Ammonia to make wood flexible?

[Brian Kent]

Has anyone here tried using ammonia to "plasticize" wood? In this case not meaning impregnating the wood with plastic, but making the wood bendable.

A friend told me about this and it looked fascinating. Here is an article that describes it:

http://pubs.acs <dot> org/doi/abs/10.1021/ie50646a004?journalCode=iechad

It would be worth an experiment to see if:
1) it works
2) it changes the color of the wood dramatically
3) if it affects the ability to glue-laminate strips together when they dry.

It might be an alternative to steam bending. Worth an experment.

[Alan Hick]

Haven't done it. I've watched videos about it, and decided that steam boxes and bent laminations were good enough for me.

https://youtu.be/9Z0SsAyHKzc
https://youtu.be/7XqX3Dxj__4

[Morey St. Denis]

Sounds interesting! Have you got access to the rest of that technical literature, details proposed and tested in application with wood?.. Chemically speaking, Ammonia is NH^3 and is gaseous in the range of atmospheric pressure and tens of degrees sub-zero temperatures. Within hermetically sealed fluid mechanical circuits, it functions as a refrigerant of unequaled efficiency. The Space Shuttle and International Space Station use(d) anhydrous ammonia exclusively as the working fluid for all temperature equilibration, thermal energy distribution and HVAC functions on orbit. What most people encounter as "ammonia" is actually Ammonium Hydroxide (NH^4-OH) or dilute concentrations of less than 10% Ammonia dissolved in water. For industrial processing, it can be obtained in liquid concentrations not exceeding 30%, but always remains highly caustic, toxic on inhalation and dermal exposure, and very hazardous to handle due high vapor pressure at room temperatures. How might these properties be managed usefully in a woodworking hobbyist environment?

I also know for fact and experience that ammonia will cause dramatic darkening of all woods possessing any appreciable tannin content. Ever hear of the "fuming" process using vapor tents and "household" ammonium hydroxide to darken White Oaks, particularly common during the "Craftsman" style movement? Does this rendering of coffee hued or "blackened" ammonia treated lumber cause any inconvenience or stylistic considerations? Lets hear more about the proposed process, specialized equipment, and handling procedures, for a new category of pressure treated, glue-laminated woods... If this article perhaps proposed, confused or misused the technical compound Ammonia for more common Ammonium Hydroxide, the liquid form you'd be working with is 90% water solution with just a fraction of dissolved odorous and caustic reducing ammonia. As you'd heat it to make wood lignins conventionally more pliable, you'd boil off the ammonia as concentrated vapor, except within a pressurized vessel. As hot wood was withdrawn to bend at atmospheric, seems the ammonia component may likely preferentially flash-off...

[Brian Kent]

I have the same questions and no answers. The link is all I know.

[Morey St. Denis]

I read that link as a quick abstract to a potentially useful technical publication. Further details available by subscription or one-time access for a fee of $35. Thought perhaps the fellow who makes this association and comes across that tempting notice may well already be a subscriber to "Industrial & Engineering Chemistry" publications...

Anyone out there with an existing subscription to "ELSEVIER Knovel" services? Likely also searchable through that technical information service as well...

[Bob Vavricka]

In another life when I was teaching industrial arts in western Kansas, 1971-90 there was an industrial arts teacher in the area who worked with a student to make a bent wood rocker using anhydrous ammonia to bend the wood. I believe they set up the equipment at his farm because of the danger of working with anhydrous ammonia. As I understood it the ammonia broke down the bond of the lignin in the wood allowing it to easily be bent into shape. They described it as being like a wet noodle. As the ammonia dissipated new bonds were set up with the lignin and it resisted being unbent as much as it resisted being bent in the first place. This is from memory so I may not have it all right. I'll see if I can find more information on the process.

[Mel Fulks]

I first read about it in a 1957 encyclopedia ...which was pretty new. Never heard of using it outside a factory. I think most problems with steaming wood are caused by using too dry wood. I've read about windsor chair makers cutting their own chair wood ,then demoting it to fire wood once it air dries too much.

[Lon Crosby]

https://books.google.com/books?id=VrENESuik3cC&pg=PA15&lpg=PA15&dq=plasticizing+wood+with+liquid+ammonia&source=bl&ots=nRFh-XCDk0&sig=CaUnx0DycBAd1epHZYc6AB3ek0I&hl=en&sa=X&ved=0CCMQ6AEwADgKahUKEwiC7v3-qubHAhUHFJIKHe8MAWU#v=onepage&q=plasticizing%20wood%20with%20liquid%20ammonia&f=false You want page 15.

Also do a Google search - including patents.

[Kevin Jenness]

Another approach- pre compressed wood: http://www.puretimber.com/