Deerhunter's flintknapping thread

[Deerhunter21]

Quick question. Why when im holding a rocm and i hit one side does the other side pop off? Its so annoying! I can hit one side without the other side popping off!

[Parnell]

Quick question. Why when im holding a rocm and i hit one side does the other side pop off? Its so annoying! I can hit one side without the other side popping off!

Mmm, don't understand.  Please clarify that question.  rocm?  rock?  Not sure what you mean about hitting on side but the other pops off...

[Deerhunter21]

hmm ok. So I have a rock. Im holding one side and brace it with my finger where the flake should come off. I hit the place but instead of a flake coming off where i hit it the other side of the rock breaks off and i lose probably 1/10 to 1/2 of my rock. not a flake, but a piece of my rock. the angle of the place where the piece pops off is close to 90 degrees.

[Deerhunter21]

here. normally the piece is square because im trying to zigzag edge, then it breaks off and it happens all over again. I cant get enough power with my pressure flaker to zigzag a pretty thick spall and my indirect is falling apart.

[Parnell]

Ok, I see what you are getting at. 

My initial thought is that you are holding your spall too tightly in your left hand, assuming that you are right handed.  The energy transfer from your percussion strike is well thought of as 50% from the impact and 50% from its ability to flow through the rock itself.

It is not only the ridgelines, ledges, step-fractures, etc. that keep it from being elliptical in cross section, part of the problem, but also, how you cradle the stone, where you cradle the stone, how much pressure you apply to the stone where you hold it and flinching a bit at impact...all these things will impede the flow of energy through your planned flake.

It seems that the back or broken off side, as shown in red from your drawing, was a choke point for the energy transfer and...el snapo.

Imagine the spall you are working with like holding a baby bird.  You ever hear of the Classic Rock band named .38 Special?  To quote..."Just hold on loosely, but don't let go, if you cling too tightly, your gonna lose control."

Let the force flow through you, young Jedi.

[paulc]

Is the issue simply hitting too high up on the platform?  I've done that plenty of times and had the rock crack on the opposite side.....P

[Outbackbob48]

Maybe poor support, hit one end an the other pops off from weak support Bob

[Deerhunter21]

Maybe poor support, hit one end an the other pops off from weak support Bob

I just went out and hit a couple of rocks like I normally do to look at my support. I put no support on the side that pops off but i didn't see it until i actually did it. welp! instead of making small thick flakes im back to making gravel    ! i actually see myself improving! i get longer flakes every time if even only a little bit. Its slow progress but it feels quick! im getting excited! every time i fix a mistake im getting closer to making something!

“It's an energy field created by all living things. It surrounds us and penetrates us; it binds the galaxy together.” lets break that binding force off that rock one flake at a time!

[Parnell]

That's the attitude!

[Deerhunter21]

quick question, when i apply pressure into the rock it is very hard for me to snap down to get a long flake. so instead i apply as much pressure into it that i can and slightly tilt the rock downwards until the force pushes the flake into it. it that doesn't work i put slight pressure down but i lose some of the force into it. is this ok or should i change before it becomes a habit?

[Parnell]

I don't pivot the rock so much as pivot the pressure flaker.  The thing about the plastic Ishi sticks is they flex.  That flex has a lot of snap.

I know you are having a go with indirect percussion.  I had post on that previous thread regarding your beat up tool about considering sticking with the basics of an Ishi stick and hand held pressure flaker, to start.

I would recommend this so that you can get the feel of how much pressure should be applied in different situations, with different materials, and with different techniques, etc.  There is more to learn than can simply be explained which is why you are going to need to start breaking a lot of rock.

Learn to use your your legs/inside of your thighs-knees as your power source for pressure.  Consider how sharpness/bluntness and shape of your tip can influence your work.  Have a file handy to sharpen/manipulate the tip frequently as I'm assuming you are using copper.

I recall reading something by, I think, Jackcrafty years back about active vs. passive pressure flaking.  Active being being powerful bursts of pressure to pop flakes off, whereas passive loads the pressure gradually then the flakes release on their own when the force is great enough.  Also, the idea of loading pressure gradually inward then...sort of twisting your wrist to "peel" flakes as if you were throwing a curveball.

All these things come into play.  Again, there really is simply no substitute for one on one in person time with a mentor and...BREAKING A LOT OF ROCK!!!

[Deerhunter21]

Hey so, lets say i'm at a landscape store, i see lots of rocks. how can i pick out which ones will possibly be knappable? I dont think they would let me break the rock too!

[JEB]

Look for the  rock in Parnell photo's. Who by the way gave outstanding instruction and I would love to sit in a knapping group with him. I can really use some percussion help.

[Deerhunter21]

yeah, parnell gave some dang good instructions! Thanks Parnell!

Thankyou Jeb!

[Parnell]

Thanks or the compliment, guys.  I'm always glad to be a help.

JEB, where are you at in the country? 

DH - I don't have much of an answer for your question other than to be "discreet" about testing a piece of two and then just trying to cherry pick the pieces which would work.  I really recommend getting a few bucks together and ordering some Georgetown to learn on.
It's what I really cut my teeth on.  It's uniform and easy to work but isn't too glassy.  You can see your successes and mistakes properly.