"Never Rot" wood for boat building

[Tourmaline]

New process for stabilizing wood from Accsys Technologies / Titan Wood:

1. How is Accoya® wood made?
The technology behind Accoya® wood is based on wood acetylation, a process that has been studied by scientists for more than 75 years and proven to be an outstanding method of improving the technical properties of wood. The process essentially alters the actual cell structure of wood by transforming free hydroxyl groups into acetyl groups. Acetyl groups simply consist of hydrogen, oxygen and carbon and are already present in all wood species (ranging from 1% to 8% by weight) and can be derived independently from acetic acid, i.e. vinegar. Thus, the process does not introduce anything to the wood that does not naturally occur in it.

2. What benefits does Accoya® wood have over unmodified wood?
Unmodified wood has ‘free hydroxyl groups’ that absorb and release water as climatic conditions change, making it prone to expansion and contraction, particularly when used outdoors (windows, doors, cladding, etc), which in turn leads to splitting and rotting.
During the Accoya® wood production process, the free hydroxyl groups within the wood are changed into acetyl groups and this reduces the ability of the wood’s cell walls to absorb water by approximately 80%, greatly improving the wood’s dimensional stability and resulting in reduced maintenance frequencies for coatings.
In addition, the change in cell structure means that fungi do not recognise Accoya® as wood and therefore do not attack it. Insects that attempt to eat the wood die of starvation because the modified structure makes it indigestible, so that it is no longer a source of food.


Accsys Technologies / Titan Wood FAQ page: http://www.accoya.com/faqs.html

[2MT]

umm as a boat builder and an eco type person who studies forests ETC.

there may be a short interval in which fungus do not recognize the treated wood as food but i assure you it will be short. three years at best in real world conditions. less in an old forest. Torados dont eat wood they bore into it. do the same to cement to. termites might die of starvation but there are a number of other things that will be happy to cut holes in the stuff for houses and as said before, "Life will find a way".

[Tourmaline]

2MT: Not certain about the softwood conversion preservation effects on Teredo Worms (termites of the seas). Additional information on the process and potential benefits from the Economist.

Jul 14th 2009
From Economist.com
Making softwoods more durable could cut demand for unsustainably logged tropical hardwoods



ONE of the reasons tropical forests are being cut down so rapidly is demand for the hardwoods, such as teak, that grow there. Hardwoods, as their name suggests, tend to be denser and more durable than softwoods. But their unsustainable logging destroys not only forests but also local creatures and the future prospects of the people who lived there.
It would be better to use softwood, which grows in cooler climes in sustainably managed forests. Softwoods are fast-growing coniferous species that account for 80% of the world’s timber. But the stuff is not durable enough to be used outdoors without being treated with toxic preservatives to protect it against fungi and insect pests. These chemicals eventually wash out into streams and rivers, and the wood must be retreated. Moreover, at the end of its life, wood that has been treated with preservatives in this way needs to be disposed of carefully.
One way out of this problem would be an environmentally friendly way of making softwood harder and more durable—something that a Norwegian company called Kebony has now achieved. It opened its first factory in January.
Kebony stops wood from rotting by placing in a vat containing a substance called furfuryl alcohol, which is made from the waste left over when sugarcane is processed. The vat is then pressurised, forcing the liquid into the wood. Next the wood is dried and heated to 110ºC. The heat transforms the liquid into a resin, which makes the cell walls of the wood thicker and stronger.
The approach is similar to that of a firm based in the Netherlands called Titan Wood. Timber swells when it is damp and shrinks when it is dry because it contains groups of atoms called hydroxyl groups, which absorb and release water. Titan Wood has developed a technique for converting hydroxyl groups into acetyl groups (a different combination of atoms) by first drying the wood in a kiln and then treating it with a chemical called acetic anhydride. The result is a wood that retains its shape in the presence of water, and is no longer recognised as wood by grubs that would otherwise attack it. It is thus extremely durable.

