Tuesday, January 13, 2015

Pitchers.. More, and Bigger! Decorating with slip. A summer flower!

My pitchers or jugs that I made at the beginning of last week each started with 2 kg (4.5 pounds) of clay and most were 12 to 14 inches tall. I then made a few more later in the week that used a little more clay. These pitchers are between 13 and 17 inches in height.


To make them I started with 2 kg of clay, and made the acorn shaped main part of the pitcher on the potter's wheel. These were rested for a few hours so the clay stiffened to become soft leather hard, then clay was added to the top and thrown higher on the wheel to form the neck of the pitcher. I sometimes speed this process by using a small gas torch to stiffen the clay.

The method that I used for adding the clay varied depending on what I wanted to do. On some I added a coil of clay that was then thrown higher, and others had necks that started as open ended cylinders that I threw on another wheel.

The following day handles were added to each pitcher, and in the evening of that day white slip was poured in and out of each of them, to coat the inside with an even white layer.

Slip

The white slip, or engobe, was the same as what I used in the previous post, but I will give the recipe again here,

Daniel Rhodes Engobe for damp clay. Cone 1 - 6.
Kaolin  25
Ball Clay  25
Nepheline Syenite  15
Talc  5
Silica  20
Zircopax 5
Borax  5


I add all the ingredients to water, let them sit for about an hour if I can, then sieve through 40, 60, and 80 mesh sieves. I rarely bother to go finer than 80 mesh for anything these days. I start with about 1 litre of water for every 1000 grams of dry material. I like to make the slip the day before I use it, and I might need to add a little more water to thin it to the consistency of fresh cream.


Decorating

The next morning I began decorating the outside, and I thought you might like a little glimpse of the decorating process.


I make use of an old aluminium bucket and 2 lengths of wooden dowel when doing slipping or glazing the outside of a large pot. The bucket sits on top of a wheel so I can turn the whole thing around when I need to. I found it was handy to tape or rubber band the dowels together at one end so that they could not spread apart, then I loosely clamped the other ends with the metal handle of the bucket.

I find it useful to have a second bucket nearby, without the wooden dowels. I can use the second bucket if I pour slip over a pot that I am holding, and I don't want the dowels to get in my way!

Here Goes....!

I was not able to photograph the first step in decorating the outside of a pitcher, as I really had my hands full, but I think that this sequence of photos should give you the idea. 

This pitcher is just over 17 inches tall, and fairly soft, so I have to handle it quite gently. I don't feel confident that I can hold it upside down and pour slip over it in one operation, and I do not have a deep bucket full of several gallons of slip to dunk the whole thing in, so I tackle this one in two steps.

First, I will pick this one up (not by the handle) and hold it over a bucket. I start by holding the pitcher on its side and somewhat head down over the bucket. The handle is to the left at the beginning of this operation. I pour slip around the top few inches of the pitcher, then I roll the pitcher around so the handle is now on the right hand side. Then I pour around the rest of the top, and continue over the handle and the side of the pitcher that is under the handle. Then the pitcher is placed on the dowels over a bucket ready for step two...

Here is the pitcher after stage one of the pouring of slip. The handle and the top part of the pitcher are all now covered in white slip.
Next, the lower two thirds of the pitcher are covered. I like to pour slip with an old metal milk saucepan, the sort that has little pouring lips on each side. I am rotating the pitcher as I pour.
Hey Presto... All done!  

The pitcher is put in a safe place to dry. Once it is dry enough to touch I will sometimes help the base of something large like this to dry by standing it on an off-cut of drywall (plasterboard or Gib board), you could also use a plaster slab for this.

 

A Summer Flower!

Whilst many of you are enjoying winter, we are trudging our way through the warm and rather dry months of summer here....

I thought I would share a bit of summer with you by posting a photo of a lovely hydrangea flower that I took a few evenings ago.

10 comments:

Michèle Hastings said...

Thank you for sharing your slip process on the jugs... and after the cold spell we have had I really appreciate your flowers blooming!

Melissa Rohrer said...

