How to break up flint?

[SimonM]

I have been given a couple of large lumps (nodes / nodules??) of flint for firelighting.

They all have a dirty white, hard coating and are a pig to break up - I've been using a cold chisel and lump hammer.

So, over to you lot;

Is there an easy way to break up chunks of flint into fire kit sized pieces?

Simon

 

[bushcraftbob]

I've been using exactly the same method lol!

 

[Shewie]

Stick it in a pillow case and throw it out of the bedroom window.

No idea really

Have you tried putting it on a hard surface and giving it a good whack with a rock ?

Goggles and gloves though mate for gods sake

 

[SimonM]

Stick it in a pillow case and throw it out of the bedroom window.

No idea really

Have you tried putting it on a hard surface and giving it a good whack with a rock ?

Goggles and gloves though mate for gods sake

Nice idea, but we live in a bungalow

Defo on the goggles - first time I hit it there were little shards flying everywhere.

Hard stuff though, my lump hammer just bounced off it.

Simon

 

[British Red]

Dear Gods its easy.

You need to develop a core.

Do this by orienting the nodule to get the worst of the odd edges off.

Everywhere there is a nice corner, develop a platform (flat bit at the top of the corner). Strike the platform back from the apex of the corner with a hard, sharp, strike with a hard rounded instrument. Traditionally a hard round "hammer stone" - but the round end of a ball peen hammer works.

You are looking to develop something like this

You flip it round and round in your hand developing platforms and striking blades from the core with the hammer stone

Hope that helps a bit

Red

 

[spamel]

I'm sure if John Lord (age unknown, but no spring chicken!) can break a nodule the size of a medicine ball with a hammer stone, then you'll find a way too! Coretex is a very good shock absorber, it doesn't respond the same way as flint so you really need to whack it to get the first piece off. Me, I just give the lump to John and let him crack on!

 

[MrPhil]

Cool, I might get some and have a play. Its a shame flint weighs so much as I live near the beaches where this stone grows on trees and so would cost a fortune to ship anywhere.

 

[British Red]

I'm sure if John Lord (age unknown, but no spring chicken!) can break a nodule the size of a medicine ball with a hammer stone, then you'll find a way too! Coretex is a very good shock absorber, it doesn't respond the same way as flint so you really need to whack it to get the first piece off. Me, I just give the lump to John and let him crack on!

In best "four yorkshiremen voice"

Medicine Ball? You had it easy!

We had a day with John a couple of year ago - I remember being gobsmacked when he hauled out this one

The man is bloody amazing to spend a day with - and stupidly cheap for one on one tuition (or spilt with a mate for a madly cheap day). A world expert instructs you for about a tenner an hour. Unreal!

Red

 

[SimonM]

Thanks guys, I knew there was an easier way than mine!

I'll have a play over the weekend.

Simon

 

[troy ap De skog]

if your useing it to make blades... leave it ina fire all day and cool naturaly then wack it with a hammer stone.. and it will break up into razor sharp slivers..
that you can work from....

 

[Greg]

A mate of mine brought me a couple of big bags of flint the other week from Salisbury Plain where he lives. Lastnight I was attempting to get some shards off a decent size nodule with a hammer stone and the flint broke the hammer stone so I resorted to using my escavation hammer/pick!

 

[SimonM]

Had a quick go in the garden last night, using a rounded piece of flint as a hammer.

Damn, that it so much easier to do

I oly stopped because mini-me complained that I was keeping him awake!

Roll on Saturday, then I can have a proper play!

Thanks again guys!


Simon

 

[spamel]

Just be careful with the debitage, it can be razor sharp. John Lord suggests knapping in an area where you can clear up the broken off pieces and bung them in a rockery or similar so that in a few thousand years time it isn't mistaken by a young archaeologist for ancient stone working by stone age man. Also, don't knap indoors as the microscopic dust given off as a result of knapping can be breathed in and will over time give you silicosis, your lungs will be irreparably damaged and you will die!

BR, how did you get an in focus shot of John? All of my pictures came out with him totally out of focus even though people next to him are perfectly in focus! For some reason, my camera doesn't work on John Lord!

 

[Le Loup]

Simon, I protect my eyes and simply hit it with a hammer or another rock. A trip down to the coast will net you a boot load of flint off the beach.
Flint is found in chalk, hence the white stuff.
Do be careful, flint when broken is sharper than a surgeon's scalpal, and flying pieces will cut you if they hit. I found the safest method is to wrap the flint in an old sack or wrap it in cloth, then hit it with a hammer on solid ground.
Le loup.

 

[stretch3144]

Wrap it in a piece of cloth then whack it with a ball pein hammer!
First attemp was without the cloth and the flint went everywhere! All over the garden so the second lump was put in an old yellow duster then given a good whack.
Broke into lots of small pieces and a manageable lump to use with my steel.

 

[robin wood]

There is lots to learn about how and why flint breaks up the way it does and I know very little but my first big breakthrough came when I realised that if you send a shockwave into the flint, eg whack it with a hammer, where any other stone will break in line with the direction of the force with flint you get a cone of shock which causes fracture at 45 degrees to the line of force. So is you have a nice flat face and you want to take a flake off you don't hit nearly parallel to that face as I would expect you hit down at 45 degrees, I would expect this just to chip a bit off the corner but no it takes a big flake right across the surface.

 

[Matt.S]

Flintknapping by Whitaker is probably the best primer, with heavy emphasis on getting one's hands dirty and bloody. Lots of information in there regarding platforms, angles, shockwaves etc. Even crude flaking of a flint nodule is infinitely better than 'hit it with a heavy hammer til it breaks'; it's more controlled, you get more useful results, less mess, less shrapnel, less wastage and less energy needed.

Bruce Bradley suggests knapping on top of a tarp if the surface can't be swept.

 

[Stryker]

I found some good size pieces on a local beach yesterday, and repeated throws at a large rock with the best bit just made it bounce off. Cue my ten year old son who threw it at a rock, while we both stood wellback, and it split in two with his first throw. We came back with 5 good pieces for me to use.

Beginners luck, or just lucky young sod?

Was grateful anyway, worked a treat tonight with a great shower of sparks onto the char cloth.