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Hi and welcome to the forum. Just to clarify you are slurry mixing the slaked dry clay and including throwing water? If this is the case then adding some more plastic materials can fix this but I would test the reclaimed batch for absorption in case it also needs a top up of flux. For slurry mixing adding a 2-3 percent of bentonite (by dry weight) will get it back to being plastic. Easiest way to get the bentonite to mix with the clay slurry is to put the dry bentonite into a container of super hot tap water then whiz it up with a hand/stick blender for 10 minutes of so. It will turn into a very thick sludge, add enough water to make it like yogurt consistancy then add it to your clay slurry and use a drill with a jiffy mixer attachment (or similar) and whiz everything together. Tony Hansen from Digitalfire recommends dry mixing the bentonite with ball clay at a 1:1 ratio and using that. I haven't done this so can't comment on how well it works but basically doing the same thing. If you already have a batch of processed reclaim then try wedging in about 20% new clay, this might be enough to bring it back to a workable condition. BTW it is common to use nepheline syenite as a body flux.

Do you ever use roof flashing for casting of simple one piece molds? (just curious)

Hi Henry and welcome to the forum. Since you are in the countryside then zoning/regulations for a gas kiln might not be a problem but it's something I would look into, also if you have home insurance I would look into that aspect also. Do you have someone or somewhere that could walk you through firing with gas?

Hi and welcome to the forum. There is a thread linked below discussing iron speckles and granular manganese that should be of help. There are some images of both iron and manganese speckles. https://community.ceramicartsdaily.org/topic/26989-how-to-add-speckles-to-a-claybody/

If you calcine alumina hydrate to drive off the H2O you will be left with alumina oxide. (approx 35% LOI from it) Whether or not the mesh size is different I don't know. I found a pdf with mesh size of various aluminas here if you want to compare it to your alumina hydrate. If you don't calcine it there might be issues with both the glaze lay down and/or gassing off (plus the obvious difference of adjusting the recipe to allow for the LOI if you don't calcine it).

@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.

If there is a colour shift it's likely to be minimal if at all.

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)

I used to use a Talisman but switched over to using a cordless drill with a brush attachment and a regular plastic sieve that sits in the glaze bucket . WAY easier to clean up!!! Can clean the brush attachment in a small basin or pail of water or under a running tap. Takes seconds and no big sink needed. I have one sieve for clear and light coloured glazes and the other for the dark glazes. I sold my Talisman. To give credit where credit is due this idea is from @liambesaw

I have a Shelly bone china set from my Grandmother, it's at least 100 years old. I shone a (halogen) flashlight into one of the teacups, very translucent! However Shelly made their bone china I'm not seeing any green in it. (except for the on-glaze work)

That’s unfortunate. It will be a question of trial and error to find a commercial clear with low iron contamination to rid the glaze of the yellow tinge. At least from the info supplied in the link above you know which ones won’t be acceptable. Is mixing and testing your own glaze an option?

I would go back to square one and change just one variable at a time. Original recipe of 50 bone ash (one test with real and another with TCP) 25 Cornwall Stone (if @Jarman Porcelain doesn’t have any I think I have a small amount left that I can share) and 25 kaolin (grolleg). Mix that up dry then split into two and mix one batch with tap water (after flushing the tap for a few minutes) and the other batch with distilled water. At the same time I would run the same two tests with Veegum included. If these test show no green (or far less) then the field is narrowed down to something in the Cornwall sub being used.

Did you try the Spectrum glaze that was mentioned in your other post about the yellow tinged glaze? https://cdn.shopify.com/s/files/1/0039/8177/0841/files/105-LFW_Glaze_Rec.pdf?v=1674848426

Do you think there is a link between the Veegum and the bone ash or TCP? (Veegum being magnesium aluminum silicate) Interesting read here https://www.researchgate.net/figure/Concentrations-of-phosphorus-pentoxide-and-magnesia-in-Roman-emerald-green_fig1_277089354 possibly linking the two with a green colour.

Try sending @liambesawa pm asking about this. He hasn’t been on the forum for ages but when he was he was making lustres.

If it was iron I would hazard a guess we would see this more frequently. From my searches I haven’t been able to find any other cases of it. I find it very puzzling, wondering about colloids and phosphorus and the water used.

This thread is a continuation of this one. Some comments regarding the green tinge on page 2 of that thread.

I'll try and split this thread into a new one re Green Tint Bone China. Arggg! I lost the initial post, I'm sorry but @Jarman Porcelainwould you be so kind as to you repost your image/post from your first post here? another edit: the split did work, it just took a while for it to go through. Link to new thread below, thanks for everyones patience! https://community.ceramicartsdaily.org/topic/41608-why-does-my-bone-china-have-a-green-tint/#comment-256771

Are you bisque firing the underglaze on before glazing?

What are you thinking is causing the green? Chromium or copper? Have you tried one of the recipes that does produce the green tinge with distilled water to see if it still goes green?

Same make of splash pan as your wheel available here: https://www.amazon.com/dp/B0D1K8QWKD?ref_=ast_sto_dp Looks like it has just become available. Is this the correct size? I’m super impressed you could throw a 12 x 16” lidded pot on one of those small wheels.

I wonder if pyrophillite could be subbed for the kyanite. I have some pyrophillite, I could try it. Patch colour is going to be different than body colour though.

Trying to logic this through, I wonder if all or some of the dry clay in the magic water slip should be roasted first to remove some of the shrinkage of wet clay to dry. Blender some of the dry clay into a powder and roast that. (outside with a mask) I know there isn't much shrinkage from dry greenware through bisque temps but there is appreciable shrinkage from slip to dry. Bisque temp might be too hot causing sintering but roasting at 900-1000F could be something to try. Or a blend of unfired dry + roasted + paper pulp + magic water. I can see testing increasing amounts of sodium silicate amount also.

Hi and welcome to the forum and congrats on your kiln. The shut off timer is a backup safety device, the sitter with the small cone (or bar) is the primary device to shut off the kiln. If after firing your kiln a few times you know it takes 9 hours then the timer could be set to 10 hours to shut the kiln off in the event the sitter doesn't trip. It often does take several firings to get a kiln firing the way you want it to. I would suggest putting some witness cones on the shelves so you can see how it is actually firing. I don't know what cone you are firing to but for an example if your target is cone 6 then a cone pack with cones 5,6 and 7 would be used, this way you can see if your kiln is under or overfiring or just right. There is a little firing gauge you can get to calibrate your sitter. Also, I would put kiln wash on the 2 cone supports (but not on the sensing rod that rests on the cone).

Thank you for your kind words, very sweet.