Gilliatt Colored (Casting) Slips

Transcription

1 Colored (Casting) Slips I use these slips as both a decorative colored slip on my wheel-thrown pots as well as a casting slip for my mold-made pots. It s very important to always test for fit when using one or more slip or clay body in combination. If the different slips or clays have different rates of shrinkage, they will crack in the glaze firing. For my thrown work, I use Laguna s cone 10 Babu porcelain and the colored slips fit great on top of this clay. With the slip-cast work, I ve had to test the different colored slips in combination to make sure they fit. For example, when adding mason stain to a slip, the more mason stain the brighter the color but the higher the shrinkage rate. You can always make slip out of your existing clay body. Here is the general recipe. 10 lbs dry clay recipe (this can be bone-dry scraps) +4 lbs water +13 g sodium silicate This will yield approximately one gallon of slip 5,4,3,2,13 Porcelain casting Slip Grolleg 5 lbs Water 4 lbs Custer 3 lbs Flint 2 lbs Sodium Silicate 13 grams Colored slip additions: For Black slip add 100g Mason Stain 6600 For Pink slip add 120g Mason Stain 6020 For Yellow slip add 120g Mason Stain 6450 For Blue slip add 80g Mason Stain 6376 This Slip is vitreous at both Cone 10 and Cone 6

2 Glazes Pier Clear Adjusted Cone 10 Custer 275 Silica 240 Grolleg 200 Wollastonite Zircopax 1% = 97.5 Vee gum 1.5% = This glaze is clear in oxidation and an ice celadon in reduction Color additions: For purple (oxidation) sky blue (reduction) Add 4% Mason Stain 6332 For yellow (oxidation) Add 4% Mason Stain 6450 For black (oxidation) Add 4% Mason Stain 6600 Bohl s Satin White Cone 10 Custer 4300 Gerstley Borate 1200 Dolomite 700 Talc 1400 EPK 500 Flint ,000 Color additions: For baby blue Add 4% Mason Stain 6376

3 Stickers, Tape, & Vinyl Cutters In addition to wax, I use a variety of adhesive papers as glaze resist for decorating my pots; namely stickers, masking tape, and full-page shaping labels. All of these supplies can easily be found at local office supply stores and on-line (Wal-Mart, Office Max, U- Line.) With the full-page shipping labels I use a small vinyl cutter to create my own shapes for stickers. (You can also use the shipping labels to create your own stickers by hand with a pair of scissors.) The product I use is a digita cutter made by the Silhouette company called the Silhouette SD. It is roughly the size of a small printer and is both Mac and PC compatible. The cutter comes with its own software and stock shapes and is also compatible with Adobe Illustrator. When using stickers and tape as a glaze resist, it is important to peel them off after the glaze has been applied. The stickers and tape do burn off in the glaze firing but they will leave behind a (dis)coloration that may or may not be desired. When I glaze, I typically put the pieces under a fan once they have been dipped in glaze. This dries the paper part of the sticker making them easier to peel off. If I m not strapped for time then I ll just peel off all of the stickers the next day. Links to digital cutters

4 - Laser Transfer Decals If you ve ever used a computer and a printer to print anything then you already know how to make your own Laser Transfer Decals. All you need is a Laser printer and Water Slide Decal paper. Old HP laser printers work great. Most of the images I use I draw myself on the computer. You can also use original photography, text, found images, scanned images or drawings. The iron oxide contained in the toner of laser printers is what makes this method work as a ceramic process. This process will not work with ink jet printers!!! Applying the Decals After the glaze firing, sand any exposed areas of bare clay with 400-grit sandpaper for a smooth finish. Cut out the decal you wish to use. Don t worry about cutting away negative spaces, any excess material will burn away and this will make for easier application. Place the decal in room temperature water and wait for it to become fully saturated. Hold the decal onto the piece, ink side down, and slide away the paper (figure 12). The decals will still work if you don t place them ink side down, but the color may not be as strong. With the decal placed on the ware, use a sponge or rubber rib to remove any excess water and to remove any air bubbles that might be trapped under the decal. Trapped air pockets may cause the image to bubble or become distorted. Be careful not to work the decals too hard; they are thin plastic and can tear easily. Make sure there is adequate lubrication when smoothing away air pockets. For large decals, or for decals that need to curve, use a hair dryer to lightly heat the decal to make it more pliable. Firing the Decals For firing to glazed surfaces I would recommend the following temperatures. These are not tried and true temperature merely starting points. Always test. Glaze fire cone 10 - Laser transfer fire cone 04 Glaze fire cone 6 - Laser transfer fire cone 04 Glaze fire cone 04 - Laser transfer fire cone 06

5 Firing Schedule for decal firing Ra1: Ra1S: 30 min Ra2: Ra2S: 30 min 150/hr 110 F 150/hr 208 F Ra3: Ra3S: 0 min 350/hr 900 F Ra4: Ra4S: 30 min 700/hr Desired temp Printers I have used a variety of HP printers over the years including the HP 1022, HP 4L, & HP 5L. The following link is a list of all available HP laser printers. Toner cartridges that have at least 30% iron oxide will work. ljmsdsuseng.html Papers Here are links to the waterslide decal papers that I use. x-11-in.-100-sheets.html?page=1