With mesh, the larger the number, the smaller and finer the particles. Green sand refers to the sand molds formed from wet sand and is sometimes referred to as clay. 2NS Sand. What is Ceramic Ceramic is heat-resistant, nonmetallic, insulators (does not conduct electricity), corrosion-resistant, hard, but brittle (like glass), inorganic solids made out of clay that has been fired to high temperature. Mixing the two gives you something in between). Used for concrete, asphalt and sewer systems. Sand casting using green sand is quick and inexpensive since the sand can be reused. I'm having to ask these strange questions because up until now the University always provided the clay, glazes, kilns and the "night trolls" to put it all together out of my sight and knowledge. Most of the times while throwing taller cylinders I walk away from the pot for about 30" come back to it, and throw the rest of the cylinder pretty well dry. Washed clean sand… Aggregates: Sand or Grog added to clay bodies to give strength and thermal shock resistance Bone dry: Ceramics that are dried completely and ready for bisque firing. Provides plants with the nutrients they need to thrive; Porous clay particles allow water to flow through and healthy bacteria to flourish in your substrate; Chemically inert and will not alter water chemistry I like the feel of sand, but others prefer grog. Clay is an amazing skin care ingredient that’s been used by ancient civilizations for centuries, and … Both work. Posted November 10, 2012. grog vs. sand in clay body updated tue 15 mar 11 : Lee Taylor on wed 9 mar 11 I have several clay body recipes that call for equal parts of sand and gr= =3D og in=3D20 the mix. :). Less Shrinkage Adding Grog … On Sunday night, I threw "tall" for the first time. The result is twofold: a clay body with sand or grog added will dry out faster than a clay body without sand or grog, because water can exit more easily (think: pure sand in the garden drains water very fast while pure clay retains water a long time. Recommended clays for Cone 10 include: Miller/Laguna 950, 900. Grogs & Sand. I'm glad I came across your post, it's extremely helpful and informative. Some clay. I think silica sand is much less abrasive, because it is a smoother particle. I how what these materials are but what difference does it make which the clay contains. Porcelain normally is very smooth.Barbara. The coarse particles open the green clay body to allow gases to escape. Is there so= =3D me=3D20 Mix a small amount of sand, crushed shells or grog (crushed pottery) into your clay. Thanks for the info. All of it is a learning process. Manche mögen ja so ein Brett am Fuß – auf jeden Fall gibt er jede Menge Sicherheit! Thanks for having the info I wanted! I've been having problems with some of my throwing platters. That way their customers are sure to find something they like. One of my pieces, that took me months to build and refine, finally fell apart. You don't need grog or sand to throw tall pots. (I also do welded art, which also allows me to build strange tools for my pottery). My fuzzy understanding it that grog is better and less abrasive on your hands. Less than 7% sand to clay is a good rule of thumb. When I want to make the occasional larger piece, I've got a supply of fine white grog in my studio--I just throw a handful on the wedging table and wedge it in to that chunk of clay I'll be using to make the larger piece. "Ground fired body added to clays to provide a proportion of already fired and often refractory material. Modern computer controlled electric kilns use a prolonged heating stage at 200 degrees F. This is just … Secondly, adding sand or grog makes the clay body more able to “stand up:” higher pot walls can be thrown without collapse, therefore larger pieces can be created. This quality is known as clay’s plasticity. Since it is not clay, grog does not shrink as clay does. You'll find that many companies offer some clay bodies that use sand, and some that use grog, and some that use both. Similar to beach sand. I want to get a white cone 6 clay that is good for throwing tall stuff. I like the definitive responses of yes both sand and grog, whatever you like that works for you;), it all depends on whether it's a sunny day or your foot itches:o. I too use a heat gun and have built a centering device that will let me quickly and easily center 20+ pounds of stiff clay. Then again too, I am not trying to throw 15 large pots a day, usually limited to 4-5 when doing them. Laguna Clay Co. for example has some very smooth clay bodies and some very "toothy" bodies (with lots of grog). But since it’s essentially ground up silica, an ingredient in clay and glaze, adding too much can cause fit uses between the clay body and glaze. This acts as a tempering agent and gives your pottery strength. Gespielt hab ich in dem Schuh ca. The glaze still fits, everything's still smooth, no cracking or warping. In general, sand is slightly acidic while clay is more on the alkaline side. Secondly, because the grog creates a more porous composition, clay with grog dries more evenly. The grog in this mix really helps the nozzle 'bite' into the side of the tube and resist blowout. The downside is that the sand is a soft mold and can collapse or shift during casting, leaving an unusable cast. 30 Mesh Flint Grog (fine) - weighed out. I am concerned that some clay manufacturers use sand instead