Thursday, August 28, 2014

July Hints of the Week

July 6th Hint of the Week
This interesting information from Amaco.com
1 cup takes about 1 pound of clay. 1 pint of glaze will glaze 12 cups
1 mug will take about 1 ½ pounds of clay. 1 pint of glaze will glaze 8 cups
1 bowl will take about 2 pounds of clay. 1 pint of glaze will glaze 8 bowls

These are some more tips from the Big Ceramic Store (copyright 2003, Cindi Anderson, www.bigceramicstore.com):
 

To keep a piece from sagging while coil building or hand building, you are "supposed" to only build so far, then stop and let it firm up before you continue. But if you are impatient like me, a great solution is Duct Tape! Wrap it all around the piece so it sticks to itself (it won't stick to the clay.) This keeps the form from bulging so you can continue working.
 

I am always looking for materials to make molds from. A unique method I saw recently was to use hard foam insulation board from the hardware store (the stuff that comes in 4'x8' sheets, usually 1" thick, and is often pink). You can use a utility knife to cut out shapes to use as slump molds. I am going to use this method to make some square plates.
Another method works great for making plates, trays, etc. Find a block of wood (square or rectangular.) Cut a piece of clay larger than the wood. Put the clay on a large piece of upholstery foam. Take your block of wood and press down in the center of the clay. The sides will come up and make nice rims. This looks really great if you impress the rim with stamps before pressing in the center.
 

By the way, if you don't have any upholstery foam laying around, get some! It is great for cushioning work while you clean and trim bottoms, so you don't damage the rims. You can often get free scraps from upholsterers.
 

If you like to stamp, look for interesting textured buttons at fabric stores and flea markets. You can add handles by hot gluing thread spools onto the back, or pieces of thick irrigation tubing cut about 1" long.
 

Another great idea I saw is to tape a small level onto a fettling knife. This way you can be sure you are making straight, level cuts

July 14th Hint of the Week
What can I do if my clay is too dry?

It's not totally dry, but too stiff to work with. Use the end of a broomstick, a wooden spoon, or even a large screwdriver to poke holes in the clay, almost all the way through (leave about an inch at the bottom.) Fill the holes with water. Come back in a day or two and wedge the clay up. It will have absorbed the water and be nice and moist! An alternative method is to cut the clay into slices, soak them in water, then wedge. Or, take a soaking wet towel and wrap the clay with it. Place the whole thing inside the plastic bag. A couple days later, voila! Remember it is important to wedge clay especially when it has been rehydrated, to even out the moist and dry spots. Otherwise you will have difficult throwing, and pieces might warp as they dry. You can also put it in a bucket of water for about a week and dump it in the wet reclaim for pugging.



July 21st Hint of the Week
How to Re-Glaze a Piece
copyright 2000, Cindi Anderson, www.bigceramicstore.com

First, note that this process is never predictable. In most cases you can make a new piece in less time than you can spend re-glazing it, with much more predictable results. But sometimes there is that piece you can't part with and really want to re-glaze. Here are some things you can try to increase your success rate. The goal, of course, is to get the new glaze to stick to the old glaze.

· Spray the piece with spray starch, let dry, then reglaze.

· Spray the piece with sticky hairspray (usually the cheapest you can find), dry, reglaze.

· Heat the piece first, with a heat gun or in the oven or kiln.

· Brush white (Elmer's) glue on, let dry, reglaze.

· Microwave the piece for 30 seconds. (Some potters say this makes a huge difference, and the piece doesn't need to actually get or stay hot)

· Add some suspension agent to the glaze (CMC gum or Bentonite.)

· Add some detergent / shampoo to the glaze (baby shampoo is good because it doesn't foam)

· To improve your odds further, wash the pot first with ammonia or detergent, wearing rubber gloves, and don't touch it. The oils from your fingers can prevent glaze from sticking. And... Don't use too much of anything. If you get the coating too thick, you may prevent adhesion instead of encouraging it.


July 27th Hint of the Week
Tip from Susan Hickman
What to do with the stack of pots you aren't using? Glue them together and make an end table or plant stand! Put the heaviest widest one on the bottom for stability or start with a plate. Then start stacking. If you have a clean fit, any epoxy, power grab or liquid nails will hold. If there are gaps, use a putty epoxy. Top with a plate, or whatever you want at the top. This one has part of a lazy Susan I found at the thrift shop. When you pick this up to move it, grab from the middle or bottom so you won't put too much stress on the glued joints. These work great for in the house or on the patio. Questions? Come talk to Susan


June Hints of the Week

June 2nd Hint of the Week
When to use Magic Water? (From Lakeside Pottery in Stamford, CT)
Magic water is used when the bond between two pieces of clay is a suspect for cracking during drying or bisque firing. Cracks can occur in the following conditions:
When one piece of clay dries faster than the other which typically occurs when it has a smaller mass or thinner than the other piece (e.g., a mug handle).
When one clay piece is applied to another piece that is already a dryer leather-hard (e.g., when waiting is required for a thrown pot to harden before applying hand-built piece).

The above two conditions are more susceptible to cracking because when one piece is dryer that the other, it is therefore shrunk more than the other and will not continue to shrink uniformly after they are attached to each other, thus - creating stress.

When to use Magic Mud / Paper Clay?
Same as above with more extreme cases. It enables the joining process to be less critical and therefore one can build more spontaneously as well as build wet clay on dryer clay. Stress cracks during drying reduce dramatically. It can also be used to connect broken bone-dry pots / sculptures. Sometimes it works fixing broken bisqued pots (needs to be re-bisqued after applying magic mud). When fixing broken bone-dry or bisqued pot, always apply more magic mud / magic slip than needed and build the layers slowly allowing the layers to dry in between applications. The excess slip can be filed down after the bisque firing.

Why does Magic Water work?
Sodium in the soda ash and the sodium silicate is a very powerful flux. The silica in the sodium silicate adds some glass-former. The water is to dissolve the soda ash (which is soluble) and therefore travels a little way into the wet clay. The sodium silicate is sticky and dries really hard and faster than the clay does. The end result is that the Magic Water makes a sticky layer of almost-glaze that soaks into the surrounding clay and dries hard. Thus, cracks are prevented in the drying and the bond is stronger after firing.

Why does Magic Mud /Paper Clay work?
In addition to the reasons mention above (Magic Water), the paper fiber will bond the two pieces of clay better and resist stress more effectively during the clay drying / shrinking process (has no effect during firing).

[*We make Magic Water for you at the Clay Arts Guild. It is in containers in the high fire glaze room. Just fill your own container with what you need. If it is gone let us know and we’ll make more.}

How to make Magic Mud - Recipe?
Chop up 1/4 to 1/3 of a cup of either paper napkin, toilet paper, or paper towel
Add 3/4 to 2/3 of a cup of bone dry clay hammered into small pieces, or powdered. It is better to use the same clay for both, magic mud and your actual project.
Soak overnight in Magic Water poured one inch above clay and paper mixture.
Blend in electric blender
Pour off excess water
The slip created is ready for use


June 10th Hint of the Week
Plaster can be “poison” to pottery. If even a small amount of plaster inadvertently gets into your clay it can be disastrous. Plaster absorbs too much water, causing drying cracks and will probably explode or pop off chunks of clay when fired. Plaster is useful and important in ceramics for molds, wedging tables, drying wet pieces and for ware boards, etc.
It is not a good idea to use metal tools on plaster molds, wedging tables and clay bats as there is the potential to chip or scrape plaster into your clay.
 

Work with plaster away from clay and clean up the area thoroughly. Put down a plastic tarp on tables if you are working with plaster, otherwise the plaster will get into the canvas on the table. The same goes for “Alumina.”
 

We encourage the use of drywall boards to help dry clay. If you do use sheetrock, “drywall” or gypsum boards, to dry clay or for ware boards, make sure that you seal all the exposed plaster edges with tape. Otherwise you will leave loose chunks of plaster around. Be on the look-out for bare edges tape them up with Duct Tape.
 

We have large pieces of sheetrock “drywall at the guild which have been donated for member to use. There was some in the electric kiln room and in the back of Bill Ramsey’s studio against the wall to the northwest of the furnace. These are for your use and you are welcome to cut off whatever you need.
Be sure to cut sheetrock in an area where plaster won’t get into clay or on surfaces where clay will be worked.
Clean up the plaster dust when you are done and tape the exposed edges.



June 18th Hint of the Week
How to Re-Glaze a Piece (BigCeramicStore.com)
First, note that this process is never predictable. In most cases you can make a new piece in less time than you can spend re-glazing it, with much more predictable results. But sometimes there is that piece you can't part with and really want to re-glaze. Here are some things you can try to increase your success rate. The goal, of course, is to get the new glaze to stick to the old glaze.

· Spray the piece with spray starch, let dry, and then re-glaze.

· Spray the piece with sticky hairspray (usually the cheapest you can find), dry, re-glaze.

· Heat the piece first, with a heat gun or in the oven or kiln.

· Brush white (Elmer's) glue on, let dry, re-glaze.

· Microwave the piece for 30 seconds. (Some potters say this makes a huge difference, and the piece doesn't need to actually get or stay hot)

· To improve your odds further, wash the pot first with ammonia or detergent, wearing rubber gloves, and don't touch it. The oils from your fingers can prevent glaze from sticking.

· And... Don't use too much of anything. If you get the coating too thick, you may prevent adhesion instead of encouraging it.


Monday, June 9, 2014

Ever wonder...

 ...how it would feel to run 800 pounds of clay through your hands?

Ask Steve how pugging can change your life

Tuesday, May 27, 2014

May 26th Hint of the Week

Impressing Patterns in Clay from Lakeside Pottery tips, lessons and education, http://www.lakesidepottery.com.

There are many ways to get interesting patterns in your clay. Look around your house, your yard, and your kitchen, and you will start to see all kinds of things that can make good textures. Rocks, the bottom of your shoe, the wheel of a toy truck, a meat tenderizer, drawer knobs, a piece of driftwood, sea shells, leaves, pine cones, etc. The list is infinite. But here are a few additional ways to make more complex patterns. Lastly, there are various manufacturers that have off the shelf texture mats, rollers or stamps.

1. Bisque rods. Make a bunch of coils of clay. For example, a good size is 1" diameter and 8" long. The main problem with bigger diameters is the time it takes for the clay to dry before firing. But you can sit these aside and let them dry for a good long time. While the clay is still soft, carve or press patterns into it. For example, poke the end of a needle tool in to make holes. Or press the edge of a ruler in to make lines. Cover the whole surface with your pattern. After drying, bisque fire the pieces. Now you can use these rods to make patterns in wet clay. Simply roll your rod across the clay, pressing while you roll, and you can make long, continuous patterns.

2. Take wood dowels and apply patterns to them with hot glue. When the glue dries, the dowels can be rolled across the clay to make similar patterns. You could carve on the dowels too.

3. Wrap string, twine or rope around a dowel in straight or crisscross patterns. Roll over the clay.

4. Carved Linoleum. I got this idea from a potter who used to be a print maker. Linoleum was used for flooring before we had the vinyl floors of today. Linoleum is a mixture of linseed oil and cork. When heated it becomes soft so you can carve into it. Then it hardens when it dries. You can get linoleum at art supply stores. At the same time, you can buy a set of Speedball linoleum carving tools for about $7. Either draw or trace a pattern on the linoleum, then carve it out with the tools. You can use very intricate designs, such as a tree with many branches and leaves. The textures transfer very nicely to the clay.

5) Using off the shelf slab mats or texture molds

To transfer the pattern to a slab, put the pattern on the clay and press with your hands or a roller.

You can transfer the pattern to a cylinder as well. This is very cool for putting texture on thrown and altered forms. The cylinder should be stiff enough that it doesn't collapse, but soft enough to take the pattern of the clay. Place the carved piece of linoleum face up on a table, hold the cylinder sideways, and slowly roll the cylinder across the pattern. While you are rolling it across, use a smaller roller inside the cylinder, to press the side of the clay cylinder into the linoleum. The mini-roller works really well for this, or the pony roller for larger areas. They can be found on this page. http://www.bigceramicstore.com/Supplies/HandbuildingTools.htm

*** Important note: Non-porous surfaces, such as plastic, metal, etc. will stick to wet clay. This can make it difficult to get clear patterns. Therefore, the best materials for impressing are porous materials such as wood, bisque clay, and plaster. If you are using a non-porous object, try putting a thin piece of cloth between it and the clay, or a piece of Saran wrap. You can also try corn starch on the clay or texture tool. At Lakeside Pottery, they use W-D40 sprayed on non-porous texture tools. We have used cooking spray (PAM) also.

Monday, May 12, 2014

April Hints of the Week

April 6th Hint of the Week: Turntable on the Cheap

Thank you to Dennis Allen of Lebanon, Ohio! In Ceramics Arts Daily

While it’s not cast iron with ball bearings, this homemade turntable is easy to make, inexpensive, and works nearly as well. PVC plumbing flanges can be purchased at any hardware store or home center and both flanges can be purchased for about $10. Just match the inner diameter of one to the outer diameter of the other. Cut two pieces of scrap wood; the bottom piece, which will become the base, should be approximately 2 inches larger than the PVC flange and the top piece, which will become the work surface, should be cut to whatever size is appropriate for you working needs. The top piece should not be unreasonably large and not more that a few inches larger than the base. Each board should about 1 inch thick and sealed to handle wet clay. Center and screw each flange onto the wood pieces. Add a little WD-40 for lubrication and you are in business.




April 13th Hint of the Week: Some Glazing & Decorating Stuff from Pottery-Magic.com.

· Before you begin glazing always be sure to wipe your ceramic piece down with a damp sponge. This will make sure that there is no dust on your piece which could cause the glaze to pull away and leave a bare spot. Dampening helps the bisque to accept the glaze.

· If you are painting on glaze, you must paint on three flowing coats of glaze, being careful of brushstrokes which could show up in unleaded glazes or if you use less than 3 coats. Three coats of glaze will give you a solid color. Adding another glaze for the second and/or third coat will give you some interesting effects. Let each coat dry before adding a second.
Best to brush in opposite direction

· To show textured surfaces better, brush glaze on so it gets in all the cracks, then wipe off the top surface.

· To remove oxide mistakes or for making a design, use a pencil eraser. It won't smear like trying to wash the oxide off.

· When applying oxide over dry glaze, the glaze sucks the water out of your brush making it difficult to paint clean lines. To remedy this, lightly mist the glaze first with water and the oxide will flow smoothly.When glazing a thin piece, glaze the inside then wait for it to dry thoroughly before glazing the outside. Otherwise the clay will become saturated and your piece will either fall apart because it will have absorbed so much water or the glaze won't absorb and stick to the outside. It is best to at least let it dry overnight before glazing the outside.





April 20th Hint of the Week: A few words about Wood Throwing Bats (from Northstar)

We (Northstar) are not able to control the way bats are used nor the environment in which they are used. For these reasons, throwing bats carry absolutely no warranty beyond accurate drilling to accepted factory specifications (not necessarily to your wheel - section 2 and 3 below) and arrival in good condition.

If drilled for standard bat pins, every single bat in this carton was physically checked on a wheelhead supplied by the manufacturer of the wheel for which it is intended. Even such checking does not always guarantee a perfect fit, however, for several reasons:

1. Bat pins are off-the-shelf hardware items. Most American wheels use a 1/4-20 socket cap screw, which you can buy at any hardware store. The head is approximately 3/8” in diameter and industry standards allow quite a bit of variation in the diameter of the head of this screw.

2. Not all wheel manufacturers allow zero tolerance between bat pin holes. There may be several thousandths of an inch (and sometimes much more) variation from wheel to wheel from the same maker.

3. Most wheel manufacturers drill an unthreaded hole in the wheelhead to receive the bat pins, and there is always some (and sometimes a lot of) extra clearance.

If the fit is less than perfect on your wheel try these steps in order:

1. First, try loosening the wing nuts of the bat pins and moving them for a better fit.

2. Next, touch the holes of the bats slightly with a small rat-tail file (available at any hardware store). You may have to file on one side or the other of the holes.

3. Finally, if the holes appear to be located correctly but too small, either use a rat-tail file or try another set of bat pins, which could be a few thousandths smaller.

4. If the holes in the bat have gotten too big and wobbly put some clay on or around the pin.
Care of your bats

The life of all wood-derived bats (such as Masonite and Medex) can be extended by taking reasonable care of them. Always:

1. Clean them after each use.

2. Store and dry bats in a vertical position not horizontal.

3. Avoid keeping bats wet for long periods of time.

4. Avoid leaving wet pottery drying on them for extended periods. This causes the bats to wrap badly at the middle as the outside of the bat is drying and shrinking and the middle is wet longer with clay on it. As soon as pottery can be wired off do so and move the pottery to a ware board, dry wall board, or drying rack.

5. Avoid flexing or bending them when they are wet.

6. Warped bats can usually be flattened by drying them in a stack with weight on them. If you wet them and put them between pieces of drywall or plaster bats, with weight on them, they’ll usually flatten back out too.

7. Reversing them each time you use them (flipping them over) is the single most important thing you can do to extend the life of your bats.

8. Do not use a tools such as a trimming tool to scrap dry clay off your bat as it destroys the surface and leave it rough. Soak the clay to loosen it and then remove clay.

(Some minor edits for clarity by Big Ceramic Store and the Guild)

Friday, April 4, 2014

Jake is a salty dawg

 Here are some action shots from the last salt firing with Jake and crew



March Hints of the Week

March 2nd Hint of the Week: Corn Starch Blotter, found on http://dirtkickerpottery.com/ by Cindy Gilliland.
“The tip I read for making a corn starch blotter, instructed me to put the corn starch inside an old sock, but I'm sorry, old socks will not be used as a tool in my studio. I have to draw the line somewhere. Instead I cut a square of organic cotton scrap material, put about a half cup of corn starch in the middle, pulled up the corners and twisted a rubber band around it. It's cute and works awesome.



This metal stamp has my logo. I use it when making the little magnets that I include with purchase. (I don't plan to use corn starch with my bisque stamps, since I don't have a problem with them sticking.)

If you have issues with sticky stamps, try using corn starch, it's worth the extra step.”


March 9th Hint of the Week: Aging Clay By Beth Peterson in About.Com Pottery

Aging (verb) clay gives clay more strength and increases workability and elasticity. It is done by storing moist clay; extra water in the plastic clay is advisable, since the aging process will stiffen the clay. It is always easier to dry out an overly moist clay through wedging than it is to add water.

Several things occur during aging:
Full water penetration - It takes time for water to get mixed all the way through the tiny particles that make up the clay body. Even after mixing or pugging, a newly-moistened clay body will not have water saturated and present between all the particles.
Compression - Aging allows the clay platelets to compress, giving the clay more strength. (A thorough run through a de-airing pugmill also compresses the clay bodies and adds strength.)
Souring - Bacteria in the clay have a chance to break down all organic material. This thereby releases amino acids which act as flocculants, causing the particles to become attracted to one another. (The opposite of deflocculation.)

Also Known As: souring

Examples: When the clay smells like a swamp, it has probably aged enough. When mixed from dry ingredients, aging clay at least two to four weeks will greatly increase its workability.

March 16th Hint of the Week:
Write Down Your Glazing (taken partially from BigCeramicStore.com)Keep a notebook! No matter how much you think you will remember what clay you used, how thick you put on a glaze, what sequence you put multiple glazes on, how many coats, how many dips, or how long you dipped, or even what glaze you used to begin with, you will forget! And scraps of paper get lost. So use a permanent notebook, spiral notebook, 3 ring binder, composition book, etc. Write down everything you do, as you do it. I number my pieces so I can write down all the details of a particular piece. I can pick up a piece two years later and wonder how I did it. With a number I can go back to my glaze book and find out. But what I have learned over time is that I never write enough. After it is fired make notes too. I always look back and there are things I wonder, things I wish I had written down. But I am getting better. I am writing down more and more details while I am making and glazing a piece. I am trying not to let a piece leave my studio until I have recorded the results. And in many cases I am taking a photo of the piece with a digital camera. These things are already paying off.


March 31st Hint of the Week: Plates and Platters  Many people find firing goes much better when they notch or drill the plates' foot rings, which allows the trapped gases and heat to escape from under the plate. When they’ve used this technique the warping, cracking, and s-cracks were easily eliminated. The notches provided a way for air trapped under the foot to escape. Just make small, U-shaped or V-shaped notches, as the Japanese potter’s do, at the bottom of your foot ring. Instead of or in addition to these notches, you may want to drill holes in the foot ring. This will allow the gasses and heat to escape, and also allows for a wire to be used for hanging. This is especially nice for plates that are too large to fit into standard upper kitchen cabinets. Some people use a single hole, others two close together, others 3 or 4 spaced evenly around the platter.