Clay - COSHH

When working with clay there are a lot of health and safety regulations 

Clay can produce silica dust this dust is hazardous and can cause a serious lung disease called silicosis which can cause permanent disability and early death. This dust is so fine that it is invisible under normal lighting, being so fine this dust can get into the deepest part of your lungs. Thing such as drips and spills that dry are a source of the dust.

Areas should always be washed with damp cloths or mops to avoid the dust lifting up into the air and rooms should always be well ventilated. If your clothes get clay and slip on them and then dry out this can also be a source of dust exposure. So too keep the number of dust sources down don't let clay or slip dry out.

Handling used molds can also create dust, avoid hand sweeping dust or cleaning areas with your hands, use damp cloths to wipe into a bin or clean up. When using tools ensure your tools are clean and don't have old dry clay or slip stuck of them. also keep the work area clear of bags and uneeded items that could cause an accident.

 

-Wet clay is soft and easily workable

-Leatherhard is when the clay is half dried, it is still workable but can support itself.

-Greenware is when clay is in its most fragile state, all the water has gone from the clay at this point, the clay is now ready to fire.

- Bisque clay is clay that has been fired in a kiln, but is still porous enough to absorb water however nothing can be added to at this point and the created piece should be basically finished.

- At this stage you would glaze the clay and then it would go in for another firing in the kiln.

Three main types of firing:

• High Fire - This is mainly for functional pottery, like dishes and bowls, and is fired at approximately 2300 degrees to make the glaze harden to a hard glass coating. The entire heating and cooling process of High Fire takes about 3 days.

• Raku - This process is done in a small outdoor kiln, and the pot is heated until it glows red hot (approximately 1800 degrees) and then immediately taken out of the kiln with tongs and either burning horsehair onto it, or placing it into an enclosed area like a garbage can filled with newspaper, pine needles, sawdust, or any other type of combustible material. This process only takes an hour or so, and always comes out different.

• Pit Fire - This process involves digging a hole in the ground, placing your pots in it with wood and sawdust, and lighting it on fire. It takes about 5 or so hours to let the pots get hot enough to turn rock hard. Chemicals can be added to the sawdust to make them turn colors, like Iron Oxide, or Cobalt. These pots always come out different, and sometimes need to be fired a couple of times to achieve the type of coloration you desire.

Procion and disperse dyes

Disperse dyes.

You mix disperse dyes with water then paint them onto paper, then when it is completely dry you transfer to fabric with heat. Disperse dyes can be mixed together and can be diluted if too strong.

 
As you can see the resulting image can be quite different depending
on the strength of the dye.

Health and safety:
Keep area around heat press clear and tidy.
Let others know the heat press is turned on.
Do not leave the heat press on if nobody is in the room.
Take care when adding or removing items from the heat press as it is very hot.
Take care with clothing and hair, do not wear loose hanging clothes and have your hair back,
Make sure when you are using the press nobody is standing in the way of any levers.
Turn off by the wall when finished using.

Procion dyes.

Procion dyes are used to dye natural fabrics, for this technique you mix procion dye in with water and leave your fabric for how ever long you wish, the longer it is left in the solution the darker the fabric will go. For the dye to hold on the fabric and not wash out salt and soda ash must be added to the solution. Once the fabric has been left in the dye for however long you need for the desired outcome you simply wash it under the tap and then you can wait for it the dry or iron your fabric.

Lino printing

Lino Printing

Lino printing is a technique where you cut into a plate, which is used for the relief surface, with a sharp knife, V shaped chisel or gouge. The areas cut out will create the negative space on the print and so the raised areas will print the positive image. The plate of lino is then inked with a roller and impressed onto paper or fabric. The printing can be completed by hand or by press however both have different outcomes.



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                        Hand printed                                                                  Machine printed



The hand printed method gives the print an old shabby sort of look, but the machine prints picture is much more full and crisp print.

Health and Safety

• The lino cutting tools are really sharp and easily cut you, remember to cut away from yourself and any other people around you.
• If you do cut yourself make sure you attend to it immediately these tools can sometimes cut a lot deeper than you think, the tools also are most likely dirty and so you must clean the wound.
• Do not leave your area messy and unorganized you could cause yourself or other people injuries.
• If using a press to print your lino then be careful and aware when using it, and don't try and use the press if it is too difficult as you can injure your back and muscles.