736 - More Heat Treat Experiments for Flintknapping

[@JohnMartin-ze8cf]

excellent video....Thanks.

[@sonoman00ify]

You Don"t put sand in the oven?

[@KnapperJackCrafty]

Noper. Never

[@G53X0Y0Z0]

I do think several of those pieces still had moisture in them. Ultimately, in my opinion, they should be dried for a much longer period. The most practical way would be to let the hot summer sun and heat do it, while they were in a place where they could be kept from absorbing any moisture. Off the ground and under shelter, but exposed to the sun and wind. Some of the rock may have had fractures already, so there would probably be no winning either way with those pieces. Uneven expansion and contraction will induce stress fractions, and I believe ensuring they were drier and a slower rise to peak temperature and back down would eliminate some of the breakage. Whether it's worth the extra time and trouble is another question.

[@KnapperJackCrafty]

I read somewhere that a small amount of moisture actually helps in the heat treating process. Water molecules have been shown to combine with minerals in the stone when heat is applied and fuses the rock mass together... similar to concrete. Just something to think about. I haven't come accross any really good research on heat treating but I have seen studies on glass and crushed-flint ceramic making in ancient Rome, for example.

[@G53X0Y0Z0]

I can't comment with any authority on the water helping to fuse the rock together. As with many things, perhaps moisture is a two edged sword, too little is less than optimum but too much is bad? I do know if there is still enough moisture inside the rock and the pressure builds high enough it will release one way or another, either through an existing passage such as a crack, or it will break the rock. The way a couple of those looked, where the rock had a shattered section, makes me think it broke from internal pressure. Of course, I could be wrong, while my experience overlaps this subject it doesn't complete encase it. Nevertheless, it's an interesting subject.

[@KnapperJackCrafty]

@@G53X0Y0Z0 yes, very interesting.

[@scottholmes8395]

Thank you again for a very informative video. I have watched just about every video you have shared and it has significantly accelerated my learning curve. Have been copying many of your points for about 9 months now. I noticed in this video you talked about matching the striking tool to the stone to minimize cracks and step fractures, any chance you could go in depth on that topic in a future video. Thanks!

[@KnapperJackCrafty]

Yeah, I could do that. I'll make a note to put "matching tool to workpiece to avoid cracks and steps" in the next lecture-style video. No joke.

[@donaldestwanick9776]

I'm glad you put this video up. Last week I baked a batch of rock wich included 3 stone's and 3 preforms of my Texas cash. The pre forms made it but the stones shattered. I think I'll throw the pieces in a tumbler to buff them up, use it as a top dressing for a potted plant maybe.

[@KnapperJackCrafty]

Good idea.

[@davidkinney7814]

Patrick : I have two land scapping cos. In my town. I have to go try some of their material and heat treat. Thanks for the demo and God Bless.

[@KnapperJackCrafty]

Hopefully they have some good stuff. That part of the country has some good rock...

[@mangothecat7309]

I have never tried knapping but would like to get into it. Where I live there is a lot of limestone quarry’s and a few river pits near by . So I am hopeful in finding some stone that I could start with any advice would be greatly appreciated. Curious on the gloves you are wearing in the video they seem perfect for the job. Could you let me know where to get or order them? Thanks.

[@KnapperJackCrafty]

I get my gloves from Lowe's or Walmart. Basically gardening gloves. Try them on first. They need to fit snugly. Oh yeah, I cover the rock-finding thing in my latest Q&A.

[@mangothecat7309]

JackCrafty thank you I will have to look for the gloves there, I have both stores in my area of eastern Ontario .

[@paulmax3185]

Patrick,This was a very informative video for me. I have not found any stone here in Oklahoma that I would treat at temps as low as 200 F . Maybe some very fine Boone chert or something,but the Ogalala quartzite or Frisco chert that the Calf Creek folks loved so much requires over 500 F and peeling off layers and several cooks to treat. Is that mostly Texas varieties you were cooking? I know it can be difficult to get you hands on good amounts or to find a source where you can harvest,but you guys certainly have a splended variety of knappable stone compared to most areas of the country. Many sites in Oklahoma have more Texas materials being used than more local stuff. Keep up the good work!

[@KnapperJackCrafty]

95% TX rock. Yes, we do have quite a variety but we also obsessively track down and collect the stuff!

[@robertbowman1419]

Jack, I wanted to know your opinion of trying to heat treat Texas flint on TOP of a wood stove? Is it worth my time? Will it even help somewhat? Thanks in advance.

[@lawrencethemain3343]

lol it'll explode. one time i had a bunch of knappable rocks in my bow fire pit heat treating, it was kind of funny they kept exploding everywhere, not enough to cut but peck ya pretty hard lol

[@lawrencethemain3343]

but maybe if slowly and at proper temp though

[@sonoman00ify]

Can I cook whole round 2"-4" round rock or does it need to be broken up?

[@KnapperJackCrafty]

It's better to break it up.

[@waruikazi]

Are your temperatures in Fahrenheit or Celsius?

[@KnapperJackCrafty]

Fahrenheit

[@shiftybroccoli8891]

Usually when its got that rusty colour, its totally unusable, as far as my experience goes.

[@KnapperJackCrafty]

Yeah, I think you're right.

[@petepeterson4540]

I always heat treat as high as it will go for 5 days have pretty good results as most of the internal flaws get exposed

[@paulswanson8189]

Do you heat treat knife river flint, and or petrified wood?

[@KnapperJackCrafty]

Knife River no, petrified wood yes. But I'm sure there will be someone out there who is aware of exceptions to this.

[@pattern1442]

You should also make sure that most of the cortex is skinned off before you heat them. That will increase your success rate since it allows more water to come out of the rock when it’s heating. Also, make sure to dry them out at around 250 for 24 hours

[@KnapperJackCrafty]

Are you a flint knapper?

[@pattern1442]

JackCrafty yeah

[@mammonihwgb5351]

The only landscape stone we have here is limestone, basalt, quartz, or jasper. The jasper knaps pretty well, a bit pricy though. What temperature do you suggest for it?

[@KnapperJackCrafty]

Try 350 degrees for the jasper. I've seen some heated as high as 500, so you might to experiment.

[@stanlindert6332]

All I’ve got is basalt here in central Washington . What do you think?.. it’s kind of grainy

[@KnapperJackCrafty]

All I can say is try it. If you can get a lot of it, it may be possible to get good at knapping it. Otherwise, if it's hard to knap, you'll only torture yourself and not make much progress.

[@stanlindert6332]

Thanks for replying back. Sometimes I hike down inside deep eroded places that cut through the wheat fields. A lot of different types of stuff from the ice age down there.

[@KnapperJackCrafty]

@@stanlindert6332 very cool.

[@bonesstones6584]

Hi Patrick, do you have any flint ridge flint from Ohio? Also, and I'm just curious here, what do you do with your debitage?

[@KnapperJackCrafty]

I think I have a few flakes of flint ridge and maybe some slabs. And I just throw the small debitage in the trash after I pick out the useable flakes.

[@currenwiggin8982]

HELP PLEASE!!!! Can I heat treat common rocks that weren’t Knappable before.

[@highplainschipper6564]

Noticed you had some buckskin down in there.Some of the buckskin tabs I got are kinda grainy.were yours grainy before heating? And did it smooth em out?

[@petepeterson4540]

why do I get enjoyment spalling and watching spalling? am I sick and deranged I like to see rocks getting broken maybe I was on a chain gang in a past life lol

[@KnapperJackCrafty]

Haha... you're not alone. Let's just leave it at that.

[@petepeterson4540]

end shock hehe

[@mammonihwgb5351]

Inspired by 1442 (the fluting guy)?

[@KnapperJackCrafty]

I know 1442. What's he up to lately? Last time I checked, he was posting a bunch of stuff over on primitive archer...

[@KnapperJackCrafty]

It seems we are getting bit by the "gravel bug" as spring approaches. He's doing some nice work with tabs and stuff, I see...

[@KnapperJackCrafty]

@@mammonihwgb5351 cool.