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David Woodin

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Everything posted by David Woodin

  1. I think rather than taking up the forum's time it would be better to contact me off line hdwoodin@gmail.com The kilns I have didn't have a controller so I decided to buy one controller and use it to control three different kilns. I also would need a picture of the inside of the control panel. David
  2. The model I suggested and use doesn't need a protecting tube and therefore has a high response time and needs no offset for the lag of a large mullite protecting tube. If you were to go with the Omega you need a way to mount it and I can tell you what I use. The DH-1-8-K-12 is a replacement thermocouple for what you now have except it is 12 inches long you would have to cut it shorter. The other web page I couldn't open and probably shows a complete assy. with protecting tube. So yes you are getting into deep waters. If you want the mullite protecting tube, you might ask Olympic about it an
  3. It is not that expensive, 1 or 2 thermocouples some wiring, the relays are already there so reconfigure controller to zone control , If it is a Skutt talk to Mike. David
  4. Euclids recommends firing to 1922 F peep holes open hold for 8 hours. That is what I have been doing and it is almost as good as coating with ITC 100, a lot cheaper too. David
  5. I am glad to see that L & L has addressed this situation. There tests didn't mention if they tested Omegaclad which is not Inconel. It would be a lot easier to use what L&L or some of the other kiln mfg use that have protecting tubes, because of trying to adapt connections to the various controllers. One big plus for me with the Omega is the rapid response of these 1/4 inch diameter thermocouples and 150 firings is a very conservative estimate. David
  6. Go to Omega.com type in part # KQXL-14U-6. This is 1/4 inch diameter by 6" long and enclosed in a high temp.sheath I usually get between 120 and 150 firings out of this. When it fails it fails fast so the accuracy stays stable with no drift until a pinhole develops in the sheath. I use them in gas or electric kilns. Your spare from Olympic costs $45.00 this costs $38.00. As far as flaking goes you will eventually see some black area under the probe on the shelf but you normally don't but a pot under the thermocouple, and it is only into the kiln about 1 1/2 inches. You may not like the
  7. Your thermocouple is contaminated and that is what happens to a type K exposed to the atmosphere in a kiln. You need to replace the thermocouple. The T/C mounted in the top of the kiln is going to flake all over the kiln like it has. If you are only firing in oxidation you might consider using a protecting tube, but that tends to slow down its response. You don't have to be using a 8 gauge T/C. You can get a 14 gauge element in a protecting tube that would be about the same size and last longer because of the protecting tube.. Check www.omega.com Almost all kiln manufacturer's use open
  8. I asked Skutt if there is a kit to upgrade a Skutt KM1027 240 vac to zone control. Mike Sievers, mike@skutt.com answered, and yes there is. David
  9. The kiln sitter was designed as a safety device and never meant to be the primary method to shut off the kiln. That is why kilns have peep holes so you are suppose to set cones so you can see them and manually shut off the kiln when the cones are where you want them. Unfortunately it is not easy to see the cones but a high power halogen flashlight will help. David
  10. Wouldn't it be easier to add zone control to the kilns that don't fire evenly enough? I have 3 electric kilns and have made them into zone control myself and am very pleased with the way they fire. The Bartlett V6-CF series 700 controller has the capability for up to 3 zone control built into it, you need the code to change to zone control, plus parts. Euclids sells everything you need. Another control problem is due to the open end type K thermocouple which is getting contaminated, it may be cheap but not that reliable. Omega makes a much better high temperature enclosed high response ty
  11. Before the vent you had stagnent air now you have some air movement. If you want to continue to use your program, change the last hold time to 15 minutes with vent on. This doesn't explain why the cone fire mode didn't work all though you could add some hold time to it, like 10 minutes. There maybe something the Skutt tech can see from this latest information. It looks like the T/C is reading correct but there may be a problem with the cone 04 offset if the number starts with 9 it is negative, if it start with 0 it is positive. David
  12. I neglected to ask you what controller you have. If it is the wall mount and old you may not have any options that allow you to review the offsets for T/C and cone and then that is why Skutt says you need new controller. David
