Primitive Archer

Main Discussion Area => Flintknapping => Topic started by: JackCrafty on May 17, 2011, 07:12:34 pm

Title: Heat Treating - The Light Bulb Turned On! (Updated 6-15-2011)
Post by: JackCrafty on May 17, 2011, 07:12:34 pm
Wow!  Some rock actually gets STRONGER when heat treated... in addition to being more knappable and more glossy!  Makes me wonder why I didn't start my rock cooking adventure sooner.  It's a whole different ball game now...
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: bubby on May 17, 2011, 07:30:44 pm
inlighten us Patrick, what rock have ya found that gets STRONGER when heated, or do we have to wait for the you tube premier :D
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JustinNC on May 17, 2011, 07:40:36 pm
I done run't plumb outa heat treatable rock. Gotta get some more quick. Whatd ya treat and what was the before and after like as far as "problem" and "problem solved"?
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: mullet on May 17, 2011, 11:31:28 pm
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: FlintWalker on May 17, 2011, 11:47:00 pm
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D
That's zackly whut I wuz thankin!
 I never thought of any of it getting stronger...sharper for sure though.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: nclonghunter on May 18, 2011, 01:53:17 am
Mullet, that's funny...
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JackCrafty on May 18, 2011, 02:00:09 am
Right now I'm trying to figure out what type of stone I was knapping the other night.  I just dumped a bunch of mixed flakes into the turkey roaster and let it cook overnight.  I was able to make a VERY thin edge on the stuff...felt like I was knappin' tempered glass.  It's some sort of dark grey Edwards plateau chert that I heated to 400 degrees.  I'll keep ya posted... ;D
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: criveraville on May 18, 2011, 03:34:52 am
Sounds like some of my students.. It's an experience I never tire of, watching kids have a light bulb moment and say, "Ooohhhh!!??!!!"
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JustinNC on May 18, 2011, 09:53:15 am
There ya have it. Criveraville confirmed it. The reason patrick posts nutty photos and smilies is he has the mentality of a first grader ;D.

Now patrick making THINNER points, I gotta see that!
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JustinNC on May 18, 2011, 10:34:49 am
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D
That's zackly whut I wuz thankin!
 I never thought of any of it getting stronger...sharper for sure though.

If I had some of that KY blue, I wouldn't have to entertain myself with exploding rhyolite ;)
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: criveraville on May 18, 2011, 10:35:30 am
I knew it :D
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: jonathan creason on May 18, 2011, 11:27:21 am
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D

I think that's about the only way to get this crap to break.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JustinNC on May 18, 2011, 11:47:02 am
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D

I think that's about the only way to get this crap to break.

See Eddie...i aint the only steewpud, desperate soul in NC
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: jonathan creason on May 18, 2011, 11:50:54 am
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D

I think that's about the only way to get this crap to break.

See Eddie...i aint the only steewpud, desperate soul in NC

Although I'm somewhat proud of myself for carrying that 100 lb. rock out of there, I keep wondering just why in the hell I did that.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JackCrafty on May 18, 2011, 05:36:58 pm
There ya have it. Criveraville confirmed it. The reason patrick posts nutty photos and smilies is he has the mentality of a first grader.

 ;D
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JustinNC on May 18, 2011, 06:27:15 pm
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D

I think that's about the only way to get this crap to break.

See Eddie...i aint the only steewpud, desperate soul in NC

Although I'm somewhat proud of myself for carrying that 100 lb. rock out of there, I keep wondering just why in the hell I did that.

Yeah yeah yeah....coulda just took a big arse bag and carried it out on your back.

After seeing that photo I showed you today...there IS hope in that junk.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: jonathan creason on May 18, 2011, 07:08:50 pm
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D

I think that's about the only way to get this crap to break.

See Eddie...i aint the only steewpud, desperate soul in NC

Although I'm somewhat proud of myself for carrying that 100 lb. rock out of there, I keep wondering just why in the hell I did that.

Yeah yeah yeah....coulda just took a big arse bag and carried it out on your back.

After seeing that photo I showed you today...there IS hope in that junk.

Oh, I think the rock has potential, just don't think I do.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JustinNC on May 18, 2011, 07:17:48 pm
I'd heat treat that gray Ryolite. I'd be more fun watching it blow up than beating on it. ;D

I think that's about the only way to get this crap to break.

See Eddie...i aint the only steewpud, desperate soul in NC

Although I'm somewhat proud of myself for carrying that 100 lb. rock out of there, I keep wondering just why in the hell I did that.

Yeah yeah yeah....coulda just took a big arse bag and carried it out on your back.

After seeing that photo I showed you today...there IS hope in that junk.

Oh, I think the rock has potential, just don't think I do.

Yep. You gotta be a special kinda stupid to break it just right.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: Ncsnipe on May 18, 2011, 07:59:28 pm
Aw come on now, rhyolite ain't that bad. Just because it goes from bad to good side to side and front to back and has funky folds in the way the grain runs. Well maybe you guys are right come to think of it. You know it just makes it more satisfying when you do make something out of it.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: mullet on May 19, 2011, 12:01:13 am
It'd only take a ten pound bag of charcoal to find out. >:D ;)
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: Tower on May 19, 2011, 12:07:28 am
I've a lot of grey from Richland springs Tx. Like that. Tough grainy but it knaps good when treated. Stays a little grainy but has the gloss and knaps good. Not my favorite Tx. Rock but It works.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JackCrafty on May 19, 2011, 03:02:21 am
Richland Springs?  Never been there but looks like nice country.  I think the rock I have came from the San Angelo area.  Most of the grey I have knaps fine raw but the grainy stuff cooks well.  REALLY well.  I've narrowed down the possible rock types and I should know after this weekend.
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: JackCrafty on June 01, 2011, 01:28:20 am
Well, figuring out what rock cooks best at what temperature is not as easy as it sounds... good grief!  I'm sure all you rock chefs know what I'm just now discovering.  Rock is not a consistent material.  Even though I've narrowed down the types of rock that heat well, the batches I'm cooking are all slightly different.  Sometimes the good stuff will blow up and sometimes the stuff I think won't heat well turns out fantastic.

 :-\
Title: Re: Heat Treating - The Light Bulb Turned On!
Post by: criveraville on June 01, 2011, 03:31:02 am
Sounds like you got a rock oven full of conundrums :D
Title: Re: Heat Treating - The Light Bulb Turned On! (Updated)
Post by: JackCrafty on June 15, 2011, 06:29:22 pm
OK, the heat treating experiments are beginning to show fruitful results.

First, I will offer a link for you technical types:

http://www.latrobe.edu.au/geosci/Downloads/pdfs/John%20Webb_Jan%2009/Geoarchaeology/Domanski%20et%20al%201994.pdf

In this paper the change in various properties of the stone material tested is shown on graphs.  Certain materials do increase in elasticity while decreasing in fracture toughness (leading to fantastic flaking quality).

There are some materials in my "batch" that exhibit these changes and I am trying to isolate and identify them.  At this point, they seem to be cherts that are neither dark nor light in color.  The various medium "greys" and "tans", that are not glossy to begin with, seem to work best.

On page 202, the first two paragraphs mention a separate study that basically shows that heat treatment makes the structure of the stone more uniform and orderly.  This, in turn, allows the pathways of cracks to travel with less resistance.

Clear as mud?

Me take nap now.