Bill Kielb

This may help or this may confuse you. We use the UMF to understand our glazes chemically. So in your example above the boron went from 0.58 to 0.67 a significant change even though the same weight of each compound was used. The relationship under UMF is relative and is a comparison of atoms. Here is a quick how to calculate UMF that may shed some light. https://www.youtube.com/watch?v=HyLjAg1_8_4

If you look at orifice tables they are generally in inches so most burners are designed for inches of wc because natural gas has a bunch of energy and even with a really small pressure one can achieve lots of btu with a tiny orifice. At 1/8” diameter I can get 100,000 btu with only 9” of. Pressure. (About 1/3 of a psi) That same orifice at 2 PSI will be 144,000 btu. Propane tanks are relatively high pressure so they can hold a reasonable amount of liquid propane in a small bottle and operate in low temperatures.. My advice: follow the design tables that we have used for the last hundred years. Will it improve adjustability, definitely, just use a metering hand valve to control your burner like most kilns. When you adjust the hand valve you are essentially dropping the pressure across it from zero to 1” to 2” etc…. That’s WAY harder to do with 30 psi on one side of it than with 11”. BTW you need a valve so you can adjust the kiln output as needed. In the beginning, small flame gradual warming, at the end more heating. This is just firing, a kiln doesn’t cycle on and off maintaining a temperature as if it were an oven. People hand fire it according to their schedule. It never starts out full on and just roars through the firing. Set your regulator at 11” and adjust downstream with the hand valve. This way as tank temperature and pressure changes you will always have a steady 11” to your kiln and your last hand setting will remain consistent. Are burners in general sized for inches of water, YES - Stoves, heaters, grills, dryers, fire places, kilns, Venturi burners, basically gas appliances. Can you pipe high pressure propane - YES. Is it more dangerous than low pressure if there is a leak - YES, without a doubt. If you run low pressure do you need a larger diameter hose? - yep, follow the tables. Can you cram PSI through burners sized for inches? Yep, the head loss (friction loss) goes up enough so the burner puts out more but the head loss becomes really high. Are orifices designed to operate in inches that way for a reason Yep, always have been. Do most propane appliances have a regulator built into them? YEP PSI to inches of water column. Are inches of pressure misunderstood by many - in my experience, YES Call Ward for sure, he is used to this - once inches of water column is understood, generally the mystery goes away. here is a very generic video you might find interesting https://www.youtube.com/watch?v=T-QhRrQA21g Orifice table (inches of water Column) Finally, for CSST it looks like 3/8” inside diameter at 10 feet is fine for 100000 btu but check with your hose provider based on 11” of water column what diameter hose

I still think pictures of the failures would help folks formulate a more informed opinion or basis for other questions. Post some if you have any.

It’s just molar math. A mole of something contains 6.022 X 10 (raised to the 23rd power) of something. Atoms, molecules, particles. Since the components such as silica, Alumina etc…. Contain different grams per mole relating everything to moles is the great chemistry unifier to grams. Now the mixture of each substance can be compared accurately. Use the formula amounts, they are there to make everything relatable to grams. The formula weight for 3195 = 339.82 and the formula weight for 3134 = 195.57. The formula amount ends up to be the actual how much of a component is present even though the two formulas vary significantly by weight and have different portions by percentage. Your logic is good, but I will say once your glaze is melted you are depending on gravity to make the glaze move. Melting it a bit earlier can give gravity more time to pull this glaze down or for it to break and flow across ridges. But glazes are stiff for other reasons. A popular one being how much Silica and alumina are present. Thick applications help because they help gravity pull everything downward. If the fired viscosity is stiff though, it wont be enough to move it and melting earlier only provides more time for it to perhaps move slowly. Reducing the silica and alumina Will definitely affect the viscosity but also can lead to glazes with less durability. If your glaze is melting now and you melt it one or two cones earlier and it still will not move, it’s likely too stiff and additional boron will not necessarily make it runny. Lots of testing using lots of care when making runny glazes is always good advice, else ruined kiln shelves, wares, basically heartache ….. Look at Glazy runny glazes and observe the commonality. Cone 6- 10 and then: Low silica, low alumina, both, high R2O values, None of those chemistry traits are great for durability though.

They look different to me, 3195 on top, 3134 underneath I believe 3195 has more silica, more alumina (10X), almost double the boron, very similar sodium and calcium. The percentage boron are similar but that percentage is based on how much of the other stuff is in the recipe. Total boron is not quite double for the 3195. 3195 is a cone 06 glaze basically, add some clay to suspend. I am not clear what you are doing actually combining Frits. In the recipes above boron has gone up from 0.58 to 0.67. Boron at 0.45 basically gets you cone 04 melt.

