Tuesday, December 1, 2009

Making Preforms


Today the temperature was in the 50's, but it felt much warmer working in the sun.  Taking a block of mahogany obsidian, and a large hammer stone, I struck a number of flakes off.  Using an antler billet I thinned the flakes, basically making a handful of preforms.  I'll start pressure flaking them into knife blades, then haft them into antler handles.  Obsidian is formed when lava cools real fast, producing a volcanic glass in effect.  The fresh edges are extremely sharp, evidenced by the fact that I was surprised to find blood on my hands though I had not felt the cut. I am alway very careful when working with obsidian because one careless move could result in a serious laceration.  Until the final pass of pressure flaking, the edges are always ground down -  for safety and to produce a solid edge.  Trying to push a flake off of an unground sharp edge, it will simply crush and crumble.  An edge which has been properly arbraded will alllow you to build sufficient pressure against it and remove a longer flake.  I'll post updates of the progression from preform to knives as I go along.

1 comment:

Keith said...

Mark, have you ever made a crooked knife from stone?
Regards, Le Loup.