The products made by both companies are completely recyclable, environmentally friendly and create woods that are actually harder than most tropical hardwoods. Treated Canadian maple, for example, is harder than tropical merbau and jatoba. The strengthened softwoods can be used in everything from window frames to spas to garden furniture. Treated maple is also being adopted for decking on yachts. The cost is similar to that of teak, but the maple is more durable and easier to keep clean.
Obviously treating wood makes it more expensive. But because it does not need to receive further treatments—a shed made from treated wood would not need regular applications of creosote, for example—it should prove economical over its lifetime. Kebony reckons that its pine cladding, for example, would cost a third less than conventionally treated pine cladding over the course of 40 years. Saving money, then, need not be at the expense of helping to save the planet.

[3Psuite]

http://www.kebony.com/enu/index.cfm?page=3030&c=128

Maple boat decking, Choose yachts in the picture gallery

regards T

[ka8uet]

OK, if the treatment renders it permanenty stable, how does it biodegrade? Or does it? How does it compare in price to composite wood? What is the impact on the enviornment of producing it?

[Tourmaline]

ka8uet: Robert Rapier was the Director of Projects, Engineering, & Development for Titan Wood. Extracted from Robert Rapier's blog R Squared is the following:

"In a nutshell, Titan Wood chemically modifies fast growing softwood species like (but not limited to) Radiata pine in a way that results in their performance characteristics being superior to some of the best tropical hardwoods such as teak. It is important to note that the modification we make is at the molecular level; we do not impregnate the wood with chemical preservatives that can leach out into the environment. Wood treatment processes like Chromated Copper Arsenate (CCA) fall into this latter category. Further, disposal of treated wood can be a nightmare, as many treatment processes result in the wood being classified as hazardous waste.

Following is a brief explanation of the science behind our process, in mostly layman's terms. Wood is a very complex material, composed of many complex organic polymers (very long-chain carbon compounds). There are also numerous hydroxyl groups (OH) within wood. Think of a hydroxyl as 2/3rds of a water molecule (HOH, or H2O). Hydroxyl groups are very prone to attracting and releasing water, which is the primary mechanism by which wood shrinks and swells (and this of course makes paint crack and peel). Wood also naturally contains acetyl groups. An acetyl group is essentially an attached acetic acid molecule. Most of you are familiar with acetic acid, because you sometimes put it on your salad in the form of vinegar.

What we do in our process is remove a large fraction of those hydroxyl groups and replace them with acetyl groups. We call this wood ‘Accoya® wood’, and the properties are remarkably different than the unmodified wood we started out with. Dimensional stability, durability, and UV light resistance are all dramatically improved. Because Accoya absorbs less moisture, thermal insulating properties are also better. Further, Accoya is resistant to attack by termites, microbes, and fungi. Accoya is virtually rot-proof, and yet non-toxic.

However, I believe Titan Wood has a truly commercial carbon sequestration application. To my knowledge it is the best (only?) commercial solution in existence. Here is why I believe that.

You know that when a tree grows, it extracts carbon dioxide from the air, converts it via photosynthesis into various biopolymers, and stores the carbon as wood, leaves, etc. Left alone, a tree will uptake carbon dioxide as it grows, but it will eventually die and decompose, returning the carbon dioxide back to the atmosphere. If you could instead take the tree and just bury it deep within the earth, the carbon would be sequestered. This is in fact similar to how all of the carbon in oil, coal, and gas got sequestered in the first place. Ancient plants and animals died and were buried, and the heat and pressure of the earth turned them into fossil fuels.

Of course one can’t make money by growing trees and burying them. So, what else can you do? You could build with wood, and that also sequesters carbon during the lifetime of the application. Because Accoya is modified to resist rot, the carbon can be sequestered for much longer. That’s appealing, but it isn’t the most compelling argument. In fact, you could make that same argument about wood that is treated with toxic treatments – it can sequester carbon for a long period of time (with the obvious negative of the chemicals leeching into the environment).