Most likely they have absorbed water / liquid. Unfortunately I don’t have an easy way to remove and test other than firing in an electric kiln with a hold at let’s say 190 for a few hours then maybe raise them to 250 degrees for several hours. If you had an evacuation pump this would be easier and not require the heating. To @Rockhopper point above, I assume they overheat in several different microwaves, easy to try……. Sorry, Maybe someone here will have a better idea.

Maybe a bit of Right tool, right time actually Maybe just use some lugs for this, GG probably not the best choice.

I believe A stamp with the letters sticking out or raised to create an impression is easier to use. To impress a circle around it you could create a stamp that includes a raised circle. All would be impressed in the clay. In the picture below an encircled stamp on the right with its own border and on the left - no border.

Just my observation, embossed stamps / chops are often easier to impress in clay. Sharp edges on letters and clearly cut lines can help. Often the wider the letter or image, the harder it is to impress in clay. My experience embossed ends up easier to use than incised.

Post a picture or two of the cracked handle and mug.

It could be different, the only way to know is test fire and do an absorption test. I still don’t understand why it is making it through the glaze though. Maybe some really fine crazing but I would expect to see that in the stains. Do they use witness cones to confirm? My only thought is the glaze and clay likely are not mature. Maybe someone here will have a better thought.

just an FYI - I am not aware of any end of fire holds in their cone fire schedules. Usually adding a 15 minute hold drives it to the next cone.

I can’t help wondering …. I assume it’s glazed and can’t help wondering if this isn’t just a coffee stain that comes off with a little scrubbing similar to my glass coffee pot which gets a nice cleaning with a mr clean eraser about once a week to remove the light staining. Having said that cone ten clay fired to less than cone ten usually ends up less vitrified and more absorbent. Looking at the graph for this clay though it’s roughly 1/2% from cone 8-10 so not bad. For the clay you can always check by doing some absorption tests. My question would be more of why is the glaze staining? Of course the glass in my coffee pot stains and it is pretty durable glass. If anything I would make sure the glaze is a reasonably durable composition which can be tested as well. Folks often make durable liner glazes just to be sure their food wares are as safe as practical. If the stain scrubs off, then is the glaze durable and are we scrubbing off some glaze or is it as durable as my glass coffee pot? if the stain is embedded under the glaze, the glaze is likely not very durable.

Cool, seems like you ruled out all the possibilities and actually glad it’s type K. Sorry, just recently had a gal use a type R for an S or Vice versa - very confusing. You likely gained a bit of power by pulling all the old switches out and certainly gained some consistency as I recall it was on a downhill slide of making less temp each firing.. Now I think it’s time to run the cone fire program just to see what it will do with its current available power and have the controller compensate as necessary. You can still run your drop and hold at the end I believe. Maybe gets rid of the babysitting issue and lands on a cone. And yes, any type K it will perform basically like any other type k sleeved or non oo you determine it’s just a bit under powered and you want to squeeze more power out of it then anywhere there is a bad connection or voltage drop will be wasted power. I usually use an infrared thermometer to quickly see if one terminal of like loaded terminals is running way warmer. If it’s 20-50 degrees warmer then worth checking the connection. Cord ends, receptacles and even one side of a breaker will heat up if the connection has loosened I have found all the aforementioned at one time or another actually. . This would be tweaking and I would not expect a large gain unless you find something pretty hot. Still a fairly quick way to keep an eye on things.

I think I would use both and that’s me just being extra cautious. To me It looks heavy and the edges will bear firmly on what they are placed upon. It’s a nice piece, wouldn’t want it to get caught on anything.

my thought- This would be a candidate for a cookie or waster underneath for me and alumina at the intersection of all junctions so nothing binds as it shrinks, above and below the cookie. Setting this on paper towels or newspaper as it dries definitely let’s it shrink nicely as it dries as well. Fire on a nice flat straight shelf.

