Throwing large

I've been throwing larger pots recently and have had to put in some concentration as well as sweat. As I don't throw larger pots very often, I have to re-learn how to do it. This got me thinking that I should write down the little lessons that I learn and save myself some time in the future. Hence this post. These are based on my experience of throwing 10lb and upwards lumps of clay.

1. Make sure the clay is well kneaded and not too hard. This really helps when it comes to getting it centred. Well kneaded clay responds much better when on the wheel.

2. Centering - this is something that really takes a bit of muscle (see point 1 - clay that's not too hard). I try not to rush centering larger lumps of clay, you have to be patient. Keep the pressure on the clay using equal pressure with both hands - left hand from the side right hand from the top. Use the full spread of your hands. With larger lumps of clay I use my forearm as well! Be beligerent! You're the one in charge and the clay will eventually respond. The main thing is don't rush.

3. Opening - again you can't rush. Concentrate on forming the base of the pot. I tend to pull the clay out wider than I want the eventual base as when I begin to pull the walls up the base naturally gets narrower.

4. Pulling the walls - As with all pots, get the height first (don't rush). I've tried several ways of getting the walls to come up consistently from bottom to top. There are several techniques that you can use -fingers,  knuckle lift, palm lift etc. I've tried all of these, but tend to encounter problems with the clay getting 'dry' during the pull causing an uneven pull. Personally with large pots I prefer to use a sponge in the right hand to ensure that the walls remain lubricated during the lift. As you make more pulls take care that the walls at the top don't get too thin - remember, you've still got to leave some clay to create the width! make sure that you're bringing clay up from the bottom, but be careful that you're not digging in too much at the bottom with your right hand. If the walls at the bottom become too thin they won't hold the weight of all of the clay above. Conversly, if the walls at the top become too thin then they'll fold. Leave plenty of clay at the top to make your gallery (if you're including one).

5. Add the gallery before shaping the pot. If you try to do this when you've made the finished shape then chances are the downward force that you'll need to apply when forming the gallery will cause the walls to buckle.

6. Form the shape of the pot carefully and always keep in mind that the clay at the bottom of your pot is carrying a lot of weight - pull it too thin and it'll slump. If it does start to lose its shape and you try to get it back into shape you'll more than likely cause the top to lose shape and at worse slump.

7. Know when to finish. Something i never seem to learn!

I'm sure that there are far better guides to making large pots, these are what seem to work for me.
I'll try to make a video and put it onto my youtube channel next weekend.

Big pots.

I've been quite busy recently, getting pots made. I made a few tea / coffee cadies and posted some pics on my facebook page. This led to someone asking if I could make a bread crock for them. I don't tend to throw large pots very often as they take up so much space in the kiln. However, as I have a couple of tall pots sitting on shelves in the studio waiting to be fired I thought that one more large pot could make a kiln full of these bigger pots. The bread crock was made from around 9lbs of quite stiff clay. It was a real wrestling match getting this centred and I probably could have saved myself a workout by using softer clay; lesson for next time!
I've just finished lugging the bread crock and I'm pondering what if any decoration it'll have when fired. I also threw a handful of soup bowls tonight with a flat rim that'll be great for adding decoration to.
I'm really enjoying making pottery now that I've fitted a stove in the studio. it's so much easier to find the motivation to go into the studio when it's warm in there!

I included the mug in the picture to give some indication of the size. The picture on the left was pre lugging. Sorry about the poor quality of the second picture.

 

stampers

I made some stampers for the coffee and tea caddies. I'd have like some different lettering, as these weren't easy to remove from the clay after pressing in. I did dab talc over the clay, which helped a little. hopefully i'll have some pots to use these on soon.

Great article on reduction firing

I've jsut found a really good article about reduction firing a gas kiln, written by Linda Arbuckle. See it here: http://lindaarbuckle.com/handouts/reduction_fire.pdf
I've clearly still got lots to learn, but thanks to articles like this hopefully each firing should see better results. Looking forward to the next kiln load now!

The firing results

Overall I'm really pleased with this firing. I left the reduction until cone 10 was reached and then soaked at this temp for an hour. The blistering seems to be less prevalent. A couple of the storage jars are cracked, but I think they were already present before firing, due to the clay freezing while wet.

Hot, hot, hot!!!

Almost there! Actually, I took this about an hour ago, and the kiln soon reached cone 10 after this. It's now in reduction.
I lit the kiln at 9:30 am and it's now 8pm. In the past I've put the kiln into reduction before reaching cone 10 and then turned it off almost as soon as it got there. I'm going to let it soak for an hour tonight though and then gradually reduce the gas pressure for a while afterwards. The reason being the glaze in the last firing was riddled with pin holes. Hopefully leaving it for longer will give the glaze time to heal itself. I've read that the pinholes are caused by gases escaping from the clay body. The clay that I'm using at the moment has more of a rough / porous looking surface when bisque fired and is possibly why the problem seemed more evident in the last firing. In previous firings with the finer white stoneware the pinholes haven't been much of a problem.
I'm also going to allow the kiln to cool for longer and won't open it until Tuesday night.
I'll try to post pictures then.

paintings and pots

Hello, sorry it's been such a long time since I posted! i do have an excuse, sorry meant 'reason'! I've made quite a bit of work recently, but quite a bit of it has been damaged by the freezing conditions. The sub zero temperatures arrived before the pottery had dried and unfortunately a lot of it split as the water in the clay froze. I did manage to salvage about half of the work which I'm due to glaze fire tomorrow. I'll bring it into the house in future!
I've also been doing some painting recently. Just quick still life studies in oil. I've been doing these mainly to get some confidence in the media, as I've not really done that many oil paintings before.
Tomorrow I fire the first glaze firing of 2013. Pictures to follow...