Throwing - it's like riding a bike (or is it?)

Some days I just struggle with throwing. I don't know why - if I have to be in the right frame of mind, concentration at the right level, pure luck, practice, right weather conditions or some other black magic.

It's apparently not like riding a bike - although I do cycle every day but don't throw every day. If I cycled like I throw some days I'd be broken and bruised.

Anyway here are the pitiful offerings I have to show for a throwing session at the weekend. Porcelain again, which I'd been OK at previously.

Some shoddy attempt at throwing porcelain - ha!

If I'm honest I don't think I prepared the clay well enough - possibly it had started to dry out a bit or affected by sub-zero temperatures as it felt uneven as I was throwing it, and lumps seemed to appear in the walls of the bowls.

Well its all practice, and reclaimable clay. Gotta take the rough with the smooth.

Coral-inspired bowl - all out in one piece (almost)

I held my breath as I opened the kiln half-expecting to see a pile of ceramics sticks on each kiln shelf, but amazingly, each one of these three pieces has survived.

The most delicate was the small random piece, one 'tentacle' broke off immediately on my picking it up out of the kiln - this is probably because none of the tentacles are connected and each one individually is very fragile. This was confirmed by checking the broken piece to find out that the inside of the tentacle was actually hollow - so the slip hadn't really permeated into the string when it was cast.

Coral-inspired tentacle piece - bisque fired

Coral-inspired tentacle piece - bisque fired

The shallow bowl also survives and felt pretty sturdy (but light) when lifted so there's probably an element of hollowness to it as well.

Coral-inspired flat dish bisque-fired

And the large bowl also came out in one piece. Result!

Coral-inspired medium bowl bisque-fired

Next step is to glaze them gently for the final firing. Here's a closer view of the texture on the outside of the pieces.

Coral-inspired medium bowl bisque-fired (side view)

Further experiments with coral-inspired bowls

I've just loaded the kiln with these bowls - some more attempts in a variety of sizes and shapes based on the method originally devised to create the bowls. Also some test tiles went in so that I can try out mixing up a wider range of volcanic glazes using silicon carbide.

Top-loading kiln with coral bowl and earthenware test tiles

Even though the end result is beautiful, the pieces are fragile and often break during the making process so I have been experimenting with different methods to strengthen the pieces enough to be able to handle them (gently) without them breaking.

Today three pieces went in - one large bowl, a large disk and a smaller 'random piece. These were cast over some new plaster moulds I made by filling various found plastic containers.

The kiln programme for the bisque firing was:

1. Up to 600ºC at 150ºC per hour
2. Full power up to 1120ºC
3. No soak
4. Cool down

Here are the three greenware pieces:

Small coral inspired random piece - greenware

Large coral inspired flat bowl - greenware

Large coral inspired rounded bowl - greenware

With last bowl I made I experimented with glazing and firing the greenware in one go - including adding a double layer of glaze for strength. This time I have layered the 'fingers' of the bowl more densely and allowed more slip (petra smooth) to soak into the string without squeezing so much out again.

The results will be evident when these come out of the kiln later. Previous attempts have shown that some of the pieces were so fragile they didn't even survive the bisque firing.

The firing also contained a number of petra smooth test tiles.