Hmm, interesting, Type R or Type S? And is the controller programmed to match? If not it definitely causes issues because the profile between the two is enough difference and a proven way to over fire things. Many manuals make special note, especially type K to type R. Generally a thermocouple won’t make your kiln slow down in its firing and slowing down means you are running out of power to keep up with the ramp. Since you have a type K to test with though, I would definitely change it, make sure your control is set for type K and also just run a slow glaze cone fire program to see if it will follow those speeds reasonably. Type K most often just break before they drift too much. I am not a fan of custom programs without sound reason and even less a fan of holds because often the kiln can’t really keep up with the custom program and it’s tough for folks to know the actual rates which eventually often leads to what appears to be random results At least in cone fire mode the controller will compensate for the speed. First I would verify type, programming and even room temperature. The type should be stamped on the thermocouple, make sure the internal programming matches. Type R & S can look the same and often have no specific color for leads in the US. They do have slightly different profiles though so if found programmed in error would require another test run with the appropriate type programmed into the controller. I would also run a cone fire program (slow) the expected speeds are reasonable. A thermocouple is just two dissimilar metals joined together and they become a battery that supplies a minute voltage. They can drift over time but eventually break and just quit producing a voltage. Type R & S excerpted below, note the minute difference in output, which insidiously get larger as temperature rises. The difference in output is not necessarily linear through its range which can make temperature and speeds appear odd when mis-programmed and generally a sure fire way to mess with your controllers (and your) perception of temperature. Last observation, since your thermocouple is in a metal sheathe, make sure the metal cannot contact adjacent kiln metal especially as the kiln heats and expands. This can generate electrical noise or in the case of a grounded sheath can cause all sorts of random issues as well. A very final thought - as potters we generally don’t think in terms of peak temperature but rather rates and time at temperature. Since our reactions don’t begin until there is enough energy for the fluxed reaction to transpire the heating work beforehand often has limited value with respect to maturity. Rate in the last 200 - 250 f degrees is super important to maturity and holds at peak drive the heatwork towards the next cone because we are in the midst of the fluxed reaction. Cones are made of glaze, they visually show the heatwork attained in the zone of maturity.

Nice work, easy to give up. Way to stick with it! Hopefully you are all set.

Yep, looks good.

That will work, in essence take both wires from each element group and extend them out to the electrositter. Two wires from each element group, two output posts on the sitter. Meaning you will be bringing 4 wires to the electrositter. Make sure remaining splices are tight and also make sure the wire thickness is the same. Very important as the connection to cycle the control relay could be lighter gauge. I doubt it, but it could be which would be a reason not to use it.

I would submit your kiln may draw 48 amps @ 240 v nominal so 11520 watts max. You will need a 60 amp breaker and wiring to satisfy the limitation of loading a breaker 80% maximum. From there you can add your other loads and characterize them. The AC being the toughest to start on the generator. A 3 ton Ac unit might run on approximately 15 amps but it takes 5 times the current to start it or 75 amps. So a simple 3000 w load grows to an Effective 9000 watt łoad at startup with the AC unit. A general rule 5 times the amps, 3 times the watts - at startup. My point, inductive loads are killers, hard on everything including the grid because of a power factor less than one. Resistive loads are fine, but their true wattage must be accounted for. The cure for the AC used to be a hard start kit installed on the AC unit (Big capacitor) because at 5:1 on startup you quickly run out of capacity with most generators. Tell your generator guy what wattage your kiln is, he will size for it like most other things - to cover the wattage.

No, I am not confident. As an example there is nothing connected to terminal 7 and you have it being installed on the electrositter. Maybe best way take a context photo showing your elements and the wires leading to them. Step back a couple feet and get them all in the picture. Then we can annotate that so there is no confusion. Right now it’s too hard by description only. The terminals marked zero (0) and one (1) only turn the relay on.

Yes, if it’s whole house then the breaker will need to be sized for 125% of the kiln rating but that is to protect the breaker and ensure the breaker is never loaded more than 80% of its rating. Again, all about the breaker. Large inductive loads (like.an AC compressor) are very hard starting on a whole house generator. Kilns not so much except it will be lots of watts for many hours. What is the rating of the kiln (watts & amps) and what is the generator rated (watts or kva) The generator will need to be sized for the watts, not necessarily 125% that’s only a requirement for the breaker. When kilns start and stop, there is little inrush. Quite opposite to that of a large motor starting so it is fairly gentle comparatively. Your generator will need to be rated to supply all the watts for the home though and if you have an older ac unit, etc…. Be sufficiently oversized to start the AC unit and all the wattage being consumed by the home. A 10,000 watt kiln is very similar to an Electric stove. Easy to start, just lots of watts.

Hmm, I need a better way to do this. This should be your relay including the numbers. The wire on terminal 6, connects to the wire on terminal 8. The wire on terminal 2 connects to the wire on terminal 4. You should be able to take a picture and include the numbers which would allow us to confirm. You are only jumping out this relay so the elements are powered all the time your controller sends power to the kiln. The relay in the controller will cycle everything on and off as it needs to. I am assuming your kiln is wired into the controller. The middle elements are powered by the top infinite switch. If you have jumped H2 to L2 and H1 to L1 on that switche then you have jumped out that switch as well. Whenever power is applied to the kiln all elements will come on full. Again pictures would help confirm. To add - finally noticed your drawing link. The bottom two connections on this relay cycle this relay on and off. The top infinite switch cycles this relay when turning on the middle elements. You can disconnect and insulate so this relay doesn’t keep firing after it’s jumped out.

If this is what you mean: in the drawing below connect 1 to 1 And 2 to 2. Top to middle. Follow the path of the red and the path of the blue. When the relay activates this is the path taken. In other words jump out the relay.