Primitive Archer
Main Discussion Area => Flintknapping => Topic started by: Zuma on September 19, 2015, 05:53:41 pm
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If ya all have seen the big flake I posted for
tracker--- here is the skinny.
I was pretty sure it was Mexican black.
Didn't think it was as dry as it is.
It does not flake clean. There is always a
shatter effect with any blow or pressure flake.
It's like a mini explosion. I'll post what I have
done and welcome any advice.
1-- Rather than fill the ground somewhere with
glass I wrapped the big flake in carpet and
sheets to cradle the flake and confine the debitage.
2-- thought I had a good platform but was impatient
finding a good hammerstone. I think it was to hard
and I didn't use enough umph because of that.
Well here are a thousand words.
Zuma
Notice the jajed edges on the mini flake
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Huh. I'd just keep hitting it till I got some sharp gravel.
But maybe that was too big of bite? Doesn't seem like it tapered out at the end.
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Oh, that's just reflection huh?
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I get a lot of the POOF on mine and I think it's mini fractures from who knows. Rolling down a hill, accidental strike, maybe it dropped. Use more force. Solves everything.
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I've had unpredictable results with green/banded obsidian from south of the border as well. It's very brittle with lots of internal stress that can cause it to shatter in strange ways. I've got a batch that I spalled but I don't use it. I thinks it's at the bottom of my obsidian bucket so that's probably the reason I haven't thrown it out.
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Huh. I'd just keep hitting it till I got some sharp gravel.
But maybe that was too big of bite? Doesn't seem like it tapered out at the end.
You are right it hinged bigtime. (Poor hammerstone/power poor platform)
All products of impatience.
Patrick, thanks for the support. keeps me from being a green
obsidian orphan :'(
Zuma
Oh I did labor to get this out of the spall.
Snaped the ear with just a tiny bit of pressure??
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Well if you feel you can't handle it I'll be happy to munch it into glitter for ya >:D
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That's why I like Dacite.
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Heat it and I am not kidding
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Heck I'll try some Steve. Do you have a temperature?
Soak time? Thanks
Zuma
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No I remember reading an article from the old Fllintknappers exchange or the Tarp that was describing the same conditions and the gist of the article was that it had stresses in it and the heating relieved the stress. I would think you could go pretty high with maybe 500, take notes and let us know.
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Your gonna need a bigger roaster hehehe
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Cold weather will affect it also.
Wayne
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Well Rob, it looks like saw time.
I had the flake I took off today
do the oposite of what the last one did.
It must be a Clovis flake cuse it's
An OVERSHOT. lol >:D
Zuma
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No I remember reading an article from the old Fllintknappers exchange or the Tarp that was describing the same conditions and the gist of the article was that it had stresses in it and the heating relieved the stress. I would think you could go pretty high with maybe 500, take notes and let us know.
Well Steve,
I cranked these spalls up to 450 for a test 50 degrees every hour or so.
I let them soak an hour. Dropped back to 300 at 50 an hour.
Turned off the heat and let cool overnight.
Thanks to your advice I think I have plenty of good knapping for a long
a time to come.
The best part is getting a decent ground platform is now possible.
Still a little splintery where the spall I knapped seperated from the
mother ship.
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Nice, It has something to do with internal stress in the rock I think similar to when glass isn't annealed correctly. I think a higher temp could even be used.
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Agreed
Hope to see you with a few flakes in tow.
Thanks again :)
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Well, I got a different hammerstone (sandstone). The first one I used was quartzite.
My first spall removal with it was ok but the spall came off in two parts.
The larger piece is ok but has more curve than I would like.
Things went down hill from there. I tried a hit where the core was
not as long in the direction I was taking the spall.
Even so the spall terminated premature of what I had hoped.
(right side of first flake)
The next try was back to the right of the second spall.
I really beefed up the platform and gave It a hardy blow.
The platform just collapsed.
It's back to the drawing board for now.
Between the first go rod and the second I at least have some pretty
good material for the oven.
Zuma
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To hard of a hammer stone will split spalls
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Well, Steve,
I would'nt argue with you because both Quartzite (first hammer)
and my next best hammer (Sandstone) are pretty hard.
I think I will find a ladies bowling ball and give it a go.
Better hammer /platform contact I hope.
Zuma
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Well, Steve
I took the latest spalls and cooked
them longer and hotter. About 10 hrs overall
and a 3 hr soak. Not really much difference
for the extra energy. :-\
The upside-- nothing blew :)
Zuma
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Here is the results of a piece I knapped
of the latest batch cooked.
Not to pretty but it came from a really square
hunk. It was pleasing to knap. Just percussion.
Zuma