where to hit next....?

[paulc]

Worked this stone during my lunch break today-hammer stone only.  One side skinned actually pretty nicely but the second side seems to be mostly crappy cortext that refused to come off.  Now my edges are either on the good side of the stone-I don't want to remove more of that.  Or the edges are in the crumbly cortext that won't come off....help!  :-)

Paul

[paulc]

couple more....thanks.

[JackCrafty]

Heat treat it (if you haven't already) then remove the cortex side first.

Looks like you'll need to lose some width (to turn the edges toward the cortex side) before you remove the cortex flakes.

[paulc]

Thanks Pat...being me of course I didn't wait for advice.  Instead I switched to copper and beat the heck out of the stone.  Got the cortext off and had a pretty good looking preform.  It was too thick probably so I kept wacking away until it was still too thick and now too narrow to do much with...    Some day I will learn when to stop!

I did put some of the better flakes into the cooker to see if that changes how it breaks....this is texas stone I got off of ebay.  Not sure how I feel about yet.  The price was right but so far it is beyond my abilities still.

Love your videos.

Paul

[Parnell]

I'm noticing the debatage at your feet!  Looks like you've been breaking some rock!

[1442]

this would be a good strategy to get some mass off and get the margins closer to center and both sides closer together.
The red arrows are glancing type strikes to set up pretty steep platform angles.
The light blue is an isolation flake to help set up the large thinning flakes drawn  in dark blue.
Grind the platforms real heavy, then take off running, jump up in the air as high as you can and come down swinging as hard as you can while supporting the rock on your thigh with some good back edge support which should cause the flake to go all the way across, feather out clean and leave a nice biconvex surface, ready for further thinning.

[bjrogg]

So that how it's done. I'll have to give the running jump as high as I can in the air a try.  Very nice knapping lesson 1442
Bjrogg

[paulc]

That actually sounds about right 1442!  Swinging for the fences once I switched to copper....I just didn't want to admit that in front of y'all.  Here is what I have ended up with...which I still can't get thinned down....

Paul

[1442]

perfect!
Take some bevel flakes (red lines) across the base and make a good bevel about 45 degree angle.
flip it, then take some flakes ( light blue) to isolate a platform in the middle.
grind the tip and grind the platform heavy.
Next step is to support the tip by pressing firmly against an anvil of wood or stone heavy enough to resist movement and cause the channel flake to travel towards that point of contact with the tip.
Then support the base end with one finger and one thumb by squeezing in on the sides near the base.
Get your swing arm and bopper in line with the axis of the point then hit the platform with a good follow through swing like driving a nail.
repeat sequence on other side of point and WAH! LAH! Now you have a fluted point and a new addiction to fluting stuff that can not be cured.
If you have access to or could build a Solberger jig to flute with, that would make the process much easier to control all the variables associated with lining everything up and getting massive pressure applied to the platform and driving the flake down the center of the preform.
Raw Texas rock flutes really well too.

[bjrogg]

  another good lesson.
Bjrogg

[paulc]

I'll be sure to post a pic of the busted point once I try that :-)   Paul

[paulc]

See pics...the point actually mostly survived and I still have a shot at getting a hunting point out of it.  The first small flute popped on the first swing.  It didn't go very far but it worked and didn't break the point.  The other "flutes" required several shots, reflaking and regrinding and hitting again.  Amazing!

Thanks 1442!

[paulc]

What I am left with....Paul

[1442]

good job
I left out one important detail that the nipple needs to be below the surface of the preform to be fluted.
I think that's why your first flute went so short because the platform was too close to the surface. After the initial 45 deg. bevel to establish the platform angle, you can flip the point and take a pass of short flakes to get the platform closer to center and create a slight convexity for the flute to run on.
I made a sketch to show what I mean.
It causes the flute to start out thicker and travel better.

[bjrogg]

Thanks for another lesson 1442. I got a few clunkers around I'm going to have to give that a try on.
Bjrogg