Tuesday, 8 March 2011

Glaze/Slip Test Results.

Unpacked the kiln this morning, from a very quick glaze firing yesterday, back to the old temperatures though (1080 on clock at 150 an hour, with 20 min soak, usually yielding cone 02 half down.)

So far, so good.  Usually, a set of beakers like this would be mostly showing the peeling (or the snail trail sign of it) and all would be gone after a day or so.  So far, no signs on any of them.  Not unexpected - these are all much lower silica slips and fit much better.

First up, the 50/50 hyplas/grolleg mix isn't as harsh as I'd thought it was going to be, but it is pretty white.  I like the middle one of these, which was lower down in the kiln and obviously got hotter.  The slip has melted in to the glaze a bit better, which is nice. 

Next, the AT ball clay slip, which, again, is nice.  This was the easiest to use and has shown consistency through out the firing.  Not sure i like that it's consistent though.  The clear glaze (the one with all the china clay in it) has gone cloudy again.

The last one is the strange mix of 1 part china clay, 2 parts hyplas and some red clay.  This went pink in bisque, and so I'm surprised at what came out.  The clear glaze is nice and the others I thought would melt in to the glaze but it hasn't.  Well it has on one, but I still like it.

In fact, i've just remembered, on one of each test, I watered the slip down a bit, and on each slip test there's one that has sort-of disappeared a bit.  That's ok.

Anyway, I have to decide which one to use.  I have already used the AT slip as I desperately needed to slip some pots, so I mixed a little up, in anticipation of preferring that one.  But actually, it's the one I like the least, probably.  The first is a bit harsh but the last was awful to decorate through.

I was lucky enough to visit chez Cullum at the weekend (thankyou) and saw the awesome collection of pots (in the awesome house.)  They have quite a few old Winchecombe cups by Sid Tustin and it was nice to see those.  Mine are no where near as nice - they're too big for a start, massive in comparison - but that last slip I think comes closest.

Right - well it's a beautiful day here again, but we had one hell of a frost last night.  I dare not check the pots in the shed for I think I know what I'm going to find...

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