it broke

[1442]

I really failed at notching this one.
The first notch developed a crack and I chased it till it finally ran out of the notch path to where I couldn't chase it no mo. The second notch was going real well it seemed, but all of a sudden something happened and it broke.
I need to study and determine what causes cracks like this and try not to do that. 

[Outbackbob48]

1442, I broke one that is identical to yours, same material and broke on the same direction, not sure but I think my platform was  slightly above center which is a no no  with punch notching. I also punch notch just the way you showed the other day, only difference is I use a 7018 welding rod beat as thin as I can on the tip an hit it with my bopper. Let us know if ya fiqure out why it broke the way it did.  Bob

[1442]

Thanks outback,
I think that's what happened here. When Looking at thr break the flake initiation appears to be slightly above center.
I will take a pic of that this evening after work.

[ohma2]

What a shame that was a good looking piece of rock with the different colors showing .is that something different to have mixed colors in one piece?

[bjrogg]

Yep. Just like I always tell people. Still break em. Just the better you get, the nicer they look when you break them.

[1442]

ohma2
Texas rock like this usually has a thin layer right under the cortex that is usually brown like this one has.
the speckles near the tip is cortex and the brown is remnants of the thin layer. Sometimes there can be more than one layer of colors under the cortex and sometimes still a color layer may be any where in-between the two sides and vary in thickness to. Some have no color variation at all.

here's two preforms I made tonight. One had some color in the middle and the other has a cool solid brown sugar color.

color in the middle...

[1442]

solid brown sugar

[1442]

This is a picture I took after working down the first side
I like how the flake scar pattern looked there

[bronco611]

i think the reason it broke was the same reason I have had that happen. Let me get just one more flake, then I am good to go!!!!

[Bone pile]

That second one looks like sweet rock,now for a couple nachos
Bone

[sleek]

This is a picture I took after working down the first side
I like how the flake scar pattern looked there

How in the heck are you getting flakes to run so wide, long and deep?

[1442]

I like that, couple of nachos
I made another preform, thinned brown sugar some more, then pressure flaked all three.
Decided to start with color in middle preform because it was the thickest one.
It started out good but when I got to where it was too thick, it was over. I shoulda stopped.
But I didn't. It was stall city from there and I should have stopped again. But I didn't...

Sleek, all that big flake scars are a result of direct percussion with a copper bopper, heavy downward grinding and knocking heck fire maynard out of it at pretty low angles with gloved freehand support. Good rock helps a lot with how the flakes travel too.

I've been slacking on getting these things thinn enough to notch well and especially from the base. I been doing most of the work from the sides and then working the base not enough to develop a slow tapered profile.

I'll concentrate on that and hopefully have some nachos soon.

[Outbackbob48]

1442, when they start getting thicker and stall or round out have you tried  using a diamond file to get your platform right. Sometimes I can get things going again. I also noticed that if I got my angle correct on my punch notch tool and got big C flakes it helped thin ahead of notch. I also tend not to get my bases thin enough and end up in the same place. A lot of guys cringe when I get the non knapping diamond files out but if ya got a nice deep 1-1/4 notch and the other stalls at 3/4 ya need to do something, So I get the file out and get things moving again or break it trying. Bob

[1442]

Bob,
I don't have a diamond file but I would have surely used it to get the notches going again if I did.
Ima keep an eye out for one just in case this ever happens again. like next time I notch one
It's so darn fun to do deep notches,  I've got an idea to try and make something out of the ones that break like these last two did. If it works it will be a cool and unusual point type that I've seen real examples of from overseas somewhere.
I don't know the name or how to describe them so hopefully I can make one and show ya
Then hopefully I will never break another one of these and never have to wonder about what to do with a broken one again.
I'll be back!