super wood

[seandepagnier]

Scientists Have Developed a Way to Make Wood as Strong as Steel https://www.sciencealert.com/new-super-wood-stronger-than-steel
Stronger Than Steel, Able to Stop a Speeding Bullet—It’s Super Wood! https://www.scientificamerican.com/article/stronger-than-steel-able-to-stop-a-speeding-bullet-mdash-it-rsquo-s-super-wood/


Boil wood in a chemical bath then steam roll it? Seems simple enough.

Can it be used for boat building?

 

[TANSL]

I wonder if working, cutting, shaping, that wood will be 10 times more difficult than doing it with natural wood. The process, then, could be to build the desired object with normal wood and subject it (the entire object) to the process described in the article. Not very practical, right?

 

[philSweet]

It's no harder to work than an equivalently strong regular wood object. Densified wood has been around for a century, just not taken to the extremes of completely collapsing all the cell structures. Delignification has been around even longer. "Blonded" wood is delignified wood, it is non corrosive and takes glue better than nontreated wood. There are lots of engineering standards covering the manufacturing and labeling and testing and approved uses of the stuff.

There are two different things going on here. One, you crush the wood cells and collapse the the hollow tube structures in the wood. This macro-compaction gets you about a three-to-one compaction and a threefold gain in strength. This has been done for ages. The second phase is to compress the three layers of polymers found in the cell walls. The inner and outer cell walls are mostly cellulose I. It's about 60% crystalized and 40% amorphous. In between is a thick layer of low density lignins and hemicelluloses that vary by species. Heat, chemistry, pressure and time conspire to crack these branched amorphous molecules and let the inner and outer cell walls collapse and fuse together. This gets you down to 20% of the original thickness and greatly improves the crystalline cellulose structure. It's no longer like a flaky pie crust.

Whether any of this makes sense from a wood-on-wood comparison is still debatable. The arguments are usually based on substituting densified wood for non-wood materials with a higher carbon footprint.

This is basically the same process as Mercerized cotton and stentered fabrics. It is a big deal with bamboo - more than 600,000 cubic meters of bamboo are densified each year. Straw can be processed to make structural panels as well.

https://www.roechling.com/us/industrial/products/composites/laminated-densified-wood
Ranprex - The Gund Company https://thegundcompany.com/ranprex

 

[Will Gilmore]

It's no harder to work than an equivalently strong regular wood object.

Does this mean the same tools you would need to work lignum vitae with the same expected wear on the blades? Given a similar density?

This macro-compaction gets you about a three-to-one compaction and a threefold gain in strength.

In what ways is the denser wood stronger? I can see it being less compressible, and stiffer. Does it have greater shear strength and more tensile strength? Is that a by weight or by dimension comparison?

 

[seandepagnier]

My understanding anyway is that it is 11 times stronger and only 3-4 times more dense because of chemical changes not just compression. Also removing parts of the wood that do not add to strength. Is this possible?

 

[philSweet]

I haven't really seen an apples to apples comparison, but I assume it's the weaker stress directions that get the largest benefits and the material becomes more isotropic. This allows a thicker lamina design for plywood layups. But you have to carefully look at the costs of taking the process to different degrees. After all, you can basically convert a tree to Rayon if you work hard enough. But making Rayon out of crude oil (pre cooked and squeezed trees) is easier.

 

[Howlandwoodworks]

Hot molded veneer plywood was used in the mid 20th century and was replaced with fiberglass process that most small shops could do with a lot of expensive equipment. A large autoclave would not be something that would be cost effect.
I have a 1954 Jet 14 Class sailboat that has a hot molded mahogany hull that I saved from the chainsaw. It is not as hard as steel but it just doesn't rot or delaminate. The shell is about a 1/4" thick and there are no ribs, I assume because of it's size. It does have a keelson that hold the two halves of the hull together.

Here are some hot molded Peanut Shell Prams that are also from the same time period.

firefly race ing dingy - Google Search https://www.google.com/search?q=firefly+race+ing+dingy&oq=firefly+race+ing+dingy&aqs=chrome..69i57j0i22i30i625.16472j0j7&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:ae4abe97,vid:X6hgRQuvg60

 

[philSweet]

I also helped rescue a '54 Luders Jet 14 down in the Florida Keys. Three guys had found it in a yard sale and brought it to me. They wanted to get it on the water for $50. I spent about two weeks of spare time working on it because I couldn't bare the thought of those mutts mopping on a couple gallons of polyester and ruining it.