons. I think we need to work through that a little more. Paint and stain also fail over time, they also protect the wood until they do. Borates don't go away with the first rain, or the hundredth. Remember, wood will go away if exposed to the rain  :).

From the Bora-Care MSDS
Quote
SECTION II – HAZARDOUS INGREDIENTS
Material or Component: Ethylene Glycol CAS No.: 107-21-1

From another thread posted to by Carnell some years ago;
QuoteI was involved with antifreeze for its stabilization of wood for a long time before I discovered its rot-killing properties.

The story may be a bit long, but it covers 40 years.

Around 1960 I was in charge of the DuPont research group supporting nylon plastics. Remington had developed a semiautomatc .22 rifle in which the stock was much more than a handle. It was molded of 66 nylon and many of the operating parts were in that molding. At Ilion they demonstrated it to me firing in full automatic in sand, ice, etc. They were concerned about the "plastic" appellation to their rifle. 66 nylon can sometimes be less than ideally tough if it is very dry-a dryness you cannot achieve on planet Earth outside of an oven. We suggested a water soak of the molded pieces, but they feared that might evaporate. So I went looking for a "non-volatile water". In the literature I found Stamm's work on stabilization of wood with PEG. In his first paper he got better results with glycerin than the PEGs, but he ignored that result because it didn't fit his theory that it took a large molecule to "prop up" the cell structure as the wood dried.

We offered Remington glycol, glycerin, and resorcinol as "nonvolatile waters". They started with baths of hot resorcinol to treat the molded pieces, but soon came to their senses and got rid of any treatment except a water soak.

Fast forward 20 years and I had moved to NC and retired. Eleanor was taking a course in sculpture at UNC-Wilmington. Her sizeable wood piece started to crack and her instructor told her to wrap it in a towel soaked in antifreeze. He told her it would prevent cracking and I would know why.

I expanded into treating green wood up to 20"D. 2" thick slabs of hickory and prevented cracking. I made friends with the guys at the NC Underwater Archaeology Unit at Fort Fisher here. They had large tanks of fresh water in which they kept wooden artifacts from blockade runners sunk offshore in the War of the Rebellion. If those were allowed to dry out they disintegrated. They were treating pieces with PEG and sugar solutions to stabilize them. Both treatments required long times in heated solutions. I cadged a musket butt, brought it home, and put it in a bag of antifreeze for a month at room temperature. Then I removed it and let it dry. It lost a lot of weight rapidly as the water dried out and then the weight loss slowed. The piece maintained its shape exactly and even fine details such as tool marks where brass trim had been inletted were preserved. I accumulated anecdotes along the way. The community college boatbuilding instructor remembered seeing large redwood slabs soaked in antifreeze in CA and a guy in MA reported antifreeze stabilization of black walnut rifle stocks during WW II.

The NCUAU people were impressed enough that they enclosed the boatshed at NC Maritime Museum in Beaufort with plastic and set up a system to spray the timbers of a Colonial era flatboat ferry with antifreeze to stabilize them. They recycled the solution and replenished losses. It stabilized everything so they could reconstruct the craft and study it.

In 1986 I took a course at UNC-W on technical writing with the objective of learning how to use a computer in writing. The major assignment was a technical report. I chose ethylene glycol stabilization of wood.

I searched every article on ethylene glycol uses in Chemical Abstracts from 1900 to 1986. When glycol first became a commercial product in the 1920s, it was considered as a substitute for glycerin. Then glycerin was a by-product of the soap industry and most variable in price and supply because it was dependent on the meat packing industry for its basic raw material. Looking at glycol as a replacement for glycerin in tobacco, cosmetics, and food, researchers found it was a potent killer of molds, etc. and couldn't be used in foods.

The ladies here put magnolia branches in glycerin to keep them green for a long time. Drugstore glycerin is expensive, so I stuck some greenery in antifreeze. Overnight it turned brown. I repeated the experiment twice before I tumbled to the fact that the antifreeze was killing them. Then I dug the hickory slabs mentioned at the beginning out from under the bench. The treated sample was intact and unblemished. The untreated slab had fallen into several pieces and sported a large fungal growth. This set me off on more experiments that demonstrated the effectiveness of glycol in killing rot in wood and cured athlete's foot, jock itch, and other fungal infestations of bodily parts.

The story of one of my activities in the last 40+ years.

Don P

Start on page 17 here for water solubility info;
http://repository.upenn.edu/cgi/viewcontent.cgi?article=1116&context=hp_theses

Somewhere I have much of that same info sent upon request from Rio Tinto or US Borax some years ago, I was working on an old log cabin, must have been around '02. Scanning the rest of that thesis quickly, it looks quite interesting. The orange I'm seeing in photos is/was an indicator solution available from Nisus.

Edit;
This is a report on borates from Osmose, there is more discussion of leaching starting around pg 12
http://www.osmose.com/documents/A%20Critical%20and%20Comprehensive%20Review%20of%20Boron%20in%20Wood%20Preservation.pdf


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