heat treating flint

[iowabow]

Another photo of the pit

[iowabow]

See how the pit has changed?

[iowabow]

The very edge read 130

[iowabow]

I really don't know if this is in the hottest spot but we still have a fire burning after 48 hours here. So with this type of heat treating you will get days of work from the process and a very slow ramp down.

[iowabow]

Look closely at the earlier pit photo and the latest. You will notice the surface has sunken. The charcoal created during the firing process is being consumed at a very slow rate.

[nclonghunter]

Cant wait to see the end results. I havent heated any rock before, is there a visual difference or only a workable difference?

I know some will change colors but I am asking about the texture or grain appearance?

[iowabow]

Yes it slicks it up a lot and makes it flake better.

[Tower]

Nothing like good ole down home cookin!!!! Can't wait to see outcome.   

[iowabow]

The weather is moving in time to cover the pit.

[iowabow]

I went out and heat was still coming from the surface so I covered the pit  with scrap wood. I think a shelter of hide would have worked well back in the day.

[iowabow]

Keeping my hands out of the pit is really hard to to do. I really want to review the results but my past data tells me that the heat is still doing work.

[iowabow]

Nothing like good ole down home cookin!!!! Can't wait to see outcome.

I keep changing the cook parameters to learn from each firing. This time I soaked a large biface in water for a week to see if it will crack and placed it in the center with wet sand above and below it. Yes this seems crazy but the water can only reach 212 degrees and until the water is gone this should slow the climb in temp in the chert bed. I changed the soaking of logs to the soaking of sand. My past research shows a slower ramp with the addition of water to the bottom of the fire.

[iowabow]

The pit was arranged with larges bifaces to the middle and spalls and flakes to the outside. I can't remember how many bifaces were in the pit but they are long so if they crack we should still have some nice material to work with anyway. My goal is to have one nice paleo blade for the display I am working on. I think 6-8 are in the pit. I guessed a couple could crack and I would break a couple and maybe get a good one. Big points are hard to come by. First you have to find quality and size. This is difficult when out crops are the source material and contain ice cracking. Then you have to have some luck and hammer stone cortex without causing freeze cracks to expand. Then you have to working. It to a biface without snapping it from a bad hit. If you make it this far then it must survive the heat treating. If the heat is ok ,not to brittle and not too under cooked then it might flake well if there are no imperfections in the stone. So the road is long for large blades.

[iowabow]

With pit still warm and a 2 inch rain fall predicted I pulled the spalls and befaces. I washed them so we can get a better idea of the out come. As you look at the stone remember that it came from a number of different quarries so there is going to be a lot of variations. Not one price broke. I am sure I am happy with the results till I start hitting the stone.

[iowabow]

Here is an example where you could predict that it might need some more heat. I really Am not sure with this Vein because I have only recently started working this material. My best guess it to throw it into the next pit fire and see if we get better color.