HowardM":3v9u9vnt said:
Does it have to be steamed..?
There are chemical means for bending wood, such as ammonia fed under some pressure in a sealed chamber - not something for either the professional or amateur in a standard workshop, if only because of the danger to health through possible exposure to the ammonia if something should go wrong - the kit required for ammonia bending is sophisticated and expensive. So heat via steam is the most common way of softening the lignin, which is sometimes described as the 'glue' that holds the cellulosic structure together. The steam prevents burning whilst also transferring the heat into the wood. However, it's possible to heat and bend small parts, such as stringing, getting the heat into the wood via a hot metal pipe held in a vise or similar, with a blowtorch sending a flame up the pipe around which the piece of wood is rubbed to heat it making it flexible.
Is it not the heat which is needed to get the cellulose soft.?
It's the lignin that needs to soften allowing the cells to slip past one another during the bending.
I am just thinking of how a wet part would have to be dried out before glueing.
Correct, in most cases to 20% MC or less. This is because all common wood adhesives, with the exception of polyurethane types, are formulated to work only on dry wood which, by definition, means wood at or below 20% MC. Polyurethane adhesives on the other hand work effectively on dry wood, but are actually very good for gluing up wet wood, even very wet stuff. Slainte.
