Author Topic: Indirect percussion Step problem  (Read 3958 times)

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Offline Sasquatch

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Indirect percussion Step problem
« on: February 11, 2015, 04:32:00 pm »
So maybe jackcrafty will read this.  I say that cause I use indirect percussion most of the time.  I learned a lot from him.  However lately I have been reducing my bifaces using a bopper.  I have noticed that when I switch over to the indirect I get lots of steps.   How do I reduce the amount of steps for that specific " Patrick" way of Knapping? You know a copper indirect tool.

Offline Zuma

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Re: Indirect percussion Step problem
« Reply #1 on: February 12, 2015, 12:12:32 am »
I know you have been around the block. I think some times I am coming around the last corner.
I think all will agree that this is a pivotal point in producing a premo point.
My thinking is that most times you transition from bigger percussion platforms to what we might
 think are adequate pressure or indirect platforms.
To me, all stone has a grain or flow some what like wood grain and with knots often.
There is to me, a delicate transition ZONE.
You are basically pre form stage and have applied some heavy bopping from the core
with the rough platforms that got you to this point.
Obviously your pre form is to fragile to withstand further indirect.
Maybe it's not. Try going further with accurate percussion.
If that does not work try stiffer platforms on your in direct or adjust your angle for a shallower flake.
BTW most ABO preforms I have studied failed with a LOP at this junction.
Good question.
Zuma
If you are a good detective the past is at your feet. The future belongs to Faith.

Offline TRACY

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Re: Indirect percussion Step problem
« Reply #2 on: February 12, 2015, 06:27:38 am »
The angle of the biface when you hit the platform is my experience. I don't do a lot of indirect but angle of blow may be something to investigate. Good luck!

Tracy
It is what it is - make the most of it!    PN500956

Offline Blitzkrieg721

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Re: Indirect percussion Step problem
« Reply #3 on: February 12, 2015, 12:41:26 pm »
I call it "Hobbit Style"..lol

I use the same method when I knapp for the most part..

It is all about the angles and the speed of the hit.. different curvatures take different angles is what I have been noticing trial and error is the only way I have improved my points..

Also different types of stone will react different to different knapping methods ..

Offline Chippintuff

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Re: Indirect percussion Step problem
« Reply #4 on: February 13, 2015, 12:28:18 pm »
In my experience the angle for indirect is much closer to 90 degrees than what is needed for direct. Come over some time and we will work on it.

WA

Offline Sasquatch

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Re: Indirect percussion Step problem
« Reply #5 on: February 13, 2015, 03:57:16 pm »
Sure WA, what about next weekend ;D.  We can have a Knappin and invite people from all over Texas.

Offline Chippintuff

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Re: Indirect percussion Step problem
« Reply #6 on: February 13, 2015, 07:32:06 pm »
That sounds like a winner. I hope we have a good crowd.

WA

Offline JackCrafty

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  • Sorry Officer, I was just gathering "materials".
Re: Indirect percussion Step problem
« Reply #7 on: February 14, 2015, 12:23:27 pm »
Hmmm.. that's funny, I never get step fractures when I transition from direct to indirect.  O:)

Seriously, an irritating step fracture right from the get-go means two things depending on the thickness of your workpiece.

If you're really good at thinning the workpiece with direct percussion (bopper) and then transition to not-so-good indirect, it's normal to encounter problems . If you're really good at both, then you may be asking too much of the stone.  It's VERY difficult to thin down a thin piece.  The most important thing is to check the surface of the workpiece.  Check it VERY carefully.  If the surface is not convex, all the way from the platform to the intended end of the flake, then you will get a step.  Flat/concave spots are very common and very difficult to knap through on thin pieces.  They may also be very difficult to see.  Try knapping with a light in front of you so you can angle the workpiece to see the shadows of the flake scars easily.

If the workpiece is still relatively thick, then beef up the platforms and knock off a couple shorter flakes to see if the step problem disappears.  If you still get steps with a stronger platform and shorter flakes, then you need a LOT more force in your strikes.  This is especially true with raw stone.  A lot of guys are surprised when I show them just how much force I use when working tough rock.  I smack it like I want to break it.
Any critter tastes good with enough butter on it.

Patrick Blank
Midland, Texas
Youtube: JackCrafty, Allergic Hobbit, Patrick Blank

Where's Rock? Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How to Cook It?  200° for 24hrs then 275° to 500° for 4hrs (depending on type), Cool for 12hr

Offline JackCrafty

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  • Sorry Officer, I was just gathering "materials".
Re: Indirect percussion Step problem
« Reply #8 on: February 14, 2015, 12:33:06 pm »
As far as what to call my style of indirect, most people are calling it the "behind-the-knee technique".  I call it "supported horizontal indirect percussion".  "Hobbit Style" makes me laugh...   ;D
« Last Edit: February 14, 2015, 04:49:23 pm by jackcrafty »
Any critter tastes good with enough butter on it.

Patrick Blank
Midland, Texas
Youtube: JackCrafty, Allergic Hobbit, Patrick Blank

Where's Rock? Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How to Cook It?  200° for 24hrs then 275° to 500° for 4hrs (depending on type), Cool for 12hr