Crack pots first attempt

[Bretts]

Thanks for your thoughts Kunzea.
I will be sure to take your suggestions when I decide on a finish. I think you may be onto something with the oxides with these two. Most of the different glazes I have used have this colour change I think you are suggesting. Like this one I posted elsewhere.

pot.jpg

I usually use one of those green scourers to fine tune a pot before bisque firing, I will be sure to reduce that concave when I do.

[Bretts]

Promised an update today Sorry not much to add. After rolling the sidewall clay out on a fibro sheet and leaving for a couple of hours it did not act as well as I was hopping.
It seemed to be drying all through more than I was hoping . I tried wetting the inner surface but that seemed to miosten all the way through and reduced the cracking abbility. I still got through a few pots today though, sorry no pics yet.
I am looking forward to getting some sodium silicate to see if I can get a better consistancy to the drying of the outside.

[Pat K]

Not quite sure what you hoped to achieve Brett. Were you trying to dry the outer side of the slab or the side on the fibro? Remember, the fibro is porous and will be drawing moisture out of the clay, so that side will be drying. Living out west, in low humidity, the upper face of the clay slab will also be losing moisture unless you protect it from the air. If it was me, I would be putting the slab on a plastic sheet and letting the air (NO SUN) dry one side until it reaches the right moisture content.

Pat

[Bretts]

Not quite sure what you hoped to achieve Brett. Were you trying to dry the outer side of the slab or the side on the fibro?

The side on the fibro.
I did try one with the top surface protected and it didn't work for me. Maybe that was because of talc I also spread on the fibro(it seemed to soak into the clay and then protect it from the fibro) and that I only put the clay on the fibro after rolling out. I may have to try again without the talc but with the plastic cover.
I will also try your air dry suggestion Thanks

[aaron_tas]

very nice attempts soltan

i hope to be joining a pottery class soon...

[Lynette]

hi Brett,
Just found this thread. It looks like you are going well, if you don't get some sodium silicate by the school seminar let me know and I will bring you some. Try the ball clay method and see how that works on the wheel. I know it works well on slabs and strips. I have another method that was shown to me by a Swiss potter called Steffan Jokob. Have a look at his web site. He makes huge cracked plattters and raku fires them. I will show you this method when I see you. It is a bit hard to explain with out seeing the details.
Lynette

StefanJakob_1_2008.jpg

[Bretts]

Thanks Lynette I could not find much about Steffan Jokob. I hope I make It to Bonsai by the Harbour again this year?

[Bretts]

The first Pots have made it through bisque firing with no worries. I took advice and used an oxide wash on these two. I also added a glaze around the rim that should drip down the pot. I think glaze firing is in a week or two so I hope to have more to show then. There are a few other pots in with them but my better pots are still waiting bisque firing.

I have been spending a lot of my potting time learning to make oval pots on the wheel thanks to pjkatich. I have made a few more crack pots with various slab and pinching techniques in the mean time but today I tried making crack pots using the wheel.

After giving up on using paper clay on the wheel as it kept moving off centre with the pressure I needed to manipulate the tough clay. I moved onto 5a dark. It felt like butter under my hands after the paper clay.
After making a rim a bit smaller and thicker than finished I painted it with sodium silicate. As I think I am putting to much of this on I have dried with a small flame gun or hair dryer.
Using only inside pressure the shape is pushed out.
I think I could have gone further with the first one but I was hesitant to stuff it up. I am not happy with the profile on this one but I will take it as a first attempt.

c1.jpg

I would have used a slip if I had had one handy

The second one is made from a clay that I collected from a friends farm. Will have to wait and see how it fires.

With one in the bag I thought I would be a little more adventurous with the second one. I had my doubts but I think I pulled of an interesting pot.

cr1.jpg

cr2.jpg

cr3.jpg

cr4.jpg

[Shane]

Awesome pot, Brett: I really like your second one. The smooth rim is a nice contrast and will make it much easier to trim the base later on.

On Wednesday I also tried for the first time to make cracked pots, but used ball clay. I've put the ball clay over the rim also and have big jagged cracks along the rim. Not sure how I'll trim that successfully. Definitely will need to use a foam bat, but will probably have to let it over dry, then re-wet the base to trim. No photos unfortunately; the studio is too dusty to trust my good camera there.

[kitoi]

Nice job Brett!! 2nd one turned out great, looking forward to seeing the finished product.

Stiff clay can be a bear to throw with but you can get some interesting cracks that you can't with softer clay.

[anttal63]

great job brett!!! ya doin real good mate. look forward to seeing the finish.

[Bretts]

Thanks for the pats on the back

Stiff clay can be a bear to throw with but you can get some interesting cracks that you can't with softer clay

Until I can find where to plug in the kick wheel I think I might stick with the soft clay for now

[kitoi]

You just need to develop your leg strength

I threw a 7kg lump on my kickwheel the other day, don't know what was more tired my legs or my back.

[Bretts]

LOL I will get the scales out

[pjkatich]

Brett,

Looks to me like you have a good handle on this process.

From the photos, it appears that the second pot is going to be an oval. If so, I look forward to seeing the final results.

The second one is made from a clay that I collected from a friends farm. Will have to wait and see how it fires.

Do you know the firing characteristics of this clay? In particular, what is it's firing range. If you are not sure, I would run a small test piece through the entire process before committing a good pot. If you over fire the clay, you could wind up with a big mess on your hands. Likewise, if you under-fire the clay, the pot will not vitrify properly and will be prone to breakage.

Cheers,
Paul