No, the really compelling aspect about Accoya is that the improved characteristics make it a viable replacement for metals, plastics, and even concrete in certain applications. You can take a very fast growing tree like pine, and modify it so that it can not only replace tropical hardwoods, but it can in some instances replace the steel in a bridge. That’s where the carbon sequestration potential comes into play.

Imagine that instead of making window frames out of plastic (which comes from a fossil fuel) or aluminum (which requires a lot of electricity to produce), you made them out of Accoya. Not only have you avoided carbon emissions, but you have sequestered carbon in a long-lasting application.

Imagine that instead of constructing a bridge out of steel and concrete (both very fossil-fuel intensive), you made it out of Accoya. Again, you have avoided carbon emissions, and you have sequestered carbon. Note that neither of these scenarios is hypothetical. Accoya is currently being used in window frames, and a pair of heavy-traffic bridges is under construction right now in Sneek, the Netherlands. Kudos to the Dutch government for their foresight. The first bridge has been completed and is shown in the opening picture. (See this article for more information). Bear in mind that this bridge is certified to support 60 tons, making it the only wooden bridge in the world certified to support such a heavy load. That makes it the first of its kind."

Much, much more at Robert Rapier's blog:

http://i-r-squared.blogspot.com/sear...20Technologies

[Talbot]

I would be an interesting material for making furniture. The major downside would be the plank width, and the grain is not as nice as hardwood.

The stability would be a big plus, I would also assume that it would be less likely to get watermarked.

Would it take stain and varnishes in the same way as normal wood

What would be the impact on tools of this material

Are there any problems with the sawdust

[Tourmaline]

Talbot: From the Accoya (Titan Wood) website:

12. Does Accoya® wood have different machinability and gluability?
Accoya® wood can be machined in the same way as unmodified wood. Because, however, acetylated wood is more dimensionally stable and has lower water uptake than unmodified wood, its gluing parameters are the same as for hardwoods. Most commercially available glues can be used with Accoya® wood.

13. Can acetylated wood be glue laminated or finger-jointed?
Yes, acetylated wood can be glue laminated and finger-jointed. Wood cannot, however, be acetylated after it has been laminated or finger-jointed as the process would damage glue lines and result in de-lamination.

14. Does Accoya® wood have different paintability?
Yes. Due to the improved dimensional stability of Accoya® wood (significantly reduced swelling and shrinking), maintenance of the coating system can be increased to 10 to 15 years (3 to 5 years is the average for unmodified wood under normal circumstances). Close collaboration with Sikkens, part of the world’s leading paint company Akzo Nobel, has resulted in a package of guarantees for windows and doors, including 30 years in conjunction with the Sikkens Sentinel Plus Wood Maintenance Protection Programme. In addition, extensive tests have shown better coatings adhesion and reduced costs in applying coatings in a manufacturing environment.


NOTE: prior link to Accoya (Titan Wood) does not appear to work. Try this one.


http://www.accoya.com

[ka8uet]

Might also be good for decking. Still don't know how its price compared with composite decking, but it would be the same structurally as ordinary CCA treated wood decking, at least, I would think.

[2MT]

still not gonna jump on the boat till i see some experiments with fungi.
there are several that I can think of that would not be adverse to the transition. torado might be called the termite of the sea but it does not actually consume the wood if i recall. it tunnels through it. so i don't think it matters if the wood is treated or not.

Not downing the product i think it has a place if it lives up to the claims and so far it sounds good. i will red the site and see if its properties are good for boat building. (there are other things to stop torado and molds) just the chance that it is stable enough and inedible enough to stop most of the flora and fauna might be a thing to look at.

[Tourmaline]

Kebony is a Norwegian company also producing a 'stabilized' wood product. From the Kebony website:

Keboby decking -- the sustainable alternative to teak decking

New demands
Traditionally, the unwritten rule has been that if you want the best quality decking, you had to choose teak. But rules are made to be broken. And that is exactly what we are doing.
The new generation of shipowners is demanding sustainable wood types. That is why we invented Kebony wood, which is made of sustainable wood in an environmentally friendly process.
The result is a material that is as beautiful, durable and as stable as teak, yet stronger and practically maintenance-free.

