Category: Workshops

I don’t know what I can write about actually throwing as it seems to be a skill that is largely down to individual preferences/ways of working, so until I have tried lots of ways of working, I will leave that bit out! Things I learned:

You need a clay which is plastic (or flexible!)

The clay needs to be ‘wedged’ and portioned before working.

It is essential that the clay is centred before trying to pull up the sides, otherwise it will be thicker on one side that the other, twist easily and just generally make a rubbish pot!

The base should be 0.5 – 1cm thich – check with your thumb tip or a needle.

when ‘pulling up’, you aren’t actually pulling – you are squeezing your fingers together, keeping them the same distance apart and moving them slowly upwards. Make sure you don’t pull your hands towards your body as you lift – this will also ruin your pot!

To get the pot off, use the wooden tool to create a little dent for the wire to go into, then splash water on your wheel in front of the pot to enable it to slide, push the wire down against the wheel behind your pot and move it towards you, keeping it as flush to the wheel as you can. Do this in one movement – don’t wire twice. gently move onto a board and cover in plastic to dry slowly.

To fuse glass, first you need to cut it. Clean glass with methylated spirits – a glass cutter will slide on any greasy spots and won’t cut a clean line. Draw your template & place it underneath your glass. Hold the glass cutter vertically and place it on the glass above the line you want to cut, moving the ruler or guide to the glass cutter, otherwise you won’t be lined up properly. In one single movement, press down hard & follow the line – it shoudl sound like fingernails down a blackboard! To break the glass, use the blue pliers, making sure the red diamond is on the top so the glass snaps downwards , not up!  Smooth the edges with either a sanding stone under water in a bucket or on the sanding machine.

Either paint on your design, or make whatever you are going to trap in the glass. Copper will discolour and go red, other wire will go black. Organic materials can be dipped in paint, then trapped – the organic material will burn away, but the paint will remain. Make sure paint is dry before positioning the top glass – wet paint will cause steam, bubbling and cracking in the kiln.

Check workshop guides on moodle for firing temperatures and times.

Find a screen & check the board to make sure it isn’t reserved by anyone. Clean it with the squirty spray & brush in the wet room, blast it with the medium setting on the pressure washer (not the highest setting as it will tear through the screen!) Make sure every trace of the green stuff is removed.

Write your name & the date on the board next to the number screen you have. It will be yours for 3 weeks.

Put fresh photo emulsion on the screen using the trough – make sure you use the right size trough – should be between 1 & 2 cm in from frame. Hold trough against screen 1 – 2 cm from the bottom & slowly tip until the emulsion is in contact with the screen all the way along. at this angle, slowly and smoothly pull the trough up the screen until you are 1 – 2 cm from the top & tilt back so the fluid is no longer in contact with the screen. Pour any remaining fluid back in bottle & clean trough & side bits thoroughly in sink. Allow screen to dry in the drying cabinets for 40 mins.

In the meantime, draw your design on normal paper, tracing paper or the special screen printing plastic film with a smooth & a rough side. Use indian ink or super-saturated black permanent markers only – if you don’t use good enough quality ink, it will be patchy.

Place your design in the exposure unit, position your screen over the top, set the timer for 4 mins & once exposed, rinse in the wet room again on the medium setting, both sides. Dry completely – if you can’t leave it overnight then dry it by the heaters but make sure it is completely dry.

Clamp screen in press, use the brown plastic tape to cover the edges & any patches where the green fluid has missed. Mix your paint – half acrylic, half screen printing medium. Blob it on your screen about an inch above your image making sure you use enough to pull a few prints. Switch the vacuum on to make sure your screen is in contact with the surface you’re printing on & do a trial pull on the acetate sheet – this will also be used as a placement guide when printing on paper. Pull at the angle shown in the photo below – not straight up or too horizontal – this angle will give a good print.

Make sure you clean all the equipment thoroughly after use. The screen, once rinsed of all screen printing paint, can be left for the next user to clean the green stuff off – don’t forget to wipe your name off the board.

This method is suitable for stoneware and teracotta clay. To decorate clay with slip, the clay should be damp or leather hard – if it is dry, the slip won’t bond & it will crack off. The recipes for mixing the coloured slips are on the wall by the sink in the glaze room. There are many techniques you can use to decorate with slip – painting, sgraffito (scratching), sponging, dragging, swirling colours together, all sorts! If layering, allow each layer to dry a bit before applying the next, especially if working on a 3d piece as the moisture from the slip will re-soften the leather hard clay & it may collapse.