  13. The Skutt Tech is correct in asking you to start with a new thermocouple. One of your problems will be to determine what the actual temperature is. Technicians have the means to determine this, a brand new thermocouple takes care of one variable. It will be interesting to see if there are any offsets applied to thermocouple or cone heatwork. I have never found the controller itself more than +,- 2 deg F which is well within spec's. Too bad you are not closer to the west, this is a very interesting problem. Another question, do you use self standing cones to check heat work? Making your o
  14. There is no calibration of the thermocouple itself, but there is an offset adjustment which is usually one of the option keys on the front panel of the controller scroll to TCOS, the instruction manual tells how to increase or decrease the offset. It is best to just write down what the offset is set to for both the thermocouple TCOS and cone CNOS and think about it before making changes or call the Skutt technician. You can get into trouble. Cone offset increases or decreases the heatwork for each cone individually TCOS adjusts calibration of the temperature readings, and affects all cone nu
  15. Neil is right and if your thermocouple was reading right cone 03 would have bent to about 30 deg with 1 hour soak @ 1920 deg F. If everything was correct than you only needed 1887 deg F for i hour soak to get cone 04 to 90 deg bend. So if you want to pursue this, short of getting someone like Niel to look at every thing you will have to talk to Skutt about what you can do. David
  16. True if the thermocouples are correct and no offset. The program to 1920 actually had more heat work than the program with no hold and a top temperature of 1945. You should look at how much offset the thermocouple has and /or play around with some hold time but not 1 hour hold. David
  17. Did you have a hold for the cone firing? Your own program had a 60 minute hold what was its last ramp to 1920 F? David
  18. I think you should rethink about your firing schedules for bisque and glaze. 85C is quite fast for the last step of glaze firing and if you are going this fast than the top temperature should have been 1230 C, but since you hold it for 15 min than the top temp is 1221 C Also depending on how good the elements are it is possible that the kiln can't fire this fast. Do you use self standing cones, or make your own cone pack? David I took the glaze firing schedule from digitalfire: http://digitalfire.com/4sight/firingschedule/mastering_glazes_cone_6_firing_schedule_83.html I usually
  19. I would be inclined to change out the controller for a Barlett. The kiln itself will be fine but electronics have changed a lot in 22 years and you may be fighting problems due to drying out of compenents, parts no longer made etc. Euclids can help with getting you up to speed with a new Barlett and possibilily zone control. David
  20. I substituted Gerstley Borate for the colmanite in your glaze and made a 8 tile test and added the GB back into the glaze in 4 gram amounts, by tile 5=16 gram GB the surface was clear and glossy, tile 6=20 gram no blemish surface, tile 7=24 slight milkyness where thick no blemish, tile 8 some healed over pin holes, 8=28 grams. Self supporting cone 6@ 90 degree bend, clay laguna Amador stoneware. No faults at all. I don't know what this means in your case, clay? bisque not burning out the carbon material in clay? glaze firing too fast? Ware not dry enough after glazing to be fired? David
  21. My clay has 5% shrinkage on drying and another 5% on bisque the remainder on glaze firing. David
  22. There is a possibility that the bisque firing is not correct. With the speed of the last ramp plus 30 minute soak you are firing somewhere between C08 and C07. Also the program is too fast thru the carbon burn out area, 1000 deg F to 1100 deg F. The glaze program is also too fast for the last ramp. You should try to mimic the fixed programs in the manual for the kiln controller. David
  23. I think you should rethink about your firing schedules for bisque and glaze. 85C is quite fast for the last step of glaze firing and if you are going this fast than the top temperature should have been 1230 C, but since you hold it for 15 min than the top temp is 1221 C Also depending on how good the elements are it is possible that the kiln can't fire this fast. Do you use self standing cones, or make your own cone pack? David
  24. If you want to use less colemanite, or get B203 into limits. You could try Neph Sy 33,Wollastonite 15, colmanite 12, EPK 10, Silica 30. This has less fluxing power, but still is cone 6. David
  25. There is a lot wrong with this glaze. KNO low CAO high Al2O3 high B2903 high, also colemanite is a generic formula for Gerstley Borate. It would be better to supply B203 with a frit. You would have to abandon this glaze and start over or make a up a new formula and keep the formula within limits for cone 6. It probably spit because of the high amount of B203 supplied by colemanite. David
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