Open fired pottery.

Hiya, I'm currently making some replicas of Neolithic pots, I'll post some pictures soon. In Africa the potters use similar methods to make and fire thier pots out in the open and I found this documentry which is really quite interesting: https://www.youtube.com/watch?v=52HKSwkI1hs

will you be putting a simple patern on them? - the other question is will you be making the fire by hand - lol.  

That's fascinating stuff. I have been wanting to do some Raku pottery for a while now and it's interesting to see a similar technique being used on the African cooking pots. I wonder how hot the fires get and what kind of time the firing takes.

Lots of pictures if you please  

Yep, the fire WILL be made by the fire drill/flint strike-a-light and marcasite combo, I will not be defeated!
The fire only needs reach 550-600 degrees for ceramic change to happen." />The firing should only last an hour or two, time enough for the rather thin sticks to burn through, you don't need a lot of fuel to fire the pots, most folk who try to fire build a massive bonfire!
I nabbed this pic from somewhere else and you can see a rather chunky log about to crush the pot on the right, best avoided.

I wonder if I could fire pots in my forge  

SteveW wrote:I wonder if I could fire pots in my forge  

a forge, now that sounds interesting.

All you need is a little bit of fire, easy on the bellows...

" />Ok, if you want to make some pots that you can fire in a bonfire or a chiminea you should buy a bag of Crank clay. This is a very forgiving mix of clay with a good amount of sandy grit added, still you need to add more large grit, here i'm abusing some "pot boilers" or fire cracked flint, record them first with your local F.L.O. (I'm sure they will love you for it!) then get pounding with some rocks, I've found two medium sized ones will make a good sized pot. If using fresh flint make sure you burn it first, instead of flint you could add crushed shell grit to the mix instead, again put it through a fire first, all grit must be inert when fired proper.
If you want your first pot to fire ok and not pop when fired you could go a little further (like the Anglo Saxons did with thier pots) and add some herbivore dung like horse poop, cow, deer or even rabbit, this additive will burn out and make sure all the water remaining in your (dried out) pots will have an escape route, although the pot once fired will not be water tight.
It is steam trapped during the quick temperature change that will cause a pot to fail, so beware of making extra thick walls where moisture can get trapped.

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With the fire cracked flint crushed, add it to the Crank clay, you can see that it is quite coarse still. Squish untill you have an even consistency, the mathematical way would be to (from this point in the picture) to roll it into a rough sausage, flatten then fold in half and repeat, each fold and flatten will double the mix like bacteria breeding and within twenty folds the mass would have thousands of individual fine folds ensuring an even mix. This tip came from a potter of several practicing decades and can be applied to anything that needs mixing of this consistency.

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In the African pottery documentery the first woman used an existing pot as a mould for the base of the pot she was building, so I thought this needs to be tried.
I rolled out some clay and it stuck to the board, so I remade the ball and rolled it out again, this time with something to stop it from sticking. Looking in the cupboard for flour, I picked up icing sugar and thought aha! That will do. Kind of a bad choice as it made the surface of the clay more sticky to the touch but at least it didn't stick to the board this time. The sugar will burn off when fired.
Here i've trimmed round the bottom edge to make it even with the flat spatula on the right and I just left it in the sun for over an hour to firm up before removing the base from the mould.

Forgot to say that a large plastic bowl would work just as well as a mould!

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Once the base has firmed up it is safe to handle without it collapsing on you. I put the base in the mortar to stop the bottom from being flattened on the board, this can be turned round as you work. Start to add the rolled coils of clay smoothing them in with the layer below one at a time, all the while trying to keep it all as even as poss.
I'm going for an undecorated Early Neolithic Grimston lyles ware bowl, just the rim to add now.

This is really fascinating stuff, I'm going to have to have a go at this when I get some clay sorted out.

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Thanks, Do get Crank clay as it will fire better than other clay mixes. You could go the whole hog and pull raw clay out of the ground and add loads of pre-fired grit, now that is a bit of a mission!
This is where I stopped squidging clay around. The rim is on and slightly lumpen, but hey, so where the originals. When it was leather hard I used the back of an old soup spoon to smooth out the surface and do some final fine shaping on some of the bigger lumpy and irregular parts of the pot. This part is very relaxing and satisfying!
Time to dry it out, but not too quickly as this could form cracks.

" />Here you can see some of the smoothing marks left by the spoon.

now thats smart, thanks for showing the stages, i think your next step will have to be to collect your own clay, -

why do you add fired ground flint?

" />This is an actual Peterborough ware bowl with lots of chunky flint mixed in, the flint is added as an opener, to "dilute" the clay with inert chunks. This allows the water/steam to escape around the temper as it's rightly called. It helps the clay survive when firing in a bonfire rather than a kiln.

i wonder if the recess is designed so it could be supported with a rope aroundto form a handle? - thanks for the info on the flint - i never knew that.

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I have read about the recess possibly being for suspention, once this one is fired I'll see if it works without burning through the cords. The tools for the impressions on this Peterborough ware type bowl are a piece of nettle string on an offcut of Hazel and a small bone, no idea what the critter was though.

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This Beaker is one I made years ago and never got round to firing, thankfully it's still in one piece.
this one was pure "Crank" clay with no added inclusions, the plan was to have it high temp fired in a kiln. I may get away with firing it in a bonfire as the walls are really thin compared to the other pots I've made recently.

i wonder if the patern they put on was for a reason as well as decoration - maybe grip when carying or somthing to do with the firing.

I've read that the decoration may be an attempt at making it look more like a basket or something woven, I'll bet it's functional as well though, less chance of dropping a bowl if its roughly textured on the outside... and it looks good!

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Right then, I'll be back to some flinty suff soon but first the pottery firing...
Small fire, non pre-warmed dry pots and an uneven start to the fire, I cannot envisage anything going wrong at all!

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Pop goes the beaker! The surface had fire spalled by this point.

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And then the big bowl joined in. Pop.