Thinning a spall frustration

[GooseGossett]

I'm doing my best to thin out some spalls and I'm learning real quick that I need to be more accurate with my bopper hits.  I tend to cause major frustration in missing a platform I spend 2 minutes setting up.  I'm also getting some angle issues with overshots when I want the flake to terminate.  I guess it goes with breaking rock.  I did however do some indirect percussion with my ishi stick (I think it's jackcrafty here but allergichobbit on youtube thanks for all of those videos) I'm loving the flakes I'm getting doing indirect.  I seem to be getting deeper and longer flakes.  I would say overall that I need to work my angles and my accuracy... or just quit hitting the stuff that doesn't need to be on the point/knife and leave the necessary rock intact.  Simple enough eh?

I'm also learning that obsidian will be the bain of my existence!  The pile of obsidian trash was a spall and with the junk I was hitting or missing it all ended up in the pile.  So thank you so much Timo for the rock last week it's serving me well.

[gstoneberg]

I understand too well.  I struggle more with undershoots than overshoots, but it is a challenge to learn to do what the pros do so effortlessly.  I also find obsidian frustrating.  It knapps easier than flint but it cuts me soooo bad every time I try it.  Pretty rock though.

I think we just have to keep plugging.  Doesn't seem that we can get around the dues in rubble this hobby requires. 

Good luck,
George

[iowabow]

The short flakes that have steps are because you are- A hitting to soft, B do not have convexity. There are other reasons but these are two basic areas you can easily focus on. If the flake you want to remove is  just straight or even worse if it has a dip in it then it will most likely step. The better you get the more you will know what will work but for now try hitting only good platforms that have good convexity. Convexity is the amount of curve on the flake you want to remove. You want the flake to be strong when it is releasing so an arch of stone is stronger than a flat line of stone and a dip is the reverse of an arch and twice as weak.  Good luck and hope this helps. BTW what you learn now applies to pressure flaking "good convexity is the key" Now if you do not have the convexity then create it.  You will figure out how.

[Hardawaypoints]

You could also be hitting too straight in on the biface and not down enough.  It would be easier to show you than explain it.  Early on, I got some serious hinges that lead to steps from hitting too straight in and the only way to rescue the point was to come at it from the other side of the blank in hopes of running a flake under the hinge/ step.

Hope this helps.

Jim