[Pazu]

Hello, I am an artist from NH. I have a tech day job. Skill level - early learning curve. Next firing will be the 4th with my own kiln. Considering my experience level, I have joined this board hoping to learn and try some better approaches.

At some point I arbitrarily decided that I would make chess sets, and I am enjoying doing so. Please see picture attached. So many mind-blowing experiences of personal discovery in the process.

I'm at the point of re-evaluating materials and in reading here and elsewhere, I learned of "micaceous clay" and its' properties of handling a flame and also being low-fire. But, is it that durable in actuality? For chess sets I need chip & breakage resistance. It's 2 issues, the surface chipping from an impact, and structural breaks. I haven't run into these problems, but the choice of Amaco 25 clay at ^06, probably can be improved upon. My kiln is ^5 but perhaps I could soak to a higher cone. Stoneware would be stronger, uses more energy.

I'm concerned with uniformity and execution of the pieces and will focus more on that in the next set. I will use the wheel and other techniques to make them look more turned than modeled then, but first comes the material that I will use. I have some Amaco 65 porcelain clay which is ^5 and I was going to try that until I began reading about micaceous clay. Also, there's the paper clay.

I would appreciate any thought on clays best suited to this sort of purpose.

Thanks - John

 set1.jpg (296.93K)
Number of downloads: 161

[neilestrick]

I would go with the cone 5 porcelain. It will be hard and durable. The construction and design of the forms are just as important when it comes to chip resistance, though. Sharp or thin edges will cheap easily. So you may want to redesign your forms to make the disc shaped collars thicker or narrower. Also make sure the bottom edges of the pieces are slightly rounded, not square. Don't feel like your pieces have to match the traditional chess forms.

[Pazu]

neilestrick, on 15 December 2012 - 12:39 PM, said:

I would go with the cone 5 porcelain. It will be hard and durable. The construction and design of the forms are just as important when it comes to chip resistance, though. Sharp or thin edges will cheap easily. So you may want to redesign your forms to make the disc shaped collars thicker or narrower. Also make sure the bottom edges of the pieces are slightly rounded, not square. Don't feel like your pieces have to match the traditional chess forms.

Thanks, got your point about designing to avoid chips, & about going in different directions with the sets. I'm actually trying to remain within the ballpark of the traditional Staunton forms for the moment. If the set had a theme, it would be "chess." The collars on the personified pieces, the rook in form of battlement as compared to chariot. I could go on forever about it; the Staunton pieces evoke legitimacy, universally understood and functionally clear to the modern game. I'm jumping that train to some degree, I'm comfortable there as a chess player myself. So, fun to approach that common symbology while going elsewhere as well such as ovoid finial on the pawn as compared to ball, the modeled look being almost brutal like the game, the queen is designed as rather busty and the ovoid theme carries through the royal pieces. Heavy, glossy, an elegance of sorts with their felted bases. I'm still working on the royal pieces. The next set though will be finer with a more uniform, turned look. I'll have to take the glaze in a different, unknown direction as well, @ ^5. Should be interesting. Thanks again for your thoughts Neilestrick, Onward! - John

[Lucille Oka]

Just about any clay is suited for these pieces because the nature of the pieces are short, stocky and heavy bottomed.
I agree with Neil about your design, avoid thin, narrow necks, pointed, long and unbalanced horse heads. You can also finish the bottoms smoothly so they will glide. A well made cloth surfaced board, in dark velvet or felt can help avoid breakages and make the set appear a bit more elegant.

Amaco's 'White Art Clay No. 25, Talc Free' has a cone firing range of cone 05 to cone 3 (1911°F-2138°F).
The bisque ware temperature is cone 04, 1971°F. The recommended glazes however are low fire at cone 05 (1911°F)

Porcelain #65 is very sturdy. It is a good idea as Amaco suggests to fire the bisque at the high end of cone 04 (1971°F) for glaze application. At 2205°F, you will get a very good product that is compact and dense and 'rings' on thin pieces when thumped. The Amaco glaze choices are also quite remarkable at cone 5-6.

[Pazu]

[/quote]

Lucille Oka, on 16 December 2012 - 04:24 AM, said:

Just about any clay is suited for these pieces because the nature of the pieces are short, stocky and heavy bottomed.
I agree with Neil about your design, avoid thin, narrow necks, pointed, long and unbalanced horse heads. You can also finish the bottoms smoothly so they will glide. A well made cloth surfaced board, in dark velvet or felt can help avoid breakages and make the set appear a bit more elegant.

Amaco's 'White Art Clay No. 25, Talc Free' has a cone firing range of cone 05 to cone 3 (1911°F-2138°F).
The bisque ware temperature is cone 04, 1971°F. The recommended glazes however are low fire at cone 05 (1911°F)

Porcelain #65 is very sturdy. It is a good idea as Amaco suggests to fire the bisque at the high end of cone 04 (1971°F) for glaze application. At 2205°F, you will get a very good product that is compact and dense and 'rings' on thin pieces when thumped. The Amaco glaze choices are also quite remarkable at cone 5-6.

Hello Lucille, thank you for your ideas. I added a photo below to better illustrate the bases & the felting and also what I'm concerned about regarding chip resistance. When removing a piece from the board in a game one often has the victorious piece in the same hand; that clinking together of pieces is one point at which chipping could occur. If someone throws a piece, or drops it on the floor, can't do much about that!

Because of the wide dimension of the bases and the finials, if the pieces are on their side on a surface, the collars don't hit first. The edge of the finial, collar and base form a line and hit more or less together which should help to distribute shock and protect the collars a bit. I do like the idea of more rounded collars that do not protrude as much, so I'm headed in that direction for the next set.

In this case it is the pieces themselves that get the felting, to slide on a tile, polished wooden or rollable vinyl board. I've already bought black felt with one side adhesive. I see the point you are making, a cloth board would reduce the likelihood of chipping. You can see the felt on the bottom of the test piece in my hand, in the photo. That test piece is very rough, barely round. The purpose of that was to test Amaco glaze pencils and how they would appear on a fired piece. I learned that the hues are subdued rather than vibrant.

So it's on to finishing the royal pieces. The king & queen are more elongated but I'll try avoiding going thinner than the pawns. The knight, well that is the most challenging piece from a design standpoint. I've looked at *lots* of horse pics lately, fighting horses, armored horses. The traditional Staunton horse looks like a horse that doesn't think that it is very threatening-looking. It is just sort of there. The power and threat of the knight should come out more in the piece, like a horse rearing with its' head all thrashing about. Most horses spend 99% of their lives thinking "is it time to run yet?" Which from a human standpoint is a fairly paranoid and cowardly perspective. Hoping to find a design that says, "not time to run - time to FIGHT!" Meaning no disrespect to the animals, just want to represent the more fierce side of their personality. That is a tall order considering my skill level so I'll probably have to get their through abstraction. Not that an abstracted war horse is any easier, just faster to form and I can't get bogged down in pieces that take days to identically model.

Firing the Amaco 25 at not cone 05 but cone 3, would this directly translate to stronger pieces, just through that glassification process at the higher temp? The current ^5 glaze would slump off on to the shelf right so it's too late for this run. Forgive my ignorance but not having taken classes I have *lots* of blind spots to fill in. I did not bisque fire these pieces to Cone 04, only to Cone 05, same as the glaze. Do I need to throw these in again & crank them to 04 because I didn't get them to vitrification? Seemed pretty hot to me!

The commercial ^05 glazes used in this set, were Mayco Crystallex in Cosmic Black and Northern Lights, with Amaco LG-10 over that, but now it's on to cone 5 land for the next set. I have a set of Amaco Potter's Choice glazes that are cone 5. I like the idea of ringing pieces! These pieces chirp but do not ring.


Thanks again Lucille for lending a hand with your thoughts,

John


 bases.jpg (247.88K)
Number of downloads: 54

[Lucille Oka]

Hold it! Clay and glaze must be compatible. Amaco's #25 has a firing range from cone 05 to cone 3; as far as I know Amaco does not make cone 3 glazes. But there are other companies that may make them or you can formulate them or mix them from a recipe. So, if you decide to use Amaco’s #25 low fire clay, use a compatible glaze that at least matures up to cone 3. That also means test, test and test.

#65 Porcelain is considered a midrange clay body and has no ‘range of firing’ it is a cone 5 clay. The glazes you can use mature at cone 5 or less but be sure to bisque fire to cone 04-1971°F. It does make alot of difference for glaze application. Be sure to test.

If using another company’s glazes, test, test and test to see if they are compatible with the clay.


Please if this is not clear, please say so and maybe I can or someone else can explain it better.

[Pazu]

Lucille Oka, on 16 December 2012 - 08:25 PM, said:

Hold it! Clay and glaze must be compatible. Amaco's #25 has a firing range from cone 05 to cone 3; as far as I know Amaco does not make cone 3 glazes. But there are other companies that may make them or you can formulate them or mix them from a recipe. So, if you decide to use Amaco’s #25 low fire clay, use a compatible glaze that at least matures up to cone 3. That also means test, test and test.

#65 Porcelain is considered a midrange clay body and has no ‘range of firing’ it is a cone 5 clay. The glazes you can use mature at cone 5 or less but be sure to bisque fire to cone 04-1971°F. It does make alot of difference for glaze application. Be sure to test.

If using another company’s glazes, test, test and test to see if they are compatible with the clay.


Please if this is not clear, please say so and maybe I can or someone else can explain it better.

Your advise is clear Lucille, thanks.

I'm not quite clear though as to whether I am good to go with the pieces that I have already done, or whether I ought to throw them back in the kiln to be certain I've got them to ^04. They have only been fired to ^05 at this point. I don' t think that the glaze will be radically affected by taking it to ^04, and if it will make the pieces a lot stronger or more chip resistant, it would be worth it, though they seem strong enough now.

These pieces were single-fire method, some will cringe at this no doubt but please understand, I haven't had enough experience to know better, quite yet. If I can get away with turning these out in a single-fire process I'm going for it for the simple reason that they will cost me $20 and a firing day less to do it. I need to install a new outlet in my home to accommodate my kiln so for the time being I am running it off of my generator, and it uses between 4 and 5 gallons of gasoline to complete a slow bisque fire to ^05. So that could be $40 for the two firings and it's a small kiln. I can afford it but cost-effectiveness is important as well.

The Amaco 65 porcelain clay and the Amaco Potters Choice glazes that I have, are compatible, both cone 5, so they should work out? So for best practice I would slow bisque the Amaco 65 to ^04, then glaze them and do a fast glaze up to ^5 I believe.

[Lucille Oka]

Yes, they are compatible very much so and they are beautiful together. But do a test of the colors you are planning to use to see how they run. Make some test tiles that stand up like a ‘tent’ then you can write the glaze name and number on the insides. Use a dark underglaze pencil (they work better dipped in water) and draw a visible line across an area on the tile and apply your three heavy coats of glaze above that line. Flat tiles will not reveal the fluidity of the float glazes, but they will show the colors and textures of the PC 'Typical Transparent or Opaque Glazes'.
I also made small Sake test cups just like Amaco's test vessels however I made them with small troughs and a sprig to catch and watch the flows. I concentrated the 3 heavy coats on the inside of the vessels until I understood the nature of the glazes. I used two or so coats on the outside but feathered up from the foot.
I bisque fired to Cone 04-1971°F and glaze fired to Cone 5-2205°F. Be sure to read the labels on the glaze jars some of the glazes say fire 'at Cone 5-6'.

I did fast fire the glaze load because the bisque fire was so high and was only 234 degrees from the mature glaze temperature.

If you do what Amaco suggests you should have success. They even provide a picture to show how to load up your fan brush. Don't be timid about the application. I had no excess running but still be sure to kiln wash your shelves just in case.

[Lucille Oka]

Sorry, I overlooked your concerns about the ware that you have already fired. I would just leave it as it is and take it as a test. You can make your next batch sturdier and fire to clay and glaze maturity. But first test the clay and test the glazes.

[weeble]

The problem I see is your clay has a firing range of cone 05 to 3, and you are firing to the lower end of this range and having problems with chipping, correct? At the lower end, the clay is probably not vitrified and that means its not as strong as it can be. I dont know the specific products you are talking about but some of the lower fire glazes will fire succussfully at higher temps, so a test would be in order.

[Pazu]

Weeble, I haven't chipped anything yet. I clinked some of the pieces together a bit, and they held up fine. Looking to work with the toughest clay possible so that the pieces have the highest probability of withstanding the test of time; as game pieces, they must hold up to use and storage. I want to be using the strongest clay/glaze combination out there, up to ^5. I'll single fire the remaining pieces @ ^04, 1 cone hotter than the others, and with hope not much glaze color appearance or deviation in patterning will occur as these are two sides, sets of 16 each. They should look like they belong together. Perhaps the hotter cone will also lessen the crazing that is evident on several of the pieces. No big deal, it was probably due to a novice excess of glaze. Now I know I can go with less. Since some pieces did not craze, I know that the clay/glaze combination can work. I am assuming that a crazed piece is more likely to chip or break, as compared to one with a contiguous layer of glaze. That's the only reason the crazing bothers me. Thanks for your thoughts, I'll turn up the heat a bit and test.

[Frederik-W]

If people want unbreakable chess pieces, they can buy ones made from metal.
Don't forget the aesthetics of the object. Why would people buy them ? because they are beautiful or because they are rock-hard? People who buy chess pieces made from glass or ceramics know what they buy.
By nature ceramic objects are breakable if you mistreat them, no need to cripple your style to make them harder. As you say, they hold up fine.

In all probability the chess pieces will get lost long before they break.
Make a few extra pawns.

[Pazu]

Frederik-W, on 21 December 2012 - 11:33 PM, said:

If people want unbreakable chess pieces, they can buy ones made from metal.
Don't forget the aesthetics of the object. Why would people buy them ? because they are beautiful or because they are rock-hard? People who buy chess pieces made from glass or ceramics know what they buy.
By nature ceramic objects are breakable if you mistreat them, no need to cripple your style to make them harder. As you say, they hold up fine.

In all probability the chess pieces will get lost long before they break.
Make a few extra pawns.

All good points Frederik, thanks!