Bill Kielb

Natural gas / propane - auto ignition temperature is 482c - 649 c (1200 f) To be very safe so folks don’t create their own bomb we usually require the temperature of early (body) reduction to begin no less than 1500 f to be extra safe. No point in finding the cool spot in the kiln to only to blow up the studio. The L&L docs are for interior square inches so surface area calc. The data show for 3” walls kilns are designed in the 3.3 - 4 or more watts per interior surface area. Good data actually to gauge kilns by along with recorded losses at various temps. If you need 30,000 btuh and that burners flame length at that output or above is 12”, then the flame will impinge on the wall significantly for any shape less than 12” so to me, figure out required btuh, add your margins of safety and check burner requirements such as pressure, orifice, and flame length. Almost ALL of your heating comes from radiation, so an effective flame is key. Convection - not very significant especially at high temps.

The elements wear together so generally if it needs elements, it needs them all. Firing at cooler temperatures definitely makes a difference but really at zero outdoor temperature that’s on the order of 3-4% change to a kiln firing over 2000f. Yes, very cold especially for humans who live in a very small temperature range but most often does not affect the kiln to a large degree. I don’t want to completely dismiss the outdoor temperature though. As elements wear by about 10% most kilns begin having trouble making top temperature. So on a very cold day and a worn kiln, that 1,2,3 % from the outdoor temperature could add up to be significant. More of a function of we wish kilns were designed with more like 120% of the energy needed than 110%.

A well stocked drill index can make your orifice estimation easier. Reduction at bisque temperatures a bit difficult if I understand that correctly. We limit early reduction to 1500 f I believe to be safe. L&L has nice resources here https://hotkiln.com/sites/default/files/pdf/BTUS-Davinci.pdf for electric kilns and btu loss per sq inch interior at various temperatures which can easily be translated to watts per Square (your area here) as a guide using 100% energy conversion. Maximizing burner projection with minimal impingement maximizing the radiant area probably most important. I think I would have a good idea of the energy required at 100% efficiency and see what the burner projection or flame length at approx 150% of anticipated energy needs ends up as a start.

If you search Glazy.org for Matte, you will find many recipes. The Katz — Burke has extensive color test and ought to be easily adjusted from its present matte to semi matte, etc… by testing and increasing the silica in small increments till your desired sheen is achieved.

Generally requires new elements (240v single phase) and follow the circuit diagram for the 240v single phase model. So the cost of elements, your time as labor and misc wiring as may be required. Not knowing what you are used to or what your. Skutt presently is. To add automation with some form of digital controller then likely 400.00 - 600.00 or more in controller parts, relays, wiring and your labor to fabricate things such as an enclosure and install it all. Last things I can think of is electrical run to the kiln, maybe an electrician and maybe add a vent if you are used to that on your Skutt. Is it worth it? I guess depends on the funds available and whether you can buy the kiln you want already made. With all the bells and whistles you can have a new old kiln for let’s say 1k-2k and sweat equity. Can you find something already made for that amount with absolutely new elements, relays, etc….. probably not.

I did not look it up, I think you have the only possible, speculating we need on the order of 20 ohms to get a four segment parallel arrangement to be prox .5 ohms.

For this controller, knowing it errors anytime the actual temperature lags 100 deg f behind setpoint. If you are writing single test segment to 1000 f for instance, I would not go faster than 500 f per hour. It has a speed up and slow down function, seems a bit to learn. I think I would stick with a high speed rate no greater than their 360f degree per hour cone fire for early and intermediate segments. At top temperature most kilns struggle to make 110f per hour as their elements age, so that probably would be my fastest final segment here.

Thanks, it was a very first old piece and the lettering, sorry to say is mine and definitely looks it.

After scanning the manual, I would check that you have an S type thermocouple and your control is set to type S, else if you have a type K then the control is programmed accordingly. Mixing these two will definitely cause your kiln not to fire correctly. Worth the double check for sure. Page 21,22

It seams to match the auto fire diagram in the bottom and configured as single zone, I don’t think I would change it without a good reason. It corroded so much it’s hard to believe it ever was anywhere else. Your cleanup job looks great, I think it’s time to test to cone six. I think it should take say 7 - 9 hours ish. With no errors!

