Les

See the attached file for my mixing chart. Open as an Microsoft Doc....This should work. Good luck, Les #1 Plaster Mixing.doc #1 Plaster Mixing.doc

See the attached file for my mixing chart. Open as an Excel Spread sheet....Les

Sorry about my post above. It is a nice Excel spreadsheet for mixing plaster that this system is not set up to handle. I'll try to post in a different format. Regards, Les

For a specific reply to plaster ratios & water needed: for No.1 Pottery Plaster, the ratio is about 70% water (by weight) to plaster. I have attached a chart below that I use not only for mixing, but for figuring out the right amount to use for the volume I need. The ROUGH RATIO IS 3 POUNDS PLASTER TO 1 QT OF WATER, as stated below in the chart. After I get everything set up and ready to mix, I hand strain the plaster into my mix bucket using a wire mesh food strainer. The process is quick, but gives the plaster a good chance to be absorbed by the water without creating lumps or clumps. After that, I will always mix slowly with a latex gloved hand, just to make sure all lumps have been eliminated.....Good luck on your next project. Les PLASTER MIXING CHART FOR #1 POTTERY PLASTER VOLUME WATER WATER PLASTER CREATED IN IN IN POUNDS (CU. INCHES) QUARTS POUNDS (70% CONC) ONE GALLON= 4 8.33 ONE QUART= 1 2.08 3.0 80 1.0 2.08 3.0 88 1.1 2.29 3.3 97 1.2 2.52 3.6 106 1.3 2.77 4.0 117 1.5 3.05 4.4 129 1.6 3.35 4.8 142 1.8 3.68 5.3 156 1.9 4.05 5.8 171 2.1 4.46 6.4 189 2.4 4.90 7.0 207 2.6 5.39 7.7 228 2.9 5.93 8.5 251 3.1 6.53 9.3 276 3.5 7.18 10.3 304 3.8 7.90 11.3 334 4.2 8.69 12.4 368 4.6 9.56 13.7 404 5.1 10.51 15.0 445 5.6 11.56 16.5 489 6.1 12.72 18.2 538 6.7 13.99 20.0 592 7.4 15.39 22.0 651 8.1 16.93 24.2 716 9.0 18.62 26.6 788 9.8 20.49 29.3 867 10.8 22.54 32.2 953 11.9 24.79 35.4 1049 13.1 27.27 39.0 1154 14.4 30.00 42.9 1269 15.9 33.00 47.1 1396 17.4 36.29 51.8 ROUGH RATIO IS 3 POUNDS PLASTER TO 1 QT OF WATER

Marko, Thanks for yor reply. So, I usually dry my tiles just as you suggest. I use 1/2" Sheetrock and dry for at least two weeks, slow and steady, no rush at all. By the way I'm located in the New York area and my clay is from Ceramic Supply out of Lodi, NJ. The clay is a S108 clay that fires in the C4-10 range. But, from what you're suggesting, the trick is almost entirely in the slow drying, and has very little to do with the type of clay used. I appreciate your input Marko. My thanks again, Les

Hi everyone, While teaching a class how to make plaster press molds of tiles, everyone wanted to know the best clay mix to use to prevent warping during drying and firing. I currently use a medium grog red sculpture clay for midrange firing. More detail-- most tiles are about 4x4' and I suggest about 3/4" thickness similar to the way Grueby made their tiles 100 years ago. Does anyone have any suggestions on best clay, methods, or brands that they have used with success? Thanks, Les

Charles, Thanks for your reply-I will try casting the bisque pieces, and good idea to incorporate the reservoir into the 2 part mold. Les

Bisque firing of the tiles will burn off the mold and have no adverse effect on the them. Let the Sheetrock dry vertically and wipe the mold off with a dry cloth. The Sheetrock will look a bit stained, but can be used many times again. If you are mold sensitive, don't use this method for drying. Try a rack open on the bottom to allow even drying at the same time on both top and bottom to avoid warping. At Home Depot, Lowes, etc, in the lighting section you can find a 2'x4' light diffusing grill that is made of tiny open squares. Resting on open metal shelves, this grill gives good support for drying tiles evenly. You can cut the plastic grill to fit open metal shelving. Les

I have used PC-2 Saturation Gold many times. In the studio, I will always use it over or under another PC glaze, and some of the results are stunningly beautiful. We fire at cone 5 oxidation, and I have had some great results. Strangely, I have never gotten a great result using it alone, where it tends to come out with a dark matte metallic look, not totally gold, and not high gloss or smooth: a bit on the ugly side. I guess I haven't found the secret yet to using it by itself. I must be doing something wrong. In any event, I suggest you do a lot of testing on your clay body with the gold before actually using it. Good luck, Les

Hi Everyone, I usually throw one off pieces. But I have 2 already bisqued pieces that I would like to try to make molds from. So my questions are: 1) Should I glaze them first? 2) What mold release is the best to use in either the bisque case or the glazed case; from the point of view of both the originals and the #1 pottery plaster mold. Facts: No undercuts on the originals. Both bisqued pieces were made from Standard Clay #240, smooth white, ^6. I plan to have a 2-piece mold for the vase itself (no foot ring), and a third top piece to serve as a slip reservoir. I make great plaster, having experience with press molds for tiles. Has anyone been in this situation with good outcomes? Could you share your success, or failure, as the case may be? Any thoughts are appreciated, Les

Thank you for your fast reply. I obviously missed your post first time around. The picture looks very good.

Hi everyone. I'm currently working on some arts and crafts forms and looking for a Grueby green / Cucumber green formula that is suited for ^6 oxidation. I would appreciated any suggestions at all. I can't seem to find a clue to this formula on the internet. Anyone out there have experience in this area?? My thanks for any help that can be offered.

I also use the water based latex wax resist from Ceramic Supply. I think it does a good job. I apply it fairly fast with a clean brush. Dampen the brush first, before the first dip into the resist. Both the rim of the jar and brush will start to air dry fast, and the jar will start to form small clumps from exposure to the air, so I suggest pouring off what you think you will need into a small plastic cup, then clean the rim of the supply jar with a sponge and reseal it quickly. Keep your brush moving, and add a bit of water and remix if your cup starts to thicken. I would advise disposal of the cup and its remains after use. Do not pour back into supply jar (hopefully you wont have too much left). Also, this may be obvious, but try to do a lot of pieces at once. Clean the brush with soap and warm water after use.

I have used Amaco's Bisque Fix and can verify it works very well. I have even used it to repair green ware by mixing it with a small amount of slip for a color match with darker clays. It dries rock hard and fires well. Just follow the instructions, and do not sand or inhale. Use this link to view: http://www.amaco.com/shop/product-322-amaco-bisque-fix.html