Cooking up some rock

[budmenchaca]

Hello all,
I currently have a mini-fire pit that's been burning hot all day. I have some burlington chert an some tough grainy flint (not sure of the official name) I just know it does a number on my billets.

It's not very big but it's my first attempt and I'm pretty stoked about it.

It's been going for about 7 hrs now. Here are some pics:










This last one was taken about 20 minutes ago.

When the time comes to assess the damage...I'll post more pics.

[cowboy]

Mmm, i can almost smell em from here. Aught to be getting close to done . One of three things will come out of that: no change, bunch of blown up shards, or slicked up new and improved rocks . I'm thinking the latter.

[Will H]

How did them rocks turn out?

[budmenchaca]

I haven't had a minute to pull all of them out but the few that I did take out looked no different. 

I heat treated two types: A whitish, chalky burlington chert and a darker, unidentified tough Texas flint. I think the lighter stuff just needed more heat (or time?)...

I could see where the burlington started to change around the edges and in a few random spots but I guess next time I'll have to get that fire burning hotter and longer.

The darker stuff, or at least the 3 small pieces I managed to pull out yesterday looked a lot different. The surface of the rock looks glossy but I think that a bit more heat and time would have worked wonders on the stuff - it looks like the colors were starting to come out.

I haven't had a chance to beat on any of the rock just yet to see how it works but as soon as I get a minute, I'll post some pics of the treated rock. (I'm eager to test that dark stuff...as it was tougher than nails before I cooked it up.)

Anyhow, thanks for checking it out!

- - more pics to come - -

[cowboy]

Can't wait. Come to think of it that darker stuff generally responds better to heat than the lighter, tx stuff anyway. You won't be able to tell if there's any difference until you start hitting it - not much change to the outside visually but slick on the inside.

[budmenchaca]

We had some rain yesterday so I couldn't get into the pit to check on the rocks I cooked a couple of days ago.

This afternoon, I'll be busy getting the yard back in order...ugh! (Threw a b-day party for my daughter this weekend). A yard full of screaming 8 yr old girls can tear up a yard faster that I can break a biface!

What's bad is I can hear the rock calling my name. It's begging to be turned into something!

Anyhow, I just wanted to post an update!

Thanks for stopping back by!

[chertle]

Can't wait to see em.  I hope it worked out really well for you

[budmenchaca]

I had a bit of free time yesterday after work so I tried banging on some of this cooked rock. I chipped out this ugly, crude triangle point out of the tough grainy stuff but my notches stalled.  (still learning)



Front and back views of birdpoint  - tough unidentified, grainy chert.

(I had to scan these images in with my desktop scanner - my camera is unavailable at the moment.)

The Burlington didn't turn out any different than when I put it into the ground. Both types of flint didn't change much with the exception of a couple of darker pieces.

I guess next time I'll have to turn up the heat and maybe leave on for more than 8 hours...?

I also heard that packing the sand helps also...better conductor of heat or something.

I didn't post any pics of the stone as it produced no tangible results. So I believe it will be back to the drawing board for me.

Thanks for checking this out and as always I welcome any comments, suggestions or tips - This young grasshoppa has much to learn 

[Stringman]

Bud, I failed for a long time before I startd noticing any change. What I learned was if you put the spalls too deep they wont get any heat. Second, start a slow fire on them for 4-6 hours before you begin building heat. That gives them a chance to dry. Keep in mind some may need more drying time. If yyou started the fire early in the morning, then by 2pm I start puttin a real fire on it. Use oak or blqck locust or *gasp* hedge to build super hot coals. Keep this up till 10p, or whenever ur bedtime is, then build it up  plenty high and go to bed. Let it cool for a fullday before you dig it up.. If you buried more than one layer deep you might notice a difference between the layers. Note that and adjust.

My best attempts were when there was only about 2" of sand over the spalls. Hope this helps!
Scott

[budmenchaca]

Thanks Scott, that definitely helps.

I may try again soon and you've mentioned some stuff I haven't heard before. (Noted  )

There's lots of information on the web but nothing compares to the kind of knowledge shared on this forum - specific and detailed!

Thanks again!

[Stringman]

Nother thing I forgot to mention....

Don't try to cook rock when the ground is wet cause it will either pop the rock or not get hot enough.

Scott