Heat Treating Chert

[ordcorpdw]

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.

[cowboy]

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.

[ordcorpdw]

sounds like a plan.....folks are gonna think Im crazy starting a blazing fire in 115 degree heat.....yay August.

[cowboy]

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.

[iowabow]

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.

[ordcorpdw]

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!!

[cowboy]

Success! Glad to hear it! See? I weren't that hard were it .

[ordcorpdw]

Nah cowboy not too bad......now if I could just get the thinning part down!

[mullet]

 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.

[cowboy]

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 .

[Tower]

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.