View Full Version : Fire Treating Flint?

12-07-2007, 12:45 PM
When you fire treat flint what temperature does it have to be at? and is it easier to strike flakes off before or after you fire treat it? I just started knapping, anyone got any tips?

12-08-2007, 12:08 AM
Fire treating rock is tricky, but not all that hard. I have watched a few do it, but have not done it myself as I have not needed to.

Fire treating will change the make up of the rock, where when you spall a piece, it won't be grainy to the touch but rather smooth.

Mother nature does heat treating very well.

How I've seen it done. Make a fire pit, dig the bottom of the pit a little deeper than usual, put your knapping rock in it in one layer. Cover with a couple inches of dirt, then make a nice fire on top.

The fire treating I've seen is when they make a fire in the morning, let burn all day and then cool off at night.

Big no no is to throw any kind of water on the fire. You must let the rocks cool slowly and naturally.

Honestly, the arrowhead and blades that I have made out of untreated rock turned out just fine. But that's me.

Good luck,


Good site, knappers anonymous, google it.

12-08-2007, 08:16 PM
This is completely outside my experience. I understand the explanation about changing the make up of the rock. The heat would realign the molecules and all that stuff. But why do you need to heat treat in the first place? Does it make flint easier to work? More durable? I guess that's what I'm trying to understand.

That makes it more brittle, right?

12-08-2007, 10:23 PM
The heat will make a rock that is not so knappable and change it into a rock that is easy to knapp. The heat will enable the rock to be knapped easier most times.

It can make it easier to work if done properly. If not done correctly, the rock will end up with alot of fishers and cracks and become pretty brittle.

I had some rock that mother nature over heated, made a few points out of it but mostly it was trash.

12-08-2007, 10:26 PM
Thanks. That makes sense. I went out to knappers anonymous but still didn't understand the why. I appreciate your explanation.