Sorry, eating lunch and typing on a calculator with sticky keys. 1 get 5.365 ohms. Did it as one long algebraic, will double check - kids, coke and calculator keys not a good mix Edit 5.425 - matches perfect and 44 amps gives her the design wattage so it ought to fire fine. The minor differences in element resistance could be partially in measurement. With the high limit set at 100f you likely will make cone 6 now with no error. The conefire schedules for 04 and cone 6 don’t exceed 360 degrees f per hour (page 20), so I would suggest not exceeding that in your manual schedules as well. It really looks like this is good order now.

You will likely need to call Euclids, the distribution of your elements is a bit odd. I’ll check the math in a few moments but please post the wattage and operating voltage on the kiln equipment tag.

Yep, Just confirmed - pg 17 of the manual. If set at 56f it needs to be 100 f. @High Bridge Pottery is spot on. Not sure how long it took to error so 100 degrees from setpoint would give it more time to make temp without the error. What ramp speeds have you been programming or are you using cone fire mode?

They look pretty decent, cleaning and retightening ok but if you can measure the elements as accurate as possible that would tell us a whole bunch. If I understand it, they all glow so if you have the means measure first and let’s see if they are in reasonable range is my thought. Put that issue 100% away at this point.

Can you just measure their resistance? Curious if any are open?

What cone are you firing to. When I used Palladium successfully it needed to be applied heavily and above cone 5 had random pinholes / blisters. Amaco called it a float glaze which needed enough thickness for things to float to the top as they said at the time. My experience, it needs the thickness, so gravity is not your friend. Maybe test tiles at cone 5. I can say it seems to tarnish over time as well. The family bragging rights Super Bowl trophy looked way better ten years ago.

If I read your timing right, I am guessing about 300 f per hour on average, which likely would be hard to achieve on only half the elements. If elements aren’t visibly glowing at about 1000f something is generally wrong especially for single zone so hopefully you are in good shape.

Way to go! Thanks, fingers crossed.

Might be crazy but probably could figure out visually and confirm with strain gauges. It might be a big flop or wildly successful at removing bubbles or even influencing glaze surfaces, textures and the way a glaze breaks in a unique way…….. interesting!

I would suggest buying kiln rigidiizer and following the instructions for best application. I looked at Axner / Laguna but believe it is available many other places. Quick video here: https://youtu.be/ncGdQvYf4gY - not the greatest video actually. Like the food coloring idea though. Instructions for kaowool rigidizer here: https://www.soundingstone.com/products/kaowool-rigidizer Looks like spray, dip, roll, pour …… hundson sprayer probably a good choice. Dont forget to use your mask for sure.

Sounds like low power ultrasonic applied at the right time might be a mobilization and coalescing vehicle. Just need to make sure the kiln doesn’t turn into vintage vibrating football / soccer game. I am thinking the mass of the ware is much greater than the molten glaze

Not much to convert - new orifice sizes ( smaller) proper regulator for the propane. The question is which is more convenient and cost effective for you? If natural gas is available in sufficient quantity, why would you convert?

I was thinking her optimum silica and alumina observation are consistent with your findings actually. For clear glazes, thinner just a common sense pottery practice really. Any thoughts of enhanced removal mechanically by ultrasonic excitation.

The difficulty we noticed and actually humans have to navigate, are the very small pressures to monitor and interpret. Linear movement of a damper changes area / draft exponentially. Minor gas pressure changes that vary the output again exponentially by nature and valves are not proportional while the kiln dynamic losses increase. Reduction was a bit difficult as well. In the end we settled to build and program a monitor that could help folks fire manually. Seeing the effect of minor changes and managing a firing rate definitely helped folks learn the techniques. Interesting project, remote monitoring and reminder timers ended up to be an important tool that got a lot of use, plus folks learned real firing rates, minimal adjustment and consistent reduction strategies. A monitor ended up a far better teaching tool than pure automation.

I wouldn’t stretch it. The Pacifica video shows them soaking in hot water though - not boiling, but hot tap water. Are you certain you have the right size would be my thought.