Hi All:
About wood bending with ammonia, I did this in 1965.
This was the first research project that I did as an undergraduate and this is what I found.
I used 28% ammonia fertilizer.
It worked well on all species of wood that I used.
There was no strain on the wood after the ammonia had gassed off from the wood. There was no tendency for the wood to return to its original condition.
I was under the impression that the lignum was softened but not removed from the wood.
I first tried to use liquid ammonia but that is another story! Lol
Finishes could be applied to the wood with no problems.
Some types of adhesives failed while others survived.
I bent the wood in various shapes and made many bow ties and bolo ties for the curious.
I understand the this method never became a commercial success as steam bending seems to be the predominant way to bend wood to this day.
I hope that this helps.
Stay well my friends,
Franchi
