Babs

CMC GUM do the same?

Friend used to use inner tubes from various tyres, cut knotted , tied and so firth! Free

Rutile may do this, titanium dioxide opacifier, if dirty rutile may perhaps "leave behind" its impurities as temp goes up?

Hi, would you upload images and poss the glaze recipe then folk will be able to work out what's happening. Fickle nickel can cause honeys to blue in some conditions.

What cone are you firing to at present?

Do you use anything to help release the plaster from tin?

I have used it on unglazed bottom third of yunomi to get a toasty look, brushed on at bisqued stage. Be careful not to touch the washed area as the finish will be affected by this. I have only brushed, so can't comment on any othrr methods.

Well inside a functional pot would be better for hygienic reasons and to get a stable glaze where lips and food touch, it won't do anything for your problematic glaze. Could try dipping the pot in water prior to your first brush on, may alleviate the prob Dick mentioned re 1st coat applic. Or have a thinner pot of glaze for 1st coat so the surface gets fully coated. Interesting that the producer says it's finicky. Some filk drop temp after reaching goal temp. and soak to allow blemishes to heal over. Wouldn't help your elusive blue colour.

Have you used this glaze before successfully?

If firing it yourself, follow bisque ramp to 600°C then can adapt faster firing to top temp you require. If in studio ,i.e. you not in control, a bisque to Cone 04 would be fine imo

Can use a sealer end product and protect under wide verandahs...great lesson to learn re clay though, Callie. Folk here @glazenerd added laterite rubble to the clay mix!

As well, is it sitting on a suitable base? Distances from walls. I placed my"station" right next to the kiln. I fully explained the workings temps etc to classes, secondary. I erected a "fence" and I had a safety chain so noone could open the lid. Putting on whIn students left school , then there in the wee hours to check the turn off., kiln sitter. Unpack a day later, packand so on. I inherited 30 firings of previous teachers pots, adult classes as well as students, whew. Your kiln speci plates will say what cone it is capable of reaching. Have a good time.

Lots of mudbrick building and afobe in the 60's Maybe some of those books etc still around, unfired mostly. What's the climate in your area?

Another potter, Chris Campbell would be a great resource.

Is your kiln toploading? Do you use test cones?. Top shelves of top loaders can be cooler. Before altering everything, if have no cones, add a soak to top temperature, Try 10 mins to start with. Refire a failed pot in next glaze firing, on a lower shelf.

I have had a similar thing happen. I actually posted years ago. I live coastally so the rainwater added to the sodium. I took the glaze higher and added a soak . Prob solved . My glaze was a frit ,nephsy high C03 glaze, Didn't craze .

A cure used to be adding..Barium Carb to clay body if "proper" scumming. This one I'd be purting cones on shelves to get an idea of temp differences. Refiring higher would sort this I think. What is your glaze recipe? What is the temp you're firing to? Water supply?

Think the scumming pots have been fired at a bit lower temp. Can you wipe it iff and does it return?

Hmm busquing lower will increasd the porosity and so pit will suck moisture out of glaze more rapidly. Wondering if spraying pot with starch or sugar soln will seal it enough to allow glaze to be painted on more effectively

Notice re lead glaze firing, worth a checkbefore purchasing? Where would you install it? Ok for bisque if clean.

Ok, butyour clay will be very porous snd hinder the glaze spplicatin. Try dunking the piece in a bucket of water then glazing, can't harm It, let it dryif no good.

You could try bisquing to cone 04. Your clay will then be less porous and your glaze will brush better, water wont be sucked into the pot, along with Min's advice.

So ypu are using frit and nephsy and a little bentonite, and it is settling between brushes, i.e. you are constantly having to really mix your glaze and so the gum? From your original post. Am I way off to suggest super saturated saturated magnesium sulphate, Epsom salts , to help suspension? Or glycerine if "brushability" is the prob. What temp do you bisque to? What temp does your clay vitrify?

So ypu are using frit and nephsy and a little bentonite, and it is settling between brushes, i.e. you are constantly having to really mix your glaze and so the gum? From your original post. Am I way off to suggest super saturated solution of magnesium sulphate, Epsom salts , to help suspension? A few drops? Maybe photos would help. I'd be spritzing water on glaze between layers.

Cooking, ie powder form is mixed with very hot water, syrup thickness and left overnight. It is usually much thicker in the a.m. and I thin again.