Hulk Posted August 28 Report Share Posted August 28 (edited) Buff stoneware appears to be weeping tiny droplets. Secondary: mixing clays, in my experience, no problem! ...until this, big bloat bonanza. Neither clay had exhibited any bloat propensity on their own. Much as it may feel and look like grog or sand, the tiny bits flick off with slight pressure from a fingernail (from bare clay), crush easily under a tool*, a touch from sandpaper obliterates them, and they look round, like drops. This buff stoneware can have a gritty feel after glaze fire. "Can" on account of, never on the liner glazed parts, not on the color glazed portions where the glaze is reasonably thick, and not on wares fired to just cone 5 but not over. I believe the liner glaze is "melty" enough to absorb whatever the droplets are. The droplets are perceptible where color/outside glaze is thin. Fired to just cone 5, the buff stoneware is shiny and smooth. I took these pics yesterday - the camera can see better than I can - last chance to get tiny droplets pics! I'd mixed the buff reclaim with a small portion of speckled buff reclaim. Ooops. I won't be spending any more time, energy or space on this clay combo. The buff, well, I hadn't intended to get any more, mainly on account of the gritty problem. The clays I like can take some heat work over cone 5. The speckled buff (different brand of clay) I really liked, planning to get more. Together, bloat city! *screwdriver tip, for example Edited August 28 by Hulk minor edit Quote Link to comment Share on other sites More sharing options...
Hulk Posted August 28 Author Report Share Posted August 28 The close ups above don't show the bloat much. Bloat bumps throughout... Bending cone 6, cone 5 touching Quote Link to comment Share on other sites More sharing options...
Rae Reich Posted August 29 Report Share Posted August 29 Sad lesson. Are the droplets glass, do you think? Hulk 1 Quote Link to comment Share on other sites More sharing options...
Hulk Posted August 30 Author Report Share Posted August 30 (edited) idk what the tiny white droplets* might be; hoped Glazenerd and/or some others might have some ideas. They are soft. The image with the red glaze, there's a tiny droplet on the end of a filament, interesting! The weeping out the bottom edge of the feet smooshed against the shelving; the bottom edges flattened against the kiln wash... I didn't mind the tiny droplet weeping enough to stop using the clay, however, mixed with the speckled buff, bloat-wow *The white globules, which appear round under magnification - on the foot there, which were also observed on the buff clay, not the speckled buff clay Edited August 30 by Hulk tiny white weeps, not the soeckles Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Min Posted August 30 Report Share Posted August 30 I don’t think it’s anything other than the manganese granules decomposing as it was overfired. Quote Link to comment Share on other sites More sharing options...
Roberta12 Posted August 30 Report Share Posted August 30 I had pimply bloat with Speckled B Mix (laguna) when I overfired. Some speckled b mix was mixed in with some reclaim that we were using for Empty Bowls. Pimply bloat again. It does fine at cone 5. Anything above, it seems to bloat. However, my bloats were not soft. Hmmmm Quote Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted September 5 Report Share Posted September 5 When Plainsman M340S was experiencing bloating, everyone thought it was the manganese speckle doing it, but it turned out to be one of the secondary clays involved in the formula. Maybe this is a similar problem? It looks like one of the ingredients has something that fluxes pretty readily at that cone 6 mark. Something with lots of sodium perhaps? Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Hulk Posted September 6 Author Report Share Posted September 6 Thanks Callie. The bloating, almost certainly having to do with mixing the two buff clays, both of which exhibited no bloating at all up to and beyond cone 6 on their own. Roberta, I'd meant to point out that the tiny white droplets are soft-ish - not as hard as sand granules; they crush easier. Min, not sure which it you refer to. The tiny white droplets (zoom in on the bare clay, the foot rim portion), that's unique in my (rather limited) experience. I've only seen them on the one buff clay, when fired over cone 5 or so. The bloating, I've seen that before, but not to this extent! I'd guess that there's somewhat out of sequence in the sintering/fusing when the clays are mixed together which produces the awesome bloating. Quote Link to comment Share on other sites More sharing options...
Min Posted September 6 Report Share Posted September 6 I thought you were referring to the manganese specks, thanks for editing your post. Without knowing what's in the clay it's hard to speculate what is causing the white spots/droplets. 2 hours ago, Hulk said: I'd guess that there's somewhat out of sequence in the sintering/fusing when the clays are mixed together which produces the awesome bloating. Yes, the whole is greater than the sum of the parts, just as with glazes. (eutectics) Hulk 1 Quote Link to comment Share on other sites More sharing options...
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