So you've spent the last thirty minutes completing that nice sized biface using soft hammer percussion, only to strike it in the middle to detach one last thinning flake and "whack", the biface breaks into two parts. Frustrated, you lay down your tools and take a break - pondering the mysteries of stone. Been there - done that?

Here is a tip that may help counter these shocking events. This technique may also help diminish your failure rate for hand-held fluting of Clovis points - as explained later.

First, recognize that stone bends like rubber. When struck in the middle, it tends to bend away from the applied force and then rebounds in the opposite direction. This second reaction is what usually causes the snap break to occur. Proper holding technique goes a long way towards countering shock. So does the proper preparation of platforms, follow-through with the billet, and the correct application of force (discussed elsewhere). I assume the knapper to be somewhat accomplished at billet reduction - so will not dwell on technique other than to say that the use of good material and tools is very important and the isolation of well ground platforms is paramount. Tools must make good contact with any and all platforms. Try working off of heavily beveled edges and well ground platforms.

As for countering shock while doing soft hammer percussion, most knappers hold the objective piece in their hand - with at least one finger held just below where the flake is expected to detach. That certainly aids in better flake detachment and is well justified. Try also applying gentle finger and thumb pressure on each end of the piece (blank or biface) - in a bending motion. That should help counter shock and therefore, snap brakes, at least for shorter blanks. Better yet, try placing the objective piece on your padded leg and then apply moderate pressure on either end of the piece by using the middle finger and thumb. Strike the biface while held in this bending motion. Light pressure may also be applied to the center of the piece using the first finger. In addition to countering the shock, this bending technique also appears to improve flake detachment - resulting in thinner and larger flakes. Good luck. Please provide feedback if this technique works for you.

As for the end fluting of a biface, one need not necessarily have to isolate a platform in the classical sense. Bevel the end (convexed preferred) and grind the edge to where there are obvious platforms. Hold the objective biface against the padded leg (platform end towards the arc of the billet) using moderate finger and thumb pressure (little finger on the distant end and first finger and thumb spread near the edges of the beveled end. Make an accurate strike in the center of the beveled edge in the normal fashion. If the biface is properly thinned with a concentric central ridge, the flake should run down the face approximately one third the distance of the biface and terminate in a hinge fracture. Bevel the edge again in the opposite direction and prepare the second face for fluting. Depending on how much room is left within the concaved base, one may want to isolate a platform here, and prepare it by grinding. Hold the biface as previously described and strike off the flute flake. Final thinning of the base and grinding of the base and lateral edges completes the Clovis point. Minimum pressure flaking should be used for Clovis as most Abo work was done by percussion. There, isn't fluting just an exaggerated form of basal thinning?

One can also flute by holding the prepared biface loosely in their hand and by striking a prepared platform with a soft hammer billet. Grip the biface in a bending motion with the hand on top and the fingers and thumb underneath. This should counter the snap break. Some folks lay the biface in an open hand, strike the preform, and let it fall to the surface (in soft grass or other soft material). Don't try this with obsidian as it is very fragile and may break. Use good quality cherts.

Obviously, Abo folk had similar problems in unexpected breakage - probably considered part of the risk for knapping. Hopefully, the above tips will improve your success ratio for biface thinning and fluting. Let us know. Anyone able to flute Folsom by hand-held, direct percussion?

Doug Land
Systems Planning and Analysis, Inc.
Crystal Plaza One, Suite 801, Arlington, VA
[email protected] ph (703)413-0832
[email protected] ph (540)659-6085