Tested results
Kebony is a result of a process where the properties of sustainable wood are being enhanced. In this process bio-based substances are cured inside the wood. The wood becomes harder and more stable, and its durability is improved.

Kebony website: http://www.kebony.com/enu/index.cfm?page=3035&c=127

[ka8uet]

Hmmmm. All this sounds interesting. However, I can't find information on pricing, and don't know if this is available here in the states.

[David - Titan Wood]

Yes, the wood is available in the United States. Accoya from Titan Wood is sold through East Teak Hardwoods (specialist in wood for boats) and many other US distributors - http://www.accoya.com/availability.html

David

[Tabs]

I recently aquired a sample of Accoya, the sample is Radiata pine. I've ripped some thin (20mm) strips from the 75mm x 1500mm piece to carry out some epoxy bonding tests and will post the results when I destruction test them.

My first observation was that when ripping through a fairly large section like this, the colour was uniform right through the material, unlike Tanalising, Celcurising or other conventional forms of treatment, where the chemicals never seem to penetrate more than about 10mm.
The timber handled and machined like a good hardwood, smelled slightly of vinegar and produced a good finish when planed or sanded. The colour is a rather unattractive olive/grey/brown shade, so not appealing for bright finish work.
I'll give the bonds a couple of days to achieve a good cure, then let you know how they compare with untreated pine.

[David - Titan Wood]

Please let me know your results. Do you need suggestions on gluing methods and products?

Accoya is currently testing other wood species, including Beech, which will look fabulous, and have the same performance properties as Accoya Radiata Pine. It should be commercially available within a few months.

[Talbot]

I'll give the bonds a couple of days to achieve a good cure, then let you know how they compare with untreated pine.

Also be interesting how they compare with decent hardwood as well

[David - Titan Wood]

"My first observation was that when ripping through a fairly large section like this, the colour was uniform right through the material, unlike Tanalising, Celcurising or other conventional forms of treatment, where the chemicals never seem to penetrate more than about 10mm."

Yes - this is a very important observation. Accoya is 100% modified to the core. It is not a surface treatment. This gives outstanding performance in high demand applications like boating.

[Tabs]

Thanks for the offer of help David, if I need anything I'll come back to you.
We use a lot of softwood framing with ply/epoxy/glass composite building, a relatively inexpensive method of building one-off multihulls, so I'm comparing the Accoya with the standard joinery we generally use, using the same epoxy materials and techniques.
My sample is quite short so I'm unable to asses the timber's bending characteristics, my impression is that it is stiffer than untreated Radiata. Do you have any information about this and any effects on shear strength?

I find that bonds to softwood are generally better than to most hardwoods Talbot. Some hardwoods require careful surface preparation before gluing with epoxy.
If Accoya solves the expansion/contraction problem of softwoods, and bonds as well as untreated timber, one of the major longevity problems of this construction method will have been solved. A very small moisture ingress, say from an imperfectly sealed fastening, will let in a little moisture, causing the timber to expand, cracking the epoxy/glass sheathe and letting in more moisture and so on. More stable, moisture resisting, hardwoods are considerably heavier, so substituting them for softwood in a light weight multihull has more drawbacks than just the cost.

With a rot-proof timber and good epoxy resins, plywood boats might achieve the same low maintenance long life as we have come to expect with fibreglass.

[David - Titan Wood]

Please send me an email at david.bone@titanwood.com and I can send you an MOE report, etc.

[Tabs]

I destruction tested my first batch of samples today & am pleased to say that in every sample the failure was within the wood, rather than the wood epoxy interface. This was not a particularly scientific set of tests, but the butt, fillet and lap joints were typical of the bonds we make and satisfied me that the Accoya bonds as well as untreated softwood without needing any special surface preparation.