Friday, 22 February 2013
Progress and Heat Bending
The stave is from a skinny log and the centre pith is clearly visible as it's roughed out. I've roughed it with bandsaw and spokeshave. I decided to use heat to take out the deflex at the outer end of the limbs and introduce a hint of reflex which will probably pull out during tillering, hopefully ending up with a fairly straight bow.
The heat will also be used to temper the belly toughening it up a bit.
Lower right shows it roughed out before the heat treatment/bending.
With small logs, as you work down towards the centre pith sometimes fine cracks will open up, they can look alarming but they are just tension in the stave releasing and they only radiate out from the centre pith and don't go down beyond it. Often you'll see them near the grip of a bow if the centre line is incorporated into grip.
The pics pretty much tell the story, in the last pic you can see the deflex in the un heated limb nearest the camera. The far limb is clamped down and has been toasted for about 45 minutes over it's outer 2/3 along the belly. It's a pretty boring task, but at least it's warm on a freezing cold day.