I really like those tall pitchers. I have not yet tried adding a collar/coil of clay to a form. You may have inspired me to give it a try!

Arkansas Patti said...

I keep forgetting we are in opposite seasons. Enjoy that pretty warmth and lovely color.
I am loving your slender looking vases very much but still have a soft spot for the pot bellied ones. Both however display such gracefulness.

Peter said...

Hi Michèle,
Thank you for your "Thank you"! I thought it was about time I put a bit more about the process on the blog, and thought that flowers for those of you in the "frozen North" would bring some cheer!

Hi Melissa,
Do try adding a coil or a collar to a form, it is really fun to do and opens up all sorts of new possibilities. It is a more "gentle" approach to adding to a form than the 2 part method of throwing. The coil of clay can be quite thick, or thin, depending on how thick the wall of the pot is that it is being joined to. A small gas torch can certainly speed up the operation, by firming up the clay wall just prior to joining more clay.

You will probably need to scratch the area that will receive the coil and do a very light smear of water or slip over it, but the main thing is to avoid using lots of slip when joining the coil to the pot, as it will often make things stretch and move when the new clay is thrown higher.

I find that throwing against a sponge is a useful thing when persuading the new clay to join without lumps and bumps or wrinkles! There is probably a lot of useful video stuff online already, but I might get Laura to take some photos when I next do some wheel work.

Have fun!

Hi Patti,
Good to hear from you, I hope you are feeling a bit better. Thank you for your encouragement regarding the pots. There are lots of similarities between pots and human form, I think that consciously, or unconsciously, the potter is celebrating that humanity when making pots. Tall or pot bellied pots can be graceful, and I think it is down to their posture, how they stand, and their attitude and spirit... which is exactly the case if they were human!

Anonymous said...

Pitchers,Jugs, or vases... take your pick!
The first could lead to an interesting and confusing conversation with a baseball fan... but never mind, I'll leave it to P.G.Wodehouse addicts' inventiveness!
Whatever else you call them, they're unique creations and beautiful in my eyes. I'm looking forward to seeing them after being fired, and just hoping they don't lose the 'purity' that white conveys.

Peter said...

Hello Anonymous (Dad!!),
Pitchers... baseball...mmmm, it would be confusing to be at the receiving end of a jug doing 90 mph!
Glazes are currently "under construction" for the jugs. I'll do some clear, but have some alkaline copper glazes that will be tested over slip soon!

Anna said...

Hi Peter love seeing the process of others making techniques.. oh for a second wheel to throw that extra 'coil' to add.
Your bats are very thin, what material are they made from? Hope you don't mind me sharing over to my Facebook page, Anna's Aussie Ceramics. Aussie including our NZ neighbours :)

Peter said...

Hi Anna,
Good to hear from you. I do find having a second wheel in the studio is very useful... it doesn't have to be a particularly good wheel, but just something that can do little things when needed.

The bats in the photo are made from tempered hardboard (or masonite as it is called in some parts of the world). The "tempered" bit is important, as ordinary hardboard does not stand up to water all that well, but the tempered variety has been coated with linseed oil and baked when it is manufactured and is waterproof. The tempered hardboard sometimes comes with a texture on one side (which I find annoying), so I try to get the sort that is smooth both sides.

You are most welcome to share the blog on your Facebook page.

Linda Starr said...

beautiful tall pieces, wondering if all that slip ever makes the pieces fall apart with absorbing the slip?

love the hydrangea

Peter said...

Hi Linda,
I confess to have been a bit scared of pouring slip into or over a large or tall pot, and have only just started doing it with more confidence. I think the best time to do it is when the pot is leather hard. I have tried it on dry pots, and sometimes lose them, with the pot splitting. There are techniques to make slip application at the dry stage more likely to succeed, but the leather hard stage seems much easier to me. This also works best for me on earthenware clay. I have more failures on my stoneware. I have been inspired and encouraged by videos that Doug Fitch has on his site www.slipware.blogspot.com
Doug decorates his earthenware pots with slip, and really pours it on!