Heat treating

[JoshinMO]

Tried heat treating some burlington at a low 300 for a couple hours yesterday, only got a light color change/hue but 400 is probably better. :dunno:
Anyway thought ht'ing would make a good topic.

[sneakygroundbuzzard]

josh, did you first heat it at around 200* for several hours to remove moisture from the rock?
i believe it needs to be heated at 400* to 450* for about 12 -24 hours
spalls are better than large chunks when it comes to heating rock
are you using a kiln or a turkey roaster to heat it?

[JoshinMO]

I brought it up slowly, was just using an oven and bowl. :blush:  :dunno:  :laugh:

[JoshinMO]

And are they supposed to stink? :huh:  :dunno:

[huntwild]

If you are married you only get one try in the oven. Yeah, they do stink, some material more than others. I di it under a fire. Kind of a fire and forget method.

[chase]

I tried heat treatment, her name was Mary When I dropped her on the stove and it burnt her she slapped me and it did not stink but it sure stung. :rolf:

[sneakygroundbuzzard]

Josh, i use a elec turkey roaster. i removed the liner pan,filled it full of fine sand.
then i dried the sand for 24 hours.
when i put in my spalls or slabs, i usually put them around the outer edge of the roaster(seems to get hotter there) an bury them under the sand. then i turn it on at 200* for 12-18  hours to remove moisture from the rock so they dont explode. then i crank it all the way up to 450* with the lid on it
the sand helps it heat up slowly,plus helps distribute the heat more evenly,then i let them soak at that temp for atleast 24 hours. then i just turn it off and let it cool down with the lid still on it for another 24 hours.
then i take out the rock,noting which piece was in which location of the pan. then check each piece for workability. if they need more heat then i put them back in and just crank it back up to 450* for another 12 hours and let it cool for another 24 hours and recheck them again

[chase]

sneakygroundbuzzard wrote:

Josh, i use a elec turkey roaster. i removed the liner pan,filled it full of fine sand.
then i dried the sand for 24 hours.
when i put in my spalls or slabs, i usually put them around the outer edge of the roaster(seems to get hotter there) an bury them under the sand. then i turn it on at 200* for 12-18  hours to remove moisture from the rock so they dont explode. then i crank it all the way up to 450* with the lid on it
the sand helps it heat up slowly,plus helps distribute the heat more evenly,then i let them soak at that temp for atleast 24 hours. then i just turn it off and let it cool down with the lid still on it for another 24 hours.
then i take out the rock,noting which piece was in which location of the pan. then check each piece for workability. if they need more heat then i put them back in and just crank it back up to 450* for another 12 hours and let it cool for another 24 hours and recheck them again

Sneaky great information Thanks man! Now thats what I am talking about.

[JoshinMO]

I think heat treating was used "before" when a lot of people suggest. Early archaic at least, and not just calf creek point's. hmy:  :laugh:   :dunno:

[painshill]

JoshinMO wrote:

I think heat treating was used "before" when a lot of people suggest. Early archaic at least, and not just calf creek point's. hmy:  :laugh:   :dunno:

  In a study of more than two thousand projectile points found at Senator Edwards Chipped Stone Workshop Site in Marion County, Florida, Barbara Purdy established that at least 750 of them had been subjected to heat treatment. The assemblage belonged to the Preceramic Archaic which dates to between 9,000 and 5,000 Before Present.
The assemblage included finished points, but also many unfinished ones in various stages of manufacture. One interesting observation was that most of the specimens showing clear signs of heat treatment on the surface had already reached a fairly advanced stage of manufacture. That led her to conclude that different kinds of projectile points may have been given heat treatment at different stages in the manufacturing process.