of grog because it is cheaper. I've only been throwing and sculpting about a year-and-a-half now. Grog will have less issues than lots of sand in my view but some sand will be ok just not to much. Most commercial cone 6 clays are able to go those heights easily, however depending on your throwing style you may find that you have to change your bisque fire to accommodate the taller pots. All my experience (99%) comes from high fire clays, I think a better mix for throwing large is use both sand and grog, sand is silica which has its own issues with quartz inversion. My understanding is also that silica sand can be substituted for grog. Grog is very rough, with jagged edges. Sand or grog in clay is an opener. Testing, meaning: mark a six-inch flat piece before and after firing so you can tell shrinkage; weigh and then immerse the fired piece 24 hours, dry and reweigh to find out absorption %; and build something tallish with your 3% and your 7% silica bodies to see how much the silica helps against sagging, and what you're comfortable with.Barb, Thank you so much. Plant Sand—Not truly sand, as these products are usually made from iron-containing clay ground into small, sand-sized particles. Grog provides texture, both tactile and visual, along with bite for better control in forming. If you feel the pot is about to collapse dry it a little, not much, with a heat gun then continue to pull. Silt soils, 0-10% clay. Fired in oxidation, Speckled Buff falls into the tan/brown color range. Im Sommer habe ich mich doch tatsächlich nochmal hinreißen lassen ein paar Allcourts zu spielen (Babolat Propulse 3). I bought it from a potter who was not a professional at the time. I have had a heck of a time over the years struggling with sand and grog. I think a better mix for throwing large is use both sand and grog. Powered by Invision Community. I would mix up some at 3% and some at 7% and test them before doing anything major. The same pot could have been thrown with regular B-Mix which is a white clay for cone 10 or for cone 6. (Lots of potters use sand in their clay bodies - just keep in mind - all those grains of quartz will go through the quartz inversion at . Grog adds structural strength to hand-built and thrown pottery during shaping, although it can … I used to do a bit and wish I could have done more. It's personal preference. Sort By: Quick view Compare Add to Cart. Without knowing it, problems I’ve wrestled with for years such as “bumpy” clay and glazes, and ware cracking, have originated from trouble with these two clay components. The clay is a stiff, sticky fine-grained earth, whereas sand is a loose granular substance. When heated to high temperatures, clay also partially melts, resulting in the tight, hard, rock-like substance known as ceramic material. I love it and tried to recall some pottery terms so I found you. Bingo! Potting soil also allows plenty of oxygen to reach the roots. Fine grog is smaller particles. Low Fire Cone 06-04: Miller/Laguna 10G, 20G, 26, Standard Clays … I had to after having spiral cracks in my pots that went from top to bottom. It all comes down to the preferences of their customers, and the personal preferences of their people formulating the bodies. (vase type...with grog...) How she did it without lacerating her hands I will never know. Grog: A sand-like substance that is added to a claybody to add workability, strength and helps to reduce shrinkage of the clay. This prevents defects such as cracking, crows feet patterning, and lamination. Quick view Compare Add to Cart. April 3, 2012 in Clay and Glaze Chemistry. In dry conditions they can become hard and difficult to till. Let me rephrase my original question. Clay: Fine-grained earth … It's usually highly cleaned, because cement people have worse problems than potters if the sand is adulterated with stuff like salt (a la beach sand) or feldspar.Great idea, to check for alternate suppliers, yesssss!Just note that grog will absorb water & sand will not--resulting in slightly different throwing (or handbuilding) properties.Barb, Hi There,Just read your very helpfull post on sand versus grog,thanks.I live by the beach in Irelands East coast.I have tons of lovely earthenware clay all about me which I just cannot resist using in spite of the white calcium or feldspar?I make large-ish sculptural pieces which I paint(glazes pop of course) I just love its sea smell and its real earthy feel,smooth as chocolate....Anyhow I welcome the idea of using silica sand.Is this the same as childrens playsand?that would be a lovely coincidence,as I use this in my Art and play Therapy work.Question;how much sand should I use?.I read somewhere 7% dry weight,.Any advice?Daniel, Daniel--Silica sand is children's sandbox sand, or construction sand. You may find there are different sizes of grain available to buy, or you may not. I'm going to have to try grog in my mix. The teacher had been telling me that the clay needed more grog in order to avoid problems with larger pieces but I loved how smooth this white clay was. Grog is commonly either sand or fired clay which has been crushed and sized. sand is silica which has its own issues with quartz inversion. Therefore, its presence in clay reduces the overall shrinkage rate of the clay; more grog = less shrinkage, less grog = more shrinkage. Benefits. Appreciate the good info and Hope to use your advice soon. Some people will call throwing tall 15" others 20" and so forth. Cone 6 bodies are in between. Clay in the Potter's Hands: Musings of a Wildenhain Potter. Less Cracking Grog makes the Clay Sculpture less likely to crack. It is Laguna's B-Mix Woodfire. Used for masonry, under swimming pools, sand boxes, and volleyball courts.. Bedding Sand. Grog is not necessary, although it does improve the workability of the clay, plus reduces shrinkage, cracking and warping. As well as improving drying, it can also improve drying shrinkage. Clay body specifically formulated by request from Midwest and Eastern U.S. potters. Which type of clay has the most grog earthenware, stoneware, or porcelain. Lacking the microscopic size and shape of clay particles, grog decreases the plasticity of the clay body, but it does have a beneficial effect on shrinkage. However the particle shape should be taken into account. I use a heat gun on plate rims when laying them out, but prefer to let the pot sit spinning for more even stiffening than the heat gun. Washed clean sand. 2 Wochen inklusive Training und einigen Wettkampfspielen. I guess in the long run it depends on what you call tall? This topic is now archived and is closed to further replies. The sand mold is in an uncured state as the metal is being poured. Potting soil is made up of equal parts of silt, clay and sand. Clay- < 0.0002 mm Silt- 0.02 to 0.002mm Sand- 2 to 0.02mm Gravel- > 2mm * Clay is very small in size and thus doesn’t leave any space gap between the particles which makes them very dense. Sculptured Clays tend to have much more sand and grog. For tiles fire this body to cone 10 to fully vitrify. Sand has the same forming properties of grog in the greenware stage. They always seem to crack around the outer rim before I build my wall that is only about 2 inches tall. Also, a heat gun helps. Often used in clay bodies instead of grog or to augment grog. I have thrown cylinders the length of my arm with an off white clay by Standard that has fine grog in it. Compacts well. Earthenware (low-fire) Sculpture clays exist that are super groggy. docweathers, Standard Clays 108. ), I do know that low fire throwing bodies(used to) not throw as well as high fire bodies, They may have fixed that by now. sand vs grog updated wed 8 oct 03 : Paul on wed 1 oct 03 Is there any risks involved in using silica sand instead of grog in a stoneware body? The addition of grog or sand may permit a plastic clay to stand up taller without slumping, thus making it more workable even though it is not more plastic. By The finer the particles are, the stronger and more dense the clay … Classes of Clay . The grog also helps the nozzle resist erosion of the hole during motor burn, whereas without the grog, the clay can wear away some and the nozzle aperture (hole) opens up some during the motor burn, which reduces pressure and thrust. I used a cone 6 white clay from Continental Clay. I was thinking about adding Raku in with my bmix to see if that would help solve my problem. These clays are designed to accommodate large handbuilt, wheel thrown or sculpted projects. Der Schuh selbst ist vielleicht noch steifer als er auf den ersten Blick aussieht, aber das ist nicht der Punkt. You can make just about anything with any clay body, but grog makes it more forgiving. Washed screened sand, does not compact well. It consists of particles of rock and hard minerals, such as silicon dioxide. Compared to sand particles, which are generally round, clay particles are thin, flat and covered with tiny plates. Clay differs from inelastic earth and fine sand because of its ability, when wetted with the proper amount of water, to form a cohesive mass and to retain its shape when molded. I just kept going thinking that it was going to be ok and that I'd repair any crack that appeared, big mistake lol. Effect on herbs: the pH level is correlated with the capability of soil to hold and release nutrients to plants. Less than 7% silt. 573C on the way down during bisque and glaze fire cooling.) Mason Sand. You are very helpful.Sara. Sculpture claybodies contain significant amounts of sand and grog in various mesh sizes and are formulated for a low rate of shrinkage. Sculpting clay … The color palette is perhaps best described as 'desert' or 'Southwest'. Silica sand particles can be rounded or angular, the latter being more suited to clay bodies. However, the process … It allows the moisture to steam out (to escape easier) at the early stages of heating. It should say on the bag "100% silica sand." Are there any other reasons grog is used in clay? I would like to hear if anyone has tried both and found a considerable difference between the two. These clays containing grog are much more abraisive and=3D20 unpleasant to work with. These soils differ from sand soils by having a greater tendency to form a crust, which is often very hard. Quick view Compare Add to Cart. A thick-walled construction was required in order for the vessel to stand, in an unfired state, without collapsing during the air-drying process in preparation for firing. The only thing i have heard is that it could have an affect on expansion but i don't know to what extent this would be a problem. Low in sand and grog content, speckled buff is smooth textured. An excellent throwing body. However, the very high thermal expansion behavior of the quartz grog should not be ignored. Standard Clays: 547, 420, 239. As nouns the difference between clay and sand is that clay is a mineral substance made up of small crystals of silica and alumina, that is ductile when moist; the material of pre-fired ceramics while sand is (label) rock that is ground more finely than gravel, but is not as fine as silt (more formally, see ), forming beaches and deserts and also used in construction. The large, relatively stable sand-particle size increases soil aeration, improves drainage in tight soils and creates plant-growth supporting qualities, or tilt.The particle size of course sand r… For example, a 100 mesh grog is coarser than a 200 mesh. Potting soil drains quickly, while holding onto just enough moisture to encourage plant growth. Because of this tendency to encourage clay to dry more evenly, adding grog to a clay body can help quite a bit to prevent cracking. However, they are generally easy to till and can store considerable amounts … Woodland potters attempted to remedy the high shrinkage by using large amounts (up to 33%) of coarse sand and/or grog temper in their efforts to render the clay usable for vessel construction. Key difference: Clay and Sand differ in their particle size. thanks, … You could also increase your project's strength by mixing in a little bit of wet, shredded paper. Moreover, their vessel shapes were necessarily confined to either a flat or conical-bottomed vessel. Grog is available in in various mesh sizes. Why would a clay manufacture choose to use grog versus sand? After firing, clay pieces will pop off as the pieces of lime contaminants expand by absorbing atmospheric moisture. I have a pot that is beautifully thrown. Difference between Clay and Sand. It's their B-Clay. You can add anywhere from 10% Grog to 50% depending on the quality and look you may want. The silt is full of nutrients for the plants. Grog is used in pottery and sculpture to add a gritty, rustic texture called "tooth"; it reduces shrinkage and aids even drying. Grogs & Sand. Sand must not include any limestone. The size of the particles in the clay determines the size of the shrinkage and clay with grog in has much larger particles. But I will admit that it took 4 tries to get anywhere close to this height. I was amazed that she could throw such a large piece about 12 inches high and about 5-6 inches across at its greatest diameter. As the clay dries, the fibers of the paper will help hold it together. Cone 5-6: Miller/Laguna Clays 45, 66, 75. Is this true and what else is different between the effect of these two additives to add "tooth"? grog vs sand in cone 6 clay for tall stuff, (Lots of potters use sand in their clay bodies - just keep in mind -. 10 Mesh Flint Grog (coarse) - weighed out $1.25. The grog and sand make the Clay better for a decorative item than a functional one. They are the largest type of soil particles, where each particle is visible to naked eye. The bottle below is 19 inches high with very thin walls. Very fine, no small stones, ¼ inch minus. In simple terms, clay is a special kind of earth which is made by the decomposition of rocks through the action of weathering. While drying shrinkage, it can help reduce firing … The grog is eating my fingernails! Learn Colors with Yogurt Surprise Kinetic Sand vs Clay Slime vs SiIly Putty Learn the Colors: Orange, Pink, Yellow, Blue, Red, Green, Black, Cyan, Purple. Ceramic Arts Network If they are over-tilled, they can become compact and this decreases their ability to infiltrate water in wet periods. Clay, sand and silt varies with their particle size. Is this an issue in buying moist clay? I understand that it needs to be fortified with sand or grog. If too hard you may have to use too much water to center. (Lots of potters use sand in their clay bodies - just keep in mind -, all those grains of quartz will go through the quartz inversion at, 573C on the way down during bisque and glaze fire cooling. Consider using clay that is as hard as you can center quickly. It has no grog or sand. The ware is fragile at this stage, and still considered to be greenware. I found a local building supply place that sells silica sand for about $40/ton, that sure beats $20/bag!Check out quarries if you are having trouble finding silica sand in bulk.Also even if you want it bagged, the quarry is always going to be waaaay cheaper than getting this type of material from a ceramic supply place.I've been dabbling in clay architecture and after working with some highly engineered mixes, I have come back to just a basic mix of sifted local clay and silica sand. By using this site, you agree to our Terms of Use. Adding Grog to your clay is a good choice for several reasons. Stoneware usually has the most grog, although different clay "bodies" in the stoneware category have differing amounts of grog. I found it to be quite smooth and much different to work with than the brown clay that I use, but once you get used to the characteristics quite nice. Nathan:Silica sand (especially at that price) would indeed be a good substitute for grog, if you can get the size particle you want. She is a very skilled individual. It is most extensively used construction material. Experiment with ratios of sand to clay. Less than 3% silt. All ceramics shrink by around 6 percent when they are drying; this when the water leaves the clay. 02 of 07. Ceramic: Objects made from earthy materials and hardened by heat to at least 1085ºF/573ºC (quartz inversion).