Jump to content


  • Posts

  • Joined

  • Last visited

Everything posted by Hulk

  1. Am brushing on red and white slip (clay blunged with water, then sieved) over contrasting clay w/o issue ...so far.
  2. Wollastonite CaO 48% SiO2 52% LOI (1000C): 0.5% (Vansil: 1.6) Whiting CaO 55% Traces MgO, SiO2, etc. Which one? Digitalfire lists several; LOI ranges from unspecified to ~43%; GlazeMaster lists Whiting with 44% LOI The tin/chrome red I'm using* includes twenty parts whiting; it goes on well, melts well, doesn't run, and I'm not seeing any pinholes over any of the clays I've tried. It's been a great glaze (so far) - one of three that I'm stirring, sieving, and applying each glaze fire (Lakeside Pottery's Clear Blue and Bill Van Gilder's Rutile Green be t'others). This comparison may help me, however, as I've just over five pounds of whiting left, and most of a fifty pound sack of Wollastonite, hence juggling the recipe for Wollastonite may be a good exercise! *Credit local JC Ceramic lab for the recipe - which is same as "Chrome Red" per John Britt.
  3. Perhaps Raw is curious about the brown stuff with sparkly golden bits in it? ...on the rim of lowest right piece, and following the clay contours of several others; looks to be brushed on, to my eye. Ah! In the higher res images, looks like the brown streaks with the sparkly golden bits is indeed a streak of marbled clay.
  4. I've covered work in progress with an inverted container without issue; I've several two quart, gallon, two gallon, and five gallon buckets stacked up in the studio for just that purpose. Should loss of moisture be at issue, a shot or two or three from a mister loaded with water, as necessary, does the job. As for your Masonite bat, yrmv - my powderboard bats are 1/2" and 3/4" thick, and although they haven't warped yet, the finish is wearing off, so I don't leave work sitting on them any longer than necessary. I've enough material to make another twenty bats; when they're done, I can refinish the worn ones. I've given them a good soak with oil stain, allowed to fully dry, then finished with varnish, which holds up for a year or so, then begins to fail. Perhaps I'll try a different finish next time.
  5. Brian Jensen's "Gloze" - looks like it is no longer produced/available, however, see Glow in the Dark Glaze for Ceramic Tiles (glo-net.com)
  6. Stopped at a clay supplier on the way home from points north yesterday, got fifty pound bags o' C-98 and Gerstley Borate - that much talc may be all I ever need, howevah, I hope to go through all that GB...
  7. I used to believe myself rather an expert on transitioning from raw beginner to low intermediate level, on account o' that's where I'd just been. Now that transition is further back ...every day. Perhaps now I'm rather an expert on the very long transition from intermediate to advanced intermediate? Any road, the web of clay at the wheel head - where the base of the wall is - will respond to pressure, as Pres points out. It takes quite a bit more time and pressure to get it moving (compared to up and away from the base) however, likely due to the stabilizing influence of wheel head contact and the base layer of clay. See Bill Van Gilder's throwing video clips - note how he uses his thumb and/or finger tips to manage the web. I use the side of my index finger to form an initial groove, then I'm turning same index finger to move the shoulder of clay up a bit (pointing down and in) afore beginning the pull - hence my fingernail is not touching the clay, nor the wheel head*. Pulling walls, looks like lots of potters work a tapered profile, where the taