In the picture below I (left) am holding the best spall I knocked off. After we finished with the big rock, we both worked on smaller pieces.
I continued the work on my piece last night. I was pretty happy with the overall shape of the piece. I had a good center line and the piece was pretty symmetrical. There was however a stack of mass I wanted to remove. There were step fractures protecting the stack from three sides so I had one angle to attack from.
I was worried that if I didn't push hard enough, I would make another step fracture and then I'd be totally screwed so I pushed really hard. It turns out that I pushed too hard and flaked all the way across the point and up towards the tip.
In the picture below, the flake was pushed from the bottom left to the middle right. The path of the flake is the glossy area. Also notice how the stone is convex on the upper right. This was concave before I took the flake.
What I learned:
- First experience with antler and stone billets and an ishi stick
- Be more aggressive with thinning during percussion flaking. Strike harder than I'm used to.
- Got the feel for how much pressure is need to take the flake I want with out leaving a stack (too little pressure) or overshooting (too much pressure).