Best resource for additional information/tutorials/advanced techniques:

http://www.alternativephotography.com/cyanotype-classic-process/

First you need to mix 25g Ferric Ammonium Citrate with 100ml distilled water, separately mix 10g Potassium Ferricyanide with 100ml distilled water, then mix the 2 solutions together 50:50. This can be kept in a dark brown bottle and kept in the dark but it will not last long, so needs to be used quickly. A bottle of ready-mixed CYAN is always on hand in the print room.

You can print on any organic material – paper, natural fabrics, wood, bone…

You can either print using physical objects such as leaves or scissors or anything, or you can print from a digital image turned into a negative. To do this, open your digital image in photoshop, make it black and white, invert the colours and print on acetate (you have to print on paper, then take to the copy shop at Uni as the general use printers don’t take acetate.)

In a dark room, paint the chemical solution onto your paper/fabric/wood and leave to dry in the dark – do not expose to UV light. To paint it evenly on paper, stretch it with gum strip like watercolour paper first. You can get all sorts of interesting results by using different brushes, brushstrokes and other application methods, but aim for a thin even single coat – don’t allow it to pool or it will go a funny green colour.

Once dry, place the negative on the glass of the exposure box in reverse (i.e writing will need to read backwards when you look at it in order for it to be correct on the finished print).

Place the dried painted paper over the top, face down, then put the lid down and clamp it closed. You can have the ‘tubes’ on briefly while you arrange this, but it will affect the exposure & quality of the print, so be quick if you have to!

The exposure timer should be set to 7.30mins, then turn the cycle button to on

 

Once the exposure cycle has finished, take your print to the wet room and rinse the paper using the hose. It will have gone a green colour where light or white will appear in the final print. Again, do this as quickly as possible as the exposure to light will affect the print if you take too long about it. Make sure you rinse all of the chemicals off – no green remaining, otherwise it will all go blue (rinse especially well on fabric as the fibres hold the solution, so really rinse well!)

Once thoroughly rinsed, dry in the blotting paper in the corner

The first step in slip cast mould making is to decide how many pieces you are going to have to make the mould out of – check for existing casting lines, alternatively where are the natural circumferences, are there any bits sticking out or indentations that will make it impossible to remove the object from the plaster once it is set? Mark the lines along which the pieces of the mould will need to run, and where the clay will need to be built up to.

In my case, as I chose a spherical shape, it was best to have 2 pieces – the line needed to be around the widest circumference point. The best way to find this was marking a set square with white china marker and holding it as in the second picture, turning the vase around so that the white was left on the widest part of each ridge.

Get a board and either start building up the clay around the object up to the lines you have marked, or if the object needs to be set at a specific angle, set it in a little clay first, then build it up.

The clay will need to be  a minimum of 4cm deep at it’s thinnest points in order to ensure that the mould will be thick enough to cool the casting slip sufficiently. Don’t make it too much thicker as then it will take too long to dry.

Make a ‘spare’ to fill in any holes so that the plaster doesn’t fill the object and make it impossible to remove. This will also create a pouring hole for casting. As such, even if the object you are casting is solid, you will still need to make a spare for pouring.

If your object is circular, use a sheet of plastic  and string tied tightly with slip-knots to wrap around the clay, otherwise use cottling boards. They need to be tight in order to prevent seepage of plaster. As an added measure, always cover any joints on the outside with wet clay – you don’t want it going all over the floor.

Mix plaster according to quantities on wall chart. Always wear a mask and make sure the extractor is on when measuring plaster. Once it is in the water it’s fine – you just don’t want to breathe in the dry plaster powder. Make sure that the yellow bucket is rinsed and that you don’t ahve any flakes of set plaster floating around in it. Leave plater and water to sit for 2 – 3 minutes before stirring to ensure saturation. Stir with hands until combined to a regular consistency, but don’t agitate too much – you don’t want to trap air bubbles in it. Scrape off any bubbles from the surface as you would when cooking a broth, and throw them on the red plastic mat where they can be scraped off when dry. Once it has thickened and you can draw a figure 8 in it and see a slight trail, pour the plaster into the mould over your hand (to distribute it evenly & stop your object from being dislodged by the force). Leave for 20 minutes before removing cottling boards/plastic and string.

Flatten top with the plaster grater, turn over and remove clay and clean off with a wet sponge. I forgot to take a photo of this but, but put in ‘natches’ with a 2p piece (indentations and protrusions that will help place your mould together correctly when finished).

Soft soap the plaster, including about an inch down the sides with a small sponge, then wipe it off with a wet sponge (get a jug of water to rinse sponge). Repeat, then put a third wash of soft soap on but this time don’t rinse it off, just remove any bubbles with a dry brush.

Replace cottling boards or plastic and string, re-clamp gaps with wet clay and repeat the plaster mixing and pouring process. Et voila!

The instruction cards for the machine speed dating: