Primitive Archer

Main Discussion Area => Flintknapping => Topic started by: Bryce H on July 21, 2011, 08:35:30 pm

Title: Heating rock?
Post by: Bryce H on July 21, 2011, 08:35:30 pm
I have yet to even so much as attempt at making a point as of yet, but I came into possession of a couple pieces of flint the other day. I was wondering if the rock could be heat treated in an oven at home, as I live in apartments and can't build a fire outside (not that I could anyway, with the miserable burn bans all 'cross Texas). If I can, what temp and how long should I do it for? Thanks!


Bryce
Title: Re: Heating rock?
Post by: seabass on July 21, 2011, 11:17:19 pm
i am in the same boat as you are.one guy told me to get a turkey roaster.put sand in the bottom,then the rock.cover the rock with more sand,then set the roaster on 450 and let it bake for 8 to ten hours.then the guy got some more info from jackcrafty.i have it somewhere.when i find it i will post it.we all know jackcrafty knows his rock.let me go find it and i will post it.
Title: Re: Heating rock?
Post by: mullet on July 21, 2011, 11:21:14 pm
 I use a small black and Decker toaster oven, no sand. I spall small pieces, crank it to 450 when I get ready for bed and unplug it in the morning. If you try big pieces they will blow up like a small bomb, not good for your main oven. ::)
Title: Re: Heating rock?
Post by: Bryce H on July 21, 2011, 11:47:34 pm
If the oven explodes, I'll think it lucky after the lady gets 'hold of me.  ;)

Thanks guys; I'll be interested in reading that, seabass.
Title: Re: Heating rock?
Post by: seabass on July 21, 2011, 11:53:44 pm
i am having trouble finding it.i got the info from criveraville.i'll get a hold of him and try to get him to post it.mullet,thanks for the info.i am tring to learn this stuff also.thanks,steve
Title: Re: Heating rock?
Post by: Timo on July 22, 2011, 01:04:01 am
I used a roaster for a good bit until I made me some kilns. The roaster worked pretty well for lower temp stuff, but will not get some rock to the correct temp to help it any.

Bed your rock in some sand, and just stack it in there putting your best pieces along the bottom and sides as most roasters have their elements there. Then just pour sand in and around all the rock  until it's full. Crack the lid and run it on 200 degrees for at least 24 hrs, this will dry the rock and help to prevent any blowups. Set the lid and raise the temp in intervals until you reach the high settings. ( most ovens only get about 450).Let it cook for 8 hrs. Shut it off and let it cool down well. Don't open until you think it is well cooled.
Title: Re: Heating rock?
Post by: criveraville on July 22, 2011, 04:00:59 am
Steve, 

Here is how Patrick cooks his rock.  

Heating makes a lot of difference in some rocks.  Dry the rocks in a taster oven at 250 degrees for a few days.   Then heat to 350 degrees for a few hours and then let it cool down.  Take a few flakes off to see if it's glossier than before.  Discard cracked pieces.  If they all crack, the rock cannot be heat treated.  If the rock is a little glossy, then heat at 450 degrees for a few hours then let it cool down.  Takes a few flakes off.  If it's glossy and not too brittle, you're good to go.  If it cracks or doesn't get really glossy, then you probably don't want to heat treat at 450 degrees.  You can experiment with higher heat, but I recommend only heating to 350 or 450 and using the rock that responds well at these temperatures.

This only a suggestion.  I'm not an expert in heat treating, by any means. 
Title: Re: Heating rock?
Post by: Tower on July 22, 2011, 09:51:04 am
Hey Bryce , what part of TX. Are you from.
Title: Re: Heating rock?
Post by: Bryce H on July 23, 2011, 10:20:09 am
Appreciate the input guys, thanks.

Tower, I live between Ft. Worth and Dallas in Euless. Moved down from Oklahoma last year, and I love every bit of it.
Title: Re: Heating rock?
Post by: mullet on July 23, 2011, 12:57:37 pm
Search a few pages back in this section, I posted a series of pictures, heat treating with charcoal.
Title: Re: Heating rock?
Post by: gstoneberg on July 23, 2011, 02:00:45 pm
Hey Bryce, drive on over to this side of Dallas.  I've got some heat treated rock I'll share with you.  I can show you how to turn a perfectly good spall into a turtle, or a marble.  I've also perfected knocking the points off points, and I'd be happy to demonstrate any of those skills.  Patrick described his heating technique to me as well and one of his latest youtube videos shows his rock in an electric roaster. 

Any time, shoot on over here and we'll break up some rock together.  We can also build a bow if you want, at least I'm not a newbie at that.

George