bending veneer

judaspre1982 · Post by **judaspre1982** » Wed Apr 27, 2011 2:24 pm

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roy_okc · Post by **roy_okc** » Wed Apr 27, 2011 4:37 pm

Nice pens Farley.

horologist · Post by **horologist** » Wed Apr 27, 2011 8:02 pm

brick1 wrote:in the model airplane world, we bend and shape balsa, basswood, and spruce by soaking them in amonia. i pour some in a pan used for soaking wall paper. let it soak until the smell disappears and then bend slowly to shape. it doesn't want to go as far as you need, soak some more in a fresh batch and then bend. once its dry it wont budge from the shape you put it in. thicker needs more solution........

then when we were building a little deck out off the front door, it curved around to the door. i notched the back of a pressure treated 2 X 6 and soaked it with amonia. it bent right around without any splinters!

it has something to do with the "glue" that holds the celulose fibes together? softens it up and then when its dry the fibers are in the new shape.

take care, bill

Interesting, my experiments in bending balsa after boiling it for a while were a dismal failure, I have a nice copper box just for this purpose, purchased at a Shaker oval box making class. It works so well with cherry and maple but not at all with balsa, apparently there are woods that just don't steam bend very well.

This was to be a part of a clever design for a bridge building contest, our bridge was a disappointment as well.

Is there a degradation in the strength of the balsa after the lignin resets?

Troy

charlese · Post by **charlese** » Wed Apr 27, 2011 8:30 pm

horologist wrote: Is there a degradation in the strength of the balsa after the lignin resets?

Troy

Don't think the strength reduction is known. Lignin is truly a very complicated substance that I believe is variable between different woods. To my limited knowledge, lignin is both "glue" and a strength substance. Maybe you have looked at the wickipedia definition http://en.wikipedia.org/wiki/Lignin of lignin.

There are different chemical methods of removing lignin for making various papers as seen in this document. http://cool.conservation-us.org/byorg/abbey/ap/ap04/ap04-4/ap04-402.html I think the ammonia soak may loosen the lignin bond enough to bend but may allow for re-formation when dry.

brick1 · Post by **brick1** » Tue May 10, 2011 9:02 pm

charlese wrote:Most interesting, Bill!!! Model airplane builders are smart cookies!

Never would have thought of ammonia! Not being even a mediocre organic chemist, I wonder how ammonia will soften the "glue" and not remove it. Kinda like a paper pulping process, but not removing the glue.

"Glue" is an excellent term for lignin.

why, thank you , Chuck, i never thought i was smart.....just didn't have the funds to buy the right stuff, but i had the "guts" to figure it out, or find the right answer......take care, bill

foxtrapper · Post by **foxtrapper** » Wed May 11, 2011 7:46 am

It's not simply ammonia, it's anhydrous ammonia. That's not the same stuff you buy in the hardware store.

Couple of nice bending links. The second one focuses on the use of amhydrous ammonia.

http://www.tai-workshop.com/english/tech-2(b)-e.html

http://www.thefreelibrary.com/Anhydrous ... a020133971

pennview · Post by **pennview** » Wed May 11, 2011 12:13 pm

If you want to fool with anhydrous ammonia, take the time to read up on what safety precautions should be taken.

brick1 · Post by **brick1** » Tue May 17, 2011 8:09 pm

horologist wrote:Interesting, my experiments in bending balsa after boiling it for a while were a dismal failure, I have a nice copper box just for this purpose, purchased at a Shaker oval box making class. It works so well with cherry and maple but not at all with balsa, apparently there are woods that just don't steam bend very well.

This was to be a part of a clever design for a bridge building contest, our bridge was a disappointment as well.

Is there a degradation in the strength of the balsa after the lignin resets?

Troy

We never experienced any weakness greater than before the treatment. in fact, the rolled tube fueslage's i made were somewhat stiffer after the treatment, and the strength seemed greater, but then, i did not do any before and after test.....i do know that the weight didn't change. we used electronic gram scales to keep everything light so we could add weight where it was needed......

makanzysmith12 · Post by **makanzysmith12** » Thu May 19, 2011 2:52 pm

what I want to do is sandwich a dark veneer between a pen blank of a lighter color.

so I went to woodcraft, after trying to cut a thin piece of walnut unsuccessfully thin enough, and brought some veneer.

It's quite thin but doesn't bend enough.

I soaked it in water for about 2 hours and was going to clamp it in
between the two halfs, then when dry and shaped, I was going to glue it in place.

______________________
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horologist · Post by **horologist** » Thu May 19, 2011 10:03 pm

brick1 wrote:We never experienced any weakness greater than before the treatment. in fact, the rolled tube fueslage's i made were somewhat stiffer after the treatment, and the strength seemed greater, but then, i did not do any before and after test.....i do know that the weight didn't change. we used electronic gram scales to keep everything light so we could add weight where it was needed......

Thanks, I will have to do some testing. This contest is getting pretty competitive. I used to have some 26 baume ammonia that I bought from a blueprint supply shop to mix up a clock cleaning solution. I'm sure they are long gone now.

Troy