Bill Kielb

I think You likely could recreate this effect with ordinary underglazes. Glass and ceramics just aren’t compatible IMO.

Is it your belief that the blue dots were created by adding bits of blue glass to the glaze? Frit to me are very specific set of manufactured compounds used by industry with very specific properties often used to substitute for mined materials because they are formulated and uniform as opposed to natural materials which change slightly or the formulation provides special opportunities often not easily available with mined materials. Some folks call these ceramic frit’s and they generally have properties such as a fired coefficient of expansion compatible with fired ceramics Glass however does not have these properties so combining glass and ceramics most often ends up in failure and something that is not durable for use. Have you contacted the person who made the mug above? It actually might be a lowfire claybody with a lowfire decorative glaze. There are several that have similar results. Amaco Crystaltex has similar blooming properties. Generally these glazes are only used for sculpture work though.

Maybe if you can match the value or get close it can be a nice project for solidworks and a 3 d printer to make an adapter.

@Brandon B @Dick White @Mark C. If I go to Mouser electronics and smart filter passive components by: potentiometer, slider,500k&1M I get a boatload of options that can be sized by travel, etc..... I think I would try the 500k and adapt the low and high speed voltage divider if they didn’t have enough range or install a fixed resistor as needed to limit the current if that was an issue. Seems like the original mounting was a bit aweful, but ..... they worked so I think I could epoxy anything in place with some bracing and make it work as long as relative travel and size were reasonably close. anyway, if it helps, looks like 500k or 1m available these days:

Not sure if this helps but at some point I got a Brent schematic from someone here which clearly shows .7 m double shafted pot for the pedal and a mysterious trim pot going into a voltage divider. Definitely not your pot but .7 M the value is interesting if they stuck with the diac control.

I would check your measurement of the existing. Especially if it’s in circuit, might have to disconnect two of the wires to make sure you are measuring the pot alone. I say this because low potentiometer ranges are not as common and when used they tend to (Not always) be a high current device. Having such a small change in resistance say zero to 200 ohms often leads to difficulty in precision. So double check first with nothing else connected and if it is truly prox 0-200 ohms neither the 10k nor the 1meg will likely do. Just need a 0-200. With that part number I would feel better if you would have said 26k ohms. Any chance your reading above is really in thousands?

Maybe this will help So these are infinite switches which have operated similarly for the last fifty years or so. So whether a stove burner, toaster, or kiln.........when the dial is marked as opposed to the back panel surface it maybe becomes more intuitive. Below: Skutt kiln, Toaster, stove top burner . (Can’t remember which is which though)

I think you have the answer If you are able to clean it then you should be able to measure it. Pots are rated end to end. To check linear or audio taper set the slide to midpoint and measure wiper to any side. If approximately half, then linear taper. If significantly different than half then audio taper. Very likely linear though. Post and tag the value here for folks in the future.

Cone 04 -06 for bisque to sinter midfire clay so you can glaze and handle it. Slow bisque firing about 200 deg. f per hour or let’s say 8-12 hours to completely burnout organics. And slowly dry things out in the beginning of the firing so from room temp to 200 f go slow for an hour or two. In other words what you read above is likely the only way to get this done. I wish they would have named it semi automatic kiln actually. That’s my experience.

Zinc can affect some colors so folks generally want zinc free clear so as not to affect underglaze colors. A fluid glaze is one that melts and flows a bit. It can be achieved in a number of ways such as making the glaze melt a bit earlier with more flux and even if the glaze by composition has relatively low amounts of silica and alumina. There is no magic predictor of when a glaze melts, it melts by composition so all glazes are really tested at or around their cone range for a good melt as well as how much they move when fired to a particular cone. It’s just a gravity and fired fluidity thing so there is no magic answer to give you. Experience is the best predictor and maybe some folks will offer up a favorite recipe. When I want something to move more I will increase the boron slightly to get it to begin melting earlier, say cone 4 instead of cone 5 for example. But testing always is the final decider.

@Mark C. I think they wanted to make every firing a learning experience or teachable moment as we say.

@M5Pots Thicken the underglaze strategically along with a fluid clear gets some control in the bleeding areas. Have also achieved interesting similar looks by using underglaze over bisque, and misting with a very fine mist to get movement pre glaze application. A judicial spritz or two from a well controlled air gun also helps move things in custom ways while spraying past stencils also allows for some custom feathering especially with an airbrush.

cone 5/6/10 You should be able to re-bisque them. Bisque temperatures generally only sinter clay which is not really melting it.

If it’s bonded nitride it should scrape off and if additional cleanup is needed very light stoning or a small piece of similar shelf is what I have seen others use with great success.

Yes, the big dial that says overglaze, ceramic, high fire according to the manual acts as a low, medium, high dial. Automatic I believe gets you two hours of an alternating on/off interval firing to slow down your initial firing temperature rise. This was an early attempt to semi automate drying things out slowly. Leave this knob (the big knob) on the lowest setting initially and turn it up gradually so maybe 3 hours on the lowest setting (overglaze) then two hours on medium (ceramic) , then the remaining on high. You only have a single knob so all the elements that can be controlled are controlled by that knob. It’s a little backwards or counter intuitive from what you might expect. If three hours on low is still too fast, then four hours on low etc......

Go slower! Bisque fires or any form of them (biscuit?) are done slowwwwwwww to burn out organics. Figure out how to go slower by turning the power down. Going slower will also be more even throughout the kiln. Bisque fires - get yourself to 9-10 hours. Glaze fires, about 7-8 hours each to start. Glaze fire your clay to it’s maturity and use a matching cone glaze.

I think bang for your buck, inside top and bottom only.

Looks really good. This might be a candidate for interior refractory coating, extra rigid insulation on the bottom and some nice lightweight shelves to maximize the number of firings ya get on a set of elements.

Your manual https://216.198.210.227/files/manuals/LX_914_Duncan_Kiln_Owners_Manual.pdf this link should work. You may have to accept going to a non secure site. This is the old non https compliant site. basically for bisque, time is needed to burn out organics which means a slow firing (200 degrees per hour) of about 9-12 hours. On automatic set to low and start. First two hours is auto then reverts to infinite switch knob setting. You may need to manually raise this as time goes on to finish in 9-12 hours. Page 13 lowest setting is overglaze then ceramic then high fire. Think of it as Low, Medium, High actually and it should make more sense.

Ought to save a decent bit of energy as well or at least add some pep back into your firing. Old shelves can end up to be near half the mass of the load. Fired shelves look just the same before and after so a significant waste of energy and not even an aesthetic result.

I reached the end of the Internet one day, it scared me! Back paging was a pain also.

Not to worry, I have seen several theories on this but nothing definitive and suspect it was a combination of things oddly culminating in the number 6! Certainly not as definitive as cone numbers which seem to have a reasonable evolution. Cone 6 definitely a game changer though.

Cool, Best I have heard I am running with it! What timeframe were these done if you know?

Looks fine, maybe “ within” is a bit narrow and “contributing to” or something to that effect is broader and includes processes and innovation outside art and crafts ceramics that end up being of significance. Don’t know if “traditional” is helpful in this context maybe enhancing traditional ...... something to that effect.

I never could find out why 6, not five, or four or seven? And energy, only anecdotally. Cones are a great one but credit Hermann Seger. I like all those examples though, hidden game changers right in plain sight.