Primitive Archer

Main Discussion Area => Flintknapping => Topic started by: Young Bowyer on June 01, 2011, 08:23:01 pm

Title: Heat treating?
Post by: Young Bowyer on June 01, 2011, 08:23:01 pm
Hi, new to flintknapping,  :) so i was wondering what are the advantages of heatreated rock as opposed to nontreated rock, e.g hardness ect.
Title: Re: Heat treating?
Post by: Tower on June 01, 2011, 08:54:22 pm
Heat treating some materials weakens the molecular bond & makes the stone easier to knap. But it is not true for all stones & the temp differs from stone to stone.
Title: Re: Heat treating?
Post by: Young Bowyer on June 01, 2011, 08:57:18 pm
ah i see thanks  :)
Title: Re: Heat treating?
Post by: cowboy on June 02, 2011, 12:08:13 pm
Think of it as making glass from silica sand. Different cherts have differing amount of silica content. Heating just slicks them up. But as Tower said it doesn't work on all rocks..
Title: Re: Heat treating?
Post by: JackCrafty on June 02, 2011, 01:57:56 pm
I've been researching heat treating recently and it seems that the heat "lines up" the molecules and allows fractures to travel through the stone more easily.  I don't think it necessarily makes the stone weaker, although it seems that way because it becomes more brittle.  The stone becomes glass-like.

I'm treating ALL my stone that responds to heat.  There are drawbacks, though.  I've got to learn how to knap this "new" material and it's frustrating.  I'm braking a lot more points during the preform stage.  It is, however, easier to notch and easier to work with abo tools like antler and bone flakers.
Title: Re: Heat treating?
Post by: JustinNC on June 02, 2011, 02:05:31 pm
I've been researching heat treating recently and it seems that the heat "lines up" the molecules and allows fractures to travel through the stone more easily.  I don't think it necessarily makes the stone weaker, although it seems that way because it becomes more brittle.  The stone becomes glass-like.

I'm treating ALL my stone that responds to heat.  There are drawbacks, though.  I've got to learn how to knap this "new" material and it's frustrating.  I'm braking a lot more points during the preform stage.  It is, however, easier to notch and easier to work with abo tools like antler and bone flakers.

In your opinion, how many artifacts were from heat treated material?
Title: Re: Heat treating?
Post by: JackCrafty on June 02, 2011, 02:07:23 pm
From the collections I've seen out here in West Texas, it looks like 90% of the material was heat treated.
Title: Re: Heat treating?
Post by: JustinNC on June 02, 2011, 03:25:42 pm
From the collections I've seen out here in West Texas, it looks like 90% of the material was heat treated.

Doesnt make me feel as bad about sticking a fire over top of some now :)
Title: Re: Heat treating?
Post by: Tower on June 02, 2011, 05:52:01 pm
I read in Europe they have found evidence of heat treating as far back as 15000-20000 ago. I have numerous points from the TX. hill country that have been treated.
Title: Re: Heat treating?
Post by: Young Bowyer on June 02, 2011, 06:42:42 pm
How would you heat treat rock? Just throw it in the coals?  :P
Title: Re: Heat treating?
Post by: sailordad on June 02, 2011, 09:07:28 pm
How would you heat treat rock? Just throw it in the coals?  :P

yup go get the prettiest rock you can find,regardless of the cost and give that a try
stand there and watch it untill its finished
and let us know how that went for ya  ;D


actaully i use a electric turkey roaster filled with sand
Title: Re: Heat treating?
Post by: Young Bowyer on June 02, 2011, 09:11:18 pm
well what do you do in turkey season?  ;D anyways ill try some obsidian im gonna get from 3 rivers archery
Title: Re: Heat treating?
Post by: sailordad on June 02, 2011, 09:13:48 pm
we either cook our birds on the grill or the oven in the kitchen

no need to heat obsidion as mother nature has already done it for you
its volcanic glass  ;)

Title: Re: Heat treating?
Post by: Young Bowyer on June 04, 2011, 12:42:18 am
oh flint or chert, novaculite are what i hsould use?  :)
Title: Re: Heat treating?
Post by: JustinNC on June 04, 2011, 01:21:42 am
oh flint or chert, novaculite are what i hsould use?  :)

Novaculite heats at too high a temp for a roaster.
Title: Re: Heat treating?
Post by: Young Bowyer on June 04, 2011, 01:46:00 am
Oh okay thanks
Title: Re: Heat treating?
Post by: cowboy on June 04, 2011, 11:41:44 am
To cook chert you wanna work them down a little first to where there no more than around an inch thick or thinner. Bury them in sandy dirt about three inches, walk it down firm then build a fire on top for the better part of a day. Let that cool off for a couple days and voila!
Title: Re: Heat treating?
Post by: Young Bowyer on June 04, 2011, 01:15:43 pm
Ooh, very interesting stuff here, thanks for the tutorial cowboy  :)