What’s in the Saggar?

For the uninitiated, I should explain what a Saggar is, it is a big piece of pottery that smaller pottery is sealed in.  Traditionally this was done in Stoke on Trent to protect the pottery from the coal fire that they fired their kilns with. Modern Potters use them to get a reduction environment inside an electric kiln, this stops the kiln from getting damaged and brings some different effects to the pots.

she sells seashells by the sea shore

Seashells lining the bottom of the Saggar, the only picture I took before the firing.

I threw a a saggar a few years ago and it has been sat on the top shelf on my studio for a few years now, not really having the confidence to use it, as I was afraid I would damage my kiln regardless of it being sealed. I also didn’t take many photos because I wanted to do it in secret as I was convinced it would go wrong and in some ways it did.

The kiln was fired to 1200C (2192F) which was cone 7 flat due to the fact my kiln doesn’t fire very fast so cone7 always drops and I don’t have a cone 8 to check it.  In the Saggar I had a mixture of seaweed, blackcurrant branches and  lump charcoal rather than briquettes.  Everything is separated by seashells so the don’t stick to each other.

dark and gloomy

The results of the firing the cup at the top has been lifted out to look at it and then put it back in on its side by mistake

When I first opened it my heart sunk, it was dark gloomy and my saggar split down the middle. It was it was only once I lifted them into daylight, that I could see how amazing the results were, and there was no real damage to my kiln or kiln shelf.

This pot like all wonky pots is a mixture of stoneware and earthenware clays with added homemade grog, splashed with porcelain slip.

splish splash spolsh

Wonky pots as they have had their slip added

And now for all the results:

Wow, just wow

Finished Wonky pot the surface is very mossy and isn’t much trace of the glaze or the porcelain, it has fluxed with clay body and the cobalt brushwork has etched into the clay.  To me it feels mossy to the touch

Flashing

You can clearly see where flashing on the base where the seashells have protected the base of this cup

thats some big brushwork

I love the slight reduction speckle in the clay body, cobalt becomes much stronger, and starts to spread through the glaze, so if I did it again, I would reduce the strength of the cobalt, use the carbonate rather than the oxide.

Teeheehee its naked

The flashing on these is amazing and the shapes of the seashells are so clear

:O naked tile

Top side of the tile where all the seaweed and ash has settled. This was unglazed so any glaze was formed by the materials in the saggar. The marks left by the seashells really help tie the whole thing together.

So in conclusion…

I really want to fire in a saggar again but my saggar is an ex saggar, so I will have to make some new ones and seal them with wadding material rather than just my normal clay as I don’t have alumina in stock.

I will probably make them with a slab roller as there is one at my day job. And then fire everything separately so I can understand what each one is doing, there are also other materials I want to test in the saggar.

About Joseph Travis

Maker of ceramic objects, Ceramic Researcher and full time dad to two boys
This entry was posted in Eperiemental firing, Film, Learning, Research, Saggar, Slip and tagged , , , , , , , , , , , , , , . Bookmark the permalink.

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