Regarding the use of methanol, I obviously got some significant reactions from several of you, but I was away for a couple of days and not able to keep up with this discussion.
Yes methanol must be handled with respect. I began using it mostly because I had some on the shelf from a very different project which strictly required methanol. When I learned that some furniture manufacturers were using it to bend wood, I gave it a try and liked the way it worked. I suspect that one might get similar results using ethyl alcohol which is non-toxic. Ethyl alcohol can also be ordered on-line from various sources including Amazon. I will probably give it a try when my supply of methanol gets low.
But the immediate topic is about bending planks by soaking, and whether methanol is a worthwhile alternative to water or ammonia. Methanol is wood alcohol. The stuff is toxic and very flammable. You need good ventilation, or maybe just use it outside on the "picnic table." We model builders tend to use lots of thinners and finishes that carry warnings about avoiding inhalation, ingestion, and contact with skin. Well this is definitely another one of those things. If you use rubber gloves when handling the other chemicals, you'll do the same with this stuff. However, If you don't normally use the gloves, you'll probably ignore the warnings on this label, too. So, as with everything else in our world, you gotta take responsibility for your own choices and consequences.
I put my planks and timbers in a tube with a tight fitting lid and store my working batch of methanol in the tube so I can use it multiple times, or even for several days. Besides not swelling the wood the way water does, the biggest advantage is that it completely dries in a very short amount of time. The quick drying also means that the surface of the plank is dry within seconds of pulling it out of the tube. So by the time I re-seal the tube and get ready to bend, the surface is not wet at all, just cold due to the fast evaporation. So I'm really handling a relatively dry plank by the time I'm bending it. If you must use heat, the ONLY heat I'd even consider would be an electric soldering iron or bending iron. And if it's capable of charring wood, that's too hot anyway, and might not be safe in this case. With methanol, I prefer to work cold and clamp the piece into the desired curve as fast as I can after pulling it out of the fluid. I do still leave the plank or beam clamped overnight in most cases to get a permanent result.
I'll add that there doesn't seem to be any harm to leaving planks to soak way longer than necessary - like even overnight. So you don't have to rush. If you know how long it takes to get a good result with water, the furniture manufacturers say the time will be about the same with this.
PT-2, thanks for your report of plank-bending success with isopropyl (ethyl) alcohol. I think I will order some 100% ethyl alcohol and see how that performs. It's available from Amazon as either Drinkable or as fuel grade. The latter is called Bio Ethanol. If one of you beats me to it, will you please report back with your plank-bending (not drinking) results?