Temper for clay

[Toddy]

I've got bucket of good Lanarkshire blue clay ( I asked the workmen who were digging up the roads around the corner if I could have some and they obligingly filled the bucket *and* carried it to my car for me )
I want to make some pots like the Beacharra Ware ones; think hearth fired Neolithic and you won't be far wrong.
Thing is, those pots were made using shell temper. Anyone know if I can use sand instead? Or does the shell actually 'burn' in the firing? There's no way I'll get my fire hot enough to melt sand into glass.

cheers,
Toddy

 

[weaver]

We made a primitive hand dug kiln fired with wood burning all night and most of the next day when I was in college. There is a name for the sand and clay mix but I don't remember.

Anyway, we dug a hole large enough to hold all the pottery, placed the pottery and dry wood in the hole, built an earthern chimney at the top end and a open hole at the lower end to feed the fire. We kept feeding wood to the fire then slowly fed less wood until it was safe to let the clay cool.

The flue like construction made the fire hot enough to fire the clay and melt the surface sand mixed with available ash from the fire into a nice brown glaze.

 

[Eric_Methven]

Get a bag of sea shells from a novelty shop and ground them up in your pestle. Is the clay relatively free from other contaminants? If not you may need to filter it or you'll get failures when you fire the pots.

Eric

 

[Toddy]

It's beautiful stuff; the foreman called it Puddle Clay and the local quarries used to produce the clay for the fancy tiles that lined the closes in Glasgow's tenements.
Okay then, shell it is. Any idea how fine I need to grind it?

cheers,
Mary

 

[Tadpole]

It's beautiful stuff; the foreman called it Puddle Clay and the local quarries used to produce the clay for the fancy tiles that lined the closes in Glasgow's tenements.
Okay then, shell it is. Any idea how fine I need to grind it?

cheers,
Mary

Quick search of the net and it seems that prehistoric Neolithic pottery seems to have two sizes less than .02mm (fine) and bigger than .02mm (course)
the process seems simple enough Ok this is from mexico, but I'm sure the process would work for Scotland

 

[Toddy]

Oh nice link Thank you.
I've got a new stone to be made into a saddle quern, I might just manage two jobs at once if I use that to grind the shells down.

Cheers,
Mary

 

[drat]

white hardwood ash can be used for your temper.burn hardwood and use only the white ash that is left and not the charcoal.