Sunday 28 June 2015

A tip for glazing pots without a footring


Many of the pots I make these days don't have a footring, and if the pot is a rounded form, then finding a way to dip-glaze them without leaving finger marks can be challenging. As an alternative to dipping tongs, one possible solution is to use old pieces of kiln shelf to create a foot for the pot.

First I take a piece of kiln shelf which already has batt wash fired on to it. Using a hammer or a small rock, the shelf is then broken into smaller and smaller pieces, until I have one of suitable size and shape to fit onto the base of the pot to be glazed. Next, the base and the chunk of kiln shelf (a side with a robust layer of batt wash) are coated with PVA, glued together, and left to set. If the batt wash is flakey or powdery, the pot can easily work loose and drop off.



I find that on a bisqued pot (fired to around 1050 C ), the clay absorbs moisture from the glue so it dries very quickly, often in a matter of  minutes. Once the "foot" is firmly fixed the pot can easily be dipped very close to the bottom edge.


So far I have tended to use this method with small to medium sized pots, but there is no reason why it couldn't work on larger pieces (perhaps using several glued supports). However, handling and moving them onto the drying shelf could no doubt become more problematic.



It's important to make sure the pot is stable when stood on the fragment of kiln shelf, as it may move slightly in the kiln as the glue burns away during the glost firing. Also precautions should be taken regarding the fumes which will be given off by the burning glue, so safe ventilation of the kiln is essential.The same technique can be used with shelf supports or pieces of wadding from previous firings, but again, one needs to be careful that the pot will remain upright when fired.


Another advantage of this method; no need to add wadding when loading the kiln, and it doesn't annoyingly drop off down the side of the shelf when you start rearranging the ware!

And now a shameless commercial plug;  I've added a link to my online shop, Birchcroft Ceramics, in the sidebar of the blog, and just this morning listed a wood-fired tea caddy or food storage jar:


Tea caddy, height approx 4.75 inches

I hope you might like to to have a browse through the pots some time, and please don't hesitate to e-mail me at mark_smalley@yahoo.co.uk if you have any comments/questions or wish to enquire about other pieces which are shown here or elsewhere on the internet.
 
Thanks for reading.



Sunday 14 June 2015

Here comes the sun .. soon hopefully!

Summer hasn't quite arrived here and the very poor weather recently has made it impossible to fire my gas/wood kiln outdoors. The BBC is even predicting a frost in parts of England tonight which is pretty unbelievable for this time of year. In the mean time I have fired the electric kiln again, mainly to test some new glaze and slip combinations and a glaze recipe I found in the book Dry Glazes by Jeremy Jernegan. This is a matt copper glaze ( Taffy Matt by V.Cushing ) with a small addition of tin oxide, which is recommended to be fired to cone 10 in a reduction atmosphere. Quite intriguing as the photo of the test tile shows the glaze to be a dark reddish brown where thicker and light green where thin, whereas I would have expected it to be shades of pink where thinner. I will try it in the gas/wood kiln soon, but in oxidation (fired to cone 9) it has come out like this:

Sake cup

Small vase, approx. 2 ins diameter


Quite an attractive glaze, with some subtle variegation even within the grey areas. It highlights the carved areas of a pot in exactly the way I had hoped.

A couple of pieces were fired with the combination of Oribe and dolomite glazes I have used before. It came out really well on this heavily textured vase where the second layer of glaze was poured rather than dipped. Next time I intend to leave more of the green glaze showing as the contrast has worked rather nicely on the underside:

Vase, approx 6 inches tall

Vase, underside
Bowl, height approx. 3 ins

Interesting that on the above bowl the top layer of dolomite was dipped over the rim, but has dropped down over half an inch in the firing. It hasn't done that on the other vase, presumably because the top of the pot is more horizontal..

Another pot glazed with Oribe was this tea bowl, this time layered over a dark iron oxide slip:

Tea bowl, height 3 ins, diameter 4.5 ins

And finally something a little different .. a textured pot, which was initially thrown as a closed form, then laid on its side. The matt copper ash glaze was brushed on, hence the variation in thickness and hue:

Ikebana vase, height approx 4 inches

I feel this vase form could work well for flower arranging.

Thanks for reading!