knapping precut slabs

[bubby]

I disagree I always try to get all the saw marks out first pass, when I dont I mees up the pattern trying to get them out, I go all around with a notched pad both sides then I just use a pc of leather and work it down to centerline

[Ghost Knapper]

Unless the piece has some convexity to begin with multiple passes would be required to create convexity so wouldn't the flake scar pattern be determined by a later pass anyways? What caveman suggests is creating convexity in the beginning to allow for the next pass to travel farther removing the sawn surface at which point a clean flake scar pattern would be created with some convexity compared to skinning the piece on the first pass.

[vinemaplebows]

I knap like Caveman, but have seen it done the way Bubby describes.

[Chippintuff]

I have used both methods (long flakes first and also convexity first). If the piece is thin and flat to start with, I can do well covering the faces with flakes at the beginning, but there is little to no convexity there, and all the edges need is cleaning up. If the slab is thick enough to tolerate 2 or more passes of flakes, I do much better by building convexity first.

WA