Callie Beller Diesel

I don’t know about other lustres, but gold and white gold are made of those actual materials, and don’t tarnish.
Some raku glazes that contain a lot of copper can be prone to reoxidizing over time. Usually folks will coat pieces like that with spray varnish or similar. I think it could work for Palladium. 

I don’t know about other lustres, but gold and white gold are made of those actual materials, and don’t tarnish.
Some raku glazes that contain a lot of copper can be prone to reoxidizing over time. Usually folks will coat pieces like that with spray varnish or similar. I think it could work for Palladium. 

I don’t know about other lustres, but gold and white gold are made of those actual materials, and don’t tarnish.
Some raku glazes that contain a lot of copper can be prone to reoxidizing over time. Usually folks will coat pieces like that with spray varnish or similar. I think it could work for Palladium. 

Many commercial underglazes just don't hold up at cone 10. They start to flux out and that causes them to behave poorly when you put a glaze over them. If you're just looking for black or blue, you'd probably be better off making your own underglaze or slip. If you do want to use commercial underglazes, each color will need to be tested to see how it holds up and cone 10 and with your clear glaze.

I'd go with the 325 unless it's really expensive compared to the other. The finer it is the easier it will enter the melt.

I wouldn't get your hopes up on that. We don't get iron staining from our water, and the iron impurities in my kaolins are guaranteed to be significantly higher than whatever might be in my water. Public testing results are under 0.03mg/l, so only trace amounts. We also know for a certainty that iron gives a yellow discolouration in oxidation whiteware bodies. There's a solid chance it is caused by something in my water, but I don't think iron makes sense as we'd see this in all bone china worldwide.

Creeped your insta, my god your slip looks delicious, only way to describe it haha! That pink slip just looks amazing, luminous.

@AndreaK, lowfire and earthenware clay has been used for centuries around the world for domestic ware. How durable this particular  body is would have to be tested, I know some of the lowfire talc bodies were very weak. In North America  many potters have gravitated to midrange for various reasons, one of which is it's possible to have wares that don't leak or overheat in the microwave even if the glaze has crazing or pinholes and it's fine to leave the bottom of the pots unglazed. For lowfire (including earthenware for this conversation) in order for the ware to not weep / leak when used for mugs etc it is necessary to completely glaze the pot. (I do know someone who uses terra sig on the foot but that's another topic). A huge advantage of using lowfire / earthenware is the energy savings when glaze firing and the wear and tear on the kiln elements etc. 
Plainsman supplies really thorough info on all their claybodies. For Snow the link to it is here, click on each of the subjects and it will expand to give the details. For Snow the absorption figures are below. You can see that it has a huge absorption of 28% when fired anywhere from  cone 06 all the way to cone 2. You can also see that the absorption doesn't drop below 12% even when fired to cone 6. What this means is there is never going to be enough fluxing of the clay to vitrify it enough to be leak proof without a glaze. 
Functional ware made from this clay will need to be stilted when glaze fired. From the Snow page (linked above) it looks like Spectrum 700 glaze fits this body well with Snow being bisque fired to cone 04 and glaze fired to 05.

 

Hi and welcome!
It is possible to get durable ware at earthenware, midfire and high fire temperatures, but there are different considerations at each of those points. I won’t use the term food safe, because it’s a bit of a misnomer, and legally only covers whether or not the glaze has cadmium or lead in it. When we talk about glaze durability, we want to make sure that the clay is fired to a point where it would have less than 1% absorbion, the glaze doesn’t leach anything, isn’t crazed, resists both scratching and cutlery marking, and is easy to clean. 
With earthenware in particular, you have to be mindful of glaze fit, because earthenware clay remains porous when fired to maturity, and many will glaze the piece all over, and use kiln stilts instead of leaving a bare foot. You have to be extra mindful of your glaze chemistry, because the low temperatures tend to mean the fun, pretty glazes can sometimes be prone to scratching because they’re lower in silica and alumina.

Hi and welcome!
It is possible to get durable ware at earthenware, midfire and high fire temperatures, but there are different considerations at each of those points. I won’t use the term food safe, because it’s a bit of a misnomer, and legally only covers whether or not the glaze has cadmium or lead in it. When we talk about glaze durability, we want to make sure that the clay is fired to a point where it would have less than 1% absorbion, the glaze doesn’t leach anything, isn’t crazed, resists both scratching and cutlery marking, and is easy to clean. 
With earthenware in particular, you have to be mindful of glaze fit, because earthenware clay remains porous when fired to maturity, and many will glaze the piece all over, and use kiln stilts instead of leaving a bare foot. You have to be extra mindful of your glaze chemistry, because the low temperatures tend to mean the fun, pretty glazes can sometimes be prone to scratching because they’re lower in silica and alumina.

Ferric chloride isn’t necessary by any means. I haven’t done a whole lot of pit firing, but I did a couple back in college. You can get some lovely variations with terra sig on its own, especially if you’ve got a light and a dark colour to create contrast with.

Probably. 
Part of the fun of working with found materials is the variability. Sometimes close enough is all that’s needed.

Probably. 
Part of the fun of working with found materials is the variability. Sometimes close enough is all that’s needed.

Probably. 
Part of the fun of working with found materials is the variability. Sometimes close enough is all that’s needed.

I'm voting iron as well. I think that also accounts for the pinkish tint in low fire bisque pieces. If we were able to have a slab that thick of our clear glazes we would also see it to varying degrees. Window glass is also green for that reason. It look pretty darn clear when we look through it, but if you put some paint on it you'll see just how much color it really has. They make super clear glass, of course, but it's expensive. If I remember correctly they call it Water White glass. Standard  plate glass and such is quite green. I worked for a glass shop for a few years after grad school, and we would occasionally have to replace opaque colored glass panels on buildings that were no longer available from the original supplier, so we just had to paint the backsides. Getting an accurate color match was nearly impossible due to the tinting effect of the green. You couldn't just have the paint color matched to the old panel.

I use a talisman at work, and while it’s great for 10 gallon batches of glaze, it would be wildly impractical in my home studio. The cleanup of the brushes is a pain. 
I have a smaller sieve that sits in a 5 gallon pail at home, and I use a large round sash brush to push the glaze through. It works pretty fast and cleans up very easily. 

I use a talisman at work, and while it’s great for 10 gallon batches of glaze, it would be wildly impractical in my home studio. The cleanup of the brushes is a pain. 
I have a smaller sieve that sits in a 5 gallon pail at home, and I use a large round sash brush to push the glaze through. It works pretty fast and cleans up very easily. 

As much of the density or mass in a firing comes from the shelves themselves it's often helpful to put the taller pots on the bottom shelf, shorter pots and more shelves in the middle of the kiln and tall again on the top shelf. (assuming it has with just one thermocouple or is a manual kiln)

Density of the load has an effect on the way heat moves in the kiln. Kilns are heated by 3 different forms of heat transfer: Radiant, Conduction, and Convection.  Understanding these will help you to understand the need to pack the kiln consistently. Radiant heat is occurs first in the kiln as the elements radiate heat to heat up the air and the pottery. The pottery on the outer edges will heat up to radiate heat towards the center of the kiln. Please note that while Radiant heat is going on Convection is also occurring in the kiln as air heats up and begins to move to the top of the kiln forcing cooler air downward. Overly tight loads will inhibit the movement of air in the kiln causing areas that do not get air to not reach expected cones. However, as this is going on Conduction, where heat is moving through a solid, is taking place, Conduction is a slower process but it allows the pots to heat up from the outside to the inside, and the kiln from the inside to the outside. This good reason to have proper distance from the kiln to outside walls or other materials that could ignite.
Hope this helps to answer some of you concerns.
 
best,
Pres

Thanks so much for your repl
 
Thanks so much for your help. I think I'll adjust the firing schedule and make sure I pack it evenly! Really appreciate you taking your time to reply

I made a body of sculptures out of porcelain paper clay that were somewhat similar. I was using a translucent cone 6 porcelain and firing to cone 8. To prevent them from collapsing in the kiln I made a rudimentary saggar that I placed them into, then filled the void, as well as the piece, with silica sand. This went about half way up the side, I stabilized the "handles" at the top by rolling up some fiber blanket into a tight tube and running through each loop. For more complex shapes you can use kanthal wire to bind rolls to each other. Make the saggar (maybe armature is a better word?) out of cone 10 raku clay or fire clay so you can reuse them forever. 

Good luck, those pieces look great already.

If it’s one of those ones from Amazon, you may be out of luck entirely. They don’t have a good reputation for replacement parts or service. 
There is, however, and old trick you can use that may save you some searching. Place a sponge against the edge of the wheel head, and it’ll absorb most of the slip that flies off the wheel as you throw. 

Juried exhibitions or invitationals through galleries have never netted me any sales. They can be a nice ego rub, which has its own value, but that value isn’t monetary IME. 
Juried fairs or markets however, are a good thing. Juries can help put together a crowd of compatible artists and quality of work, which helps get it in front of people who are interested in such things. 

The grooves are probably not the issue, and also probably not doing much to prevent warping.
Waster slabs can be very thin, and can even be broken/in pieces, but should fully support the piece on it. It's just something that will shrink with the tile and keep the tile from catching on the kiln shelf. Put some kiln wash or alumina wax on the slab so it doesn't fuse to the clay. Waster slab does not need to be bisque fired.
No guarantee it won't crack in the second low-fire firing, but it's worth a shot if you don't need the durability of cone 5.
It's also possible that your tile is cracking from cooling too quickly, and therefore unevenly, through quartz inversion. You could try a controlled cooling from 1100F down to 850F.

2% cobalt oxide is a lot. Even 2% cobalt carbonate is a lot for most glazes. I would definitely test lower amounts of cobalt and see if you can get away with less.
Most chrome-tin pinks (reds) use about 0.2% chrome, which is very little. I just tested a light pink that only uses 1/10 of that! Vey difficult to weight out for testing!

Nope, trivalent chrome does not convert to hexavalent chrome in glazes.Re zinc chromate, according to Hansen "Chrome in zinc glazes tends to form the stable crystalline compound, zinc chromate (ZnCr2O4). which is brown." from this link. 
I plunked your glaze recipe into the glaze calc program I use but I'm not confident in the accuracy of it since specific types of potash feldspar, talc and china clay aren't mentioned in your recipe. Using generic analysis the formula is on the low side for silica though. I would do a lemon slice test on it and see if the colour changes., also keep a test piece in the dishwasher, if you use one, for a few months then compare that to an unwashed piece.What is really important is to have a stable base to prevent leaching. With colouring oxides, aka transition metals, less is better.