Primitive Archer

Main Discussion Area => Flintknapping => Topic started by: ordcorpdw on August 08, 2011, 03:35:17 pm

Title: Heat Treating Chert
Post by: ordcorpdw on August 08, 2011, 03:35:17 pm
I had read that heat treating chert would make working with it much easier. I have quite a bit. I also read warnings to not heat whole rocks as they might explode. That brought a dilemma....my samples aren't huge, palm sized at best. Spalling them makes little shards (lack of experience probably a factor) so I wanted to heat the whole rock. Is there a size that would be more likely to explode......plan on using a fire pit.
Title: Re: Heat Treating Chert
Post by: cowboy on August 08, 2011, 04:08:26 pm
In my experience. No more than an inch thick burried roughly 2 1/2" to 3" packed down and a good fire all day is all it takes.
Title: Re: Heat Treating Chert
Post by: ordcorpdw on August 08, 2011, 06:03:19 pm
sounds like a plan.....folks are gonna think Im crazy starting a blazing fire in 115 degree heat.....yay August.
Title: Re: Heat Treating Chert
Post by: cowboy on August 08, 2011, 07:06:32 pm
I hear ya. Thinner is always better and don't cook everything the first time. You'll want to practice a little till ya get it figured out. Good luck.
Title: Re: Heat Treating Chert
Post by: iowabow on August 08, 2011, 08:41:46 pm
Cowboy is correct do a smal amount and play this the time you cook.  I heat treat burlington and it take four days for the whole process. But I am cooking huges rocks. My heat work is done in a kiln. Some use a turkey cooker. The rock I have changes color and gets 100 times easier to work.
(http://i1131.photobucket.com/albums/m559/iowabow2/2011-08-04145130.jpg)
Title: Re: Heat Treating Chert
Post by: ordcorpdw on August 15, 2011, 10:32:20 pm
Heated a few of the rocks. Man what a difference. I have a 55 gal drum cut in half. Placed some of the rocks on the bottom and covered them with dirt. Burned a fire over them and left them overnight under the coals. Took them out a day later and let them cool completely......like glass!!
Title: Re: Heat Treating Chert
Post by: cowboy on August 17, 2011, 12:18:30 pm
Success! Glad to hear it! See? I weren't that hard were it ;D.
Title: Re: Heat Treating Chert
Post by: ordcorpdw on August 18, 2011, 09:49:40 pm
Nah cowboy not too bad......now if I could just get the thinning part down!
Title: Re: Heat Treating Chert
Post by: mullet on August 18, 2011, 10:25:12 pm
 I've seen Claude VanOrder bury whole rocks just a little deeper, 4-5", and then spall them till it got tough. Then bury and heat treat again. That way you end up with a bunch of long, heat treated, reducing flakes that will make points also.
Title: Re: Heat Treating Chert
Post by: cowboy on August 19, 2011, 10:35:30 am
I'll second that Eddie. I've done the same thing but not really knowing what the outcome would be. It works just that way - the rocks only heat so far in. I did learn the hard way though that you don't just build a fire on top of a big chunk of flint ::) ;D.
Title: Re: Heat Treating Chert
Post by: Tower on August 19, 2011, 10:44:17 am
I trashed lots of nice rock before I figured out how to treat in the ground. Its more hands on that's what I like about that way.