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neilestrick

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Everything posted by neilestrick

  1. neilestrick

    Thoughts on the Cress FX-23 P

    The L&L vent can be attached to the side of any kiln. You just drill the necessary small holes through the brick, usually two or three 1/4" holes, and screw the collection box to the outer jacket. With Skutt vents, as long as the kiln stand is an open frame you can use it. There doesn't need to be a special mounting area for either type.
  2. It's either a thickness issue, or the bottom of the bowl isn't getting as hot as the sides since it's close to the shelf, which is basically a big heat sink. You could try slowing down the firing a little bit for the last 100 degrees.
  3. neilestrick

    Thoughts on the Cress FX-23 P

    You can attach any brand of downdraft vent to any kiln. Skutt vents just push up against the bottom of the kiln, the L&L can be screwed to the side of any kiln.
  4. neilestrick

    clay water content

    Clay holds water. Silica and feldspar, not so much. The less clay you have in it, the less water it needs. A porcelain body might on be 50% clay, so it needs a lot less water than a stoneware body. When I was manager of the clay production line at A.R.T, I'd adjust the moisture level of our porcelain by 1 gallon of water at a time to an 1850 pound batch. As for how much water a body should have in it, I don't think there's a number that can be assigned. Some people like softer clay, some people like stiffer clay. Some companies mix the same body two ways- one softer for schools where kids will be using it, one stiffer for potters. Your clay body is almost an equal parts body, which should work really, really well. We used a lot of that in grad school, and it's a great all around throwing body. There's no need for the PV Clay in it though. Just go 20% Hawthorn and you'll probably see a big difference. I'm a huge fan of kaolin in clay bodies. It contributes to particle size distribution, and reduces the overly-plastic and sticky feel of ball clay. I like Tom's recommendation of cutting the ball clay to 15% and increasing the EPK.
  5. @TonyC That thermocouple looks great!
  6. neilestrick

    Some free advice!

    Where I live there are plenty of restrictions for home businesses, including no signs, no customers coming and going, no penetrations through the building (venting), and the business space can't be more than 25% of the level that it's on. If I want to build a pottery shed in the back yard as a hobby, it's allowed. As a business, nope.
  7. I would rather have the kiln firing accurately, then adjust the firing schedule as needed to reach the two goals you have mentioned above.
  8. neilestrick

    Some free advice!

    Just make sure you're totally clear with the township about what you're doing. You don't want trouble down the road.
  9. neilestrick

    Tips for airbrushing underglazes

    If it's not clogging, you may need more pressure to pull it through. If you've got a small compressor, it may not be able to keep up.
  10. When we used the Talisman at A.R.T., we were forbidden to use it on a couple of the saturated blue underglazes because it was nearly impossible to get the brushes clean enough that they didn't leave blue in the other colors.
  11. @TonyC Do not remove the spacers. Just loosen the two screws that hold the TC in the block (the two screws in the middle), push the TC forward to the end of the tube, and tighten the screws.
  12. Check the TC's, load it up, and fire it on slow glaze. Or if you want to fire really fast, do custom program and fire as fast as you want up to 2050, and put the last segment at 108F/hr instead of 200.
  13. With the TC offset not correct, it's going to overshoot by approximately 18 degrees regardless of rate. When the elements shut off, they still radiate for a short time, and with an empty kiln there's nothing to absorb the heat and keep it from climbing higher. Get the TC offset corrected, then fire the kiln with some pots and see what happens.
  14. Factory setting have the TC offset set at 18 degrees. The controller is not already compensating for the 18 degree TC offset. This controller is just a Bartlett V6-CF controller with a different name on it, so not every kiln that uses this type of controller has thermocouple protection tubes. Therefore the 18 degree offset has to be programmed in for each thermocouple. The TC offset should not read zero. That will account for a lot of the overfiring you're seeing.
  15. neilestrick

    Tips for airbrushing underglazes

    Is the brush clogging due to particle size or form the viscosity of the underglaze? If it's particles size, you could sieve through a 120 or 150 mesh and see if that works better. Pay attention to how much material doesn't go through the screen. It shouldn't be much at all, but if it is, it could change the way the underglaze melts/fuses, or the saturation of the color. Velvets are pretty darn smooth, though, so I don't expect there to be much that you can't work through the screen. As for how much to water them down, I don't have a specific number, but as little as possible. As you add more water, they're more likely to settle out, as you're seeing. You may also want to try different size tips on your airbrush and see if that helps.
  16. Did you put everything back to factory settings? You should do that before changing anything else. There should be an 18 degree thermocouple offset to correct for the insulating effect of the protection tubes. From L&L: If you have Type K thermocouples and there is a ceramic protection tube then the Thermocouple Offset should be typically be set for 00.18 (18 Deg F). Also make sure your thermocouples are touching the ends of the tubes, otherwise they're further insulated from the heat. You'll need to determine if the kiln is firing hot at all temps or just at cone 6. Run a bisque with cones. If it's also hot, then you should do a TCOS. If it's only hot at cone 6, then do a CNOS.
  17. neilestrick

    Bisque at 4 vs. 04

    You can use your normal glazes, but you'll have a hard time getting dipping glazes to adhere. Brushing glazes will work better, but that first coat will still be difficult since they pots are no longer porous. It helps to warm them up a bit. Then go ahead and fire them to your normal glaze fire cone.
  18. neilestrick

    Hardening of glaze

    You only need the bentonite if you're having suspension problems. It won't help with crystallization. If the glaze works for you, then go with it. You don't really need to change anything if you're not using it on functional pieces. Reformulating may help with crystals, though. Love those heads!
  19. neilestrick

    Hardening of glaze

    @Bill Kielb You had said that Gerstley is not a good suspender. I was not meaning that bentonite is not. Sorry for the confusion.
  20. neilestrick

    Hardening of glaze

    From Digitalfire: Gerstley Borate is also very plastic and thus suspends and hardens glazes as they dry. In fact, few clays have the plasticity and the ability to retain water that GB has. A GB slurry can take many hours to dewater on a plaster batt, even in a very think layer. Thus it is common to find Gerstley Borate based recipes having no clay content. I'm not suggesting that Gerstley should be added to anything as a suspender, because it would obviously have other effects on the glaze, but at 35% it will definitely have suspension qualities, and therefore the 5% EPK in the glaze probably isn't an issue.
  21. neilestrick

    Hardening of glaze

    I was only referring to the suspension. I agree that it has other problems. The OP had suspension issues, not Grace.
  22. neilestrick

    Hardening of glaze

    The Gerstley will help keep it suspended. However if you use a Gerstley substitute it'll have problems.
  23. When I opened my shop, I spent about $45,000. $20,000 went to the gas kiln- bricks, steel, burners, venting, gas line, etc. The rest all went toward inventory (tools, kilns, and equipment), wheels for the classroom, building improvements, lease, licenses and legal fees, etc. Had I started the way my business is now set up, I could have spent half that much. But things change, and you have to adapt. I think a nice home studio, fully equipped with a vented kiln, wheel, tools, shelving, raw materials for glazes, clay, etc. could be done for $8,000.
  24. Sitters can stick. It's a mechanical system the depending upon a cone that's melting. That's why they started putting timers on them, so that will shut it off in case the cone rod sticks. I'm assuming your kiln doesn't have a backup timer?
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