Using ammonia to bend wood.

[Davfew]

Are any of you builders of small ships aware of a technique for bending woods like mahogany, teak, maple etc utilising liquid ammonia? It apparently plasticises the fibres of the wood so it can be easily bent to shape where it will return to its wood state staying bent.

i would be interested to hear if anyone is familiar with this technique.

cheers David

[Eddie]

Hey howya goin David mate, there is this I found a couple years ago.  

 

 

[vaddoc]

Eddie, this deserves the "doing something in the most possible complex way" award! In the end you also need a lathe and have only 5 min to thread the valve before ammonia consumes your house! 

It reminds me of this annual competition for the most purposeless scientific research.

Still, it works.

Regards

[piratepete007]

I often use household ammonia cleaner (dilute stuff) - relatively narrow PVC pipe; supported in a vertical position;  bottom end sealed and capped. Strips of timber inserted  into the tube, filled with the ammonia, cap placed over the top end, no troublesome odour. Left for approx.  5- 7 days (if not in a hurry, I aim for 2 weeks) and it works wonders. No problem at all and it DOES work.

Pete

[Canute]

The ammonia will work, but once the internal structure of the wood gets modified to bend, it doesn't actually revert back to what it was. I believe the wood structure is weaker internally after an ammonia bath. Good support under the bent wood is a must. Steam is a better bet, since the wood fibers don't get weakened.

[kurtvd19]

The use of Ammonia has been discussed here before.  Go to the link below to see my post #6, Marc's post's #7 and #16 in the thread.  Marc is a botanist and I show part of an article I wrote and gave info from a NRG Conference by -  Alex C. Wiendenhoeft of the U S Department of Agriculture Forest Services Center for Wood Anatomy Research at the Forest Products Laboratory in Madison, Wisconsin

Kurt

 

 

[bear]

Ahoy Kurt

I just took two strips out of the ammonia bottle and clamped them on the pilot house to bend to shape. They are 1/32 X 1/16"  boxwood. The only wood that I have had problems with is basswood. It has very open grain structure and turns grey throughout when ammonia is used. Works great. I soak mine from a couple of hours to 24 hours. The thinner strips around the Pilot House are 1/32 sq. swiss pear that ammonia was used on.

 

Keith

[kurtvd19]

To each his own, but I will never use ammonia and I am pretty sure that anybody who attended and heard the scientist from the Wood Products Lab at the NRG Conference will either.

Basswood is extremely easy to bed with a few minutes of soaking.

Take care,

Kurt

[MEDDO]

I don't know about anyone else but I just can't stand the smell.  There is just something about it that really turns my stomach.  After the first time I tried it out I couldn't ever use that stuff again for any reason. Kurt thanks for the explanation and link to that previous post.

[bear]

Ahoy Kurt

 

What did the scientist say about using ammonia for bending? What are the negatives  as to what it does to wood short term and long?

 

Keith

[kurtvd19]

Keith:

Go to the links I provided to see the explanation from the NRG talk as well as our MSW resident Botanist Marc.  Read the materials and if you have questions I will be happy to discuss them.  But it essentially destroys the internal wood structure.

Kurt