Author Topic: Having issues knapping chert (Read 5466 times)

m1garand_man · « **on:** March 21, 2018, 06:33:45 PM »

I have access to an abundance of chert rocks from roadbed in this part of Texas and while I have gotten some chips off that will spark I am having problems getting good blades or even forming a core. These rocks are not nodules but rather fragments of what seem to be big slabs of the stuff from the area.

I have watched some good videos on youtube on the topic but the issue I keep running into is difficulty in getting the chert to fracture in a predictable way.

I have read arguments for and against heat trating the rock before knapping and need to test this process myself. I do not know the temp and duration for the heat treatment though.

Beyond that I would appreciate any reccomend at ions or advice you have to offer on the topic of knapping chert for long rifles.

Hungry Horse · « **Reply #1 on:** March 21, 2018, 06:42:38 PM »

Wear safety glasses, and a dust mask. Make sure the glasses contact your cheek at the bottom. A regular paper dust mask will be fine. All it has to do is keep you from breathing in partcles of razor sharp stone.
There are a lot of videos of people napping arrowheads, but not very many demonstrating napping gun flints. There are a couple of books that demonstrate gun flint manufacture, but I don’t remember the titles.

Hungry Horse

Tim Ault · « **Reply #2 on:** March 21, 2018, 06:50:01 PM »

I went down this road last winter , a member on another forum sent we some chunks of chert believe from Tex/ark. Border area came from a RR rail bed said the stuff is everywhere just laying there . Chunks I got were golfball -tennis ball size had a heck of a time getting it to fracture where I wanted still got some pieces that loosely resemble a gun flint out of it and they worked fine just didn't look like the ones I paid 2 bucks a piece for ,I also ask about heat treating and all the replies were for gun flints no don't do it . Oh yea wear a thick glove in your holding hand ! I shed a good amount of blood early on before I knew those shard are like a razor blade

D. Taylor Sapergia · « **Reply #3 on:** March 21, 2018, 07:18:44 PM »

If you are trying to make gun flints, definitely do not heat treat the stone. It will become glassy looking, and flake easier, but that makes a poor gunflint. To create spauls or blades, you need a faily large bolder; a tenis ball sized rock is difficult to remove a spaul. Use a granite hammer stone, or a heavy copper bopper to strike the bolder. Pick a spot on the rock that has a sharp angled edge, LESS THE NINETY DEGREES! Strike the bolder with the hammer stone or bopper back from the edge about 3/8". The flake will come off the bolder at 135 degrees from the impact line/angle, so set up your strike angle to accommodate that, and you will remove blades. I assume your chert is clear, fine grained, and without inclusions. Is it white?

m1garand_man · « **Reply #4 on:** March 21, 2018, 08:18:47 PM »

My first test rock was the biggest one I could find and that was a soft ball size piece.

Almost all the edges on it are 90* or greater so that may be a problem. It is a tan colored rock that's tight grained but has inclusions and previews fractures on it too which are causing problems.

My bobber is a large brass drift punch that weighs about 2.5 pounds. I will possibly round the end of it off into a semi sphere now that I know these rocks spark.

WadePatton · « **Reply #5 on:** March 21, 2018, 11:38:20 PM »

Paleo Man Jim is a great source of free knapping instruction on youtube. Although he only really teaches tool knapping, I'm fairly confident one could make gunflints after learning the basics from Jim.

Personally started to try, as there is no rock on my ridge that doesn't spark when struck, but there's also NUNNOVIT suitable for making gunflints. It all has inclusions and such that ruin every piece. I've don't even look anymore. Start with the right stuff, hope you find it local, but also you can buy spalls online.

But it is wonderfully neat to bang and shape rocks into tools/parts same as they did for thousands of years.

m1garand_man · « **Reply #6 on:** March 22, 2018, 03:22:20 AM »

Well, messing around this evening I got one good "flint" out of this chert. Basically I have to work with the Spall as they are and try to break off the parts I don't need. I hope I can figure out which rocks will have the best potential to make good blades where I can break off multiple flints from one blade

D. Taylor Sapergia · « **Reply #7 on:** March 23, 2018, 12:39:46 AM »

To do that requires a lot of skill based on experience. That means making lots of big rocks into gravel. Even a rock that is perfectly square, with ninety degree corners as you describe, can be reduced to have angles less than ninety degrees. You need to get some instruction far more detailed than I am prepared to provide in a paragraph here. Check out you tube...buy a dvd or book, or all three.

m1garand_man · « **Reply #8 on:** March 23, 2018, 04:24:48 PM »

I picked up about a half 5 gal bucket of soft ball size cher rocks from the road side today and messing around for 30 minutes in the garage allowed me to produce one usable "flint" it sparks well. I'll probably use it this weekend to see how long it holds up.

D. Taylor Sapergia · « **Reply #9 on:** March 24, 2018, 02:13:37 AM »

Rich Pierce makes his flints from what he calls river rocks. Being from Missouri, the stone he gets is likely Novaculite or something simliar. I think he gets stones about the size of a soft ball or grapefruit, though I cannot be sure. His flints are awesome sparkers. Maybe he'll divulge some of his trade secrets on reducing stone.

rich pierce · « **Reply #10 on:** March 24, 2018, 03:06:35 AM »

I will do a video sometime. Most of our local chert is “seam” chert coming from layers, so decent pieces usually have flat surfaces. A 1” thick piece the size of a jack o lantern lid can provide a dozen flints sometimes. Rarely do I find a piece of solid chert (no freeze cracks) larger than a grapefruit. I’ve made 2-3 flints from a piece the size of a pack of cards. If I find a spherical chunk I need to give it a hard knock with a big hammerstone to pop a lid off it and give me a striking platform.

One key is using the right size and weight bopper or hammerstone for the piece you’re working. When too light, great speed is needed to effect anything, and results are not good. Too heavy and a small piece you’re working can be destroyed.

Go to YouTube and find Freeze Cracked’s flintknapping videos. He’s not making flints and can take a piece the size of your leg and turn it into one decent spearpoint in 6 hours but his videos show technique well.

This guy is pretty good. Skip to 5:00 in the video. He can work poor rock.

m1garand_man · « **Reply #11 on:** March 24, 2018, 12:27:32 PM »

So out of eveything I have knapped so far I have two good sparkers. Some times I even get a spark or two the linger in the pan for a while which is great.

The big round rocks are hard to get useful spalls off of. They either are too thick or too thin. I'll have to look for flat peices.

My main goal is to produce a good source of "flints" for target practice. If they are reliable enough I may use them for hunting as well.

Robby · « **Reply #12 on:** March 24, 2018, 04:13:31 PM »

http://gvknappers.tripod.com/events.html

They have this every year. Truly amazing what some of these guys can make from stone, using stone tools. They come from all over the country and Canada.
Robby

m1garand_man · « **Reply #13 on:** March 25, 2018, 06:48:22 AM »

Success! I whent and shot today with my home made "flints" and they worked great. This was cooler to me than having good luck with reloading metallic cartridges. To take a rock from the side of the road and turn it into something that can make a rifle fire is a really cool concept.

Standing Bear · « **Reply #14 on:** March 25, 2018, 03:48:35 PM »

Yees it is. I e been lucky enough to get one “serviceable” piece of rock that fit my lock and did indeed ignite the prime s designed. Unfortunately other projects have slowed my developing skills in knapping.

wmrike · « **Reply #15 on:** March 25, 2018, 05:53:29 PM »

There's chert, and there's chert. In a textbook sense it's the same as flint, but typically has included clays and whatnot that render it difficult to work, or even unworkable. It's a gray-scale thing. Part of getting good end results is finding good chert (half the fun) and developing good working skills (the other half of the fun).

Standing Bear · « **Reply #16 on:** March 25, 2018, 07:30:10 PM »

Lots of suitable chert here in the Texas Hill country. More search and research needed.

Daryl · « **Reply #17 on:** March 25, 2018, 10:38:46 PM »

Good video, Rich, Thanks..

m1garand_man · « **Reply #18 on:** March 26, 2018, 04:44:22 PM »

There is a lot of it here in Texas Hill country. The stuff I found was in a road side ditch. The only down side is its 12 miles from work in the opposite direction from home. I hope to find another spot closer to home soon.

Tracker0721 · « **Reply #19 on:** April 19, 2018, 02:53:59 PM »

I’m a knapper and get on the primitive archer forums, those guys are a huge help and quite a few live down in Texas. Maybe hop over there and see if any are close to you. You’ll wanna find Georgetown flint, the stuff acts the exact same as English flint. I was stationed at Ft. Hood and found it from Waco to Austin. One trip with a couple 5 gallon buckets and you’ll be set sir!

m1garand_man · « **Reply #20 on:** April 19, 2018, 08:35:58 PM »

Is the Georgetown stuff blackish in color? I have found some like that locally but havent worked with it yet. What I have been finding is more tan. It's super tough and super tough to knap but it also makes some very long lasting if somewhat oddly shaped flints. I am also stationed at hood by the way so the stuff is everywhere as you mentioned.

Tracker0721 · « **Reply #21 on:** April 20, 2018, 06:35:38 AM »

You’re in the hot spot for good flint then! I got out a couple years ago but I’ll see who I still know that way that can lead you right. Over in Belton or Temple is a guy named Curtis Smith who is the best knapper I’ve ever known and he buys flint off the road crews and makes gun flints perfect and FAST! He’s on Paleo planet forums still I believe. I’ll shoot ya a PM sir

Oh, and Georgetown is a blue gray and has a white chalk like outer layer. There’s cow patties that look like the color of mud maybe sorta black and look the shape of patties. North fort hood has Owl Creek Yellow which is great chert. And there’s plenty of other stuff that I don’t know the name of. Collecting on Hood is frowned upon but the surrounding areas are loaded too. I should have a “treasure map” somewhere. In the 80s they did a geological and archeological survey identifying prehistoric quarries and all the knappable rock areas and I had the maps of it.

m1garand_man · « **Reply #22 on:** April 21, 2018, 07:09:52 AM »

I indeed have some Georgetown flint then. I found it about two weeks ago walking around. I thought it was actual flint rather than chert but that didn't make any sense since I understand true flint only comes from a few places on earth.

I did know as soon as I got to hill country and saw so much chalk that there would be good rocks for knapping.

IIRC Texas was once under water as part of the great inland sea in prehistoric times. This would have made optimal conditions for the formation of silicate rocks like chert.

All this makes me hopeful that back home in central Montana there will be similar rocks. We don't see much chalk but centrap montana was part of the same sea floor once.

thecapgunkid · « **Reply #23 on:** April 24, 2018, 12:05:56 PM »

Dunno about the excellent work in the photo's, but when you wear a Gneiss Chert make sure your tie matches.

Hungry Horse · « **Reply #24 on:** April 24, 2018, 07:34:49 PM »

In the back of one of the paper back books on trade guns there is a step by step process for making gun spalls, and true gun flints. It shows the special tools used to make gun flints. It’s a lot different than native blade knapping.

Hungry Horse

News:

Author Topic: Having issues knapping chert (Read 5466 times)

m1garand_man

m1garand_man

m1garand_man

m1garand_man

m1garand_man

m1garand_man

m1garand_man

Tracker0721

m1garand_man

Tracker0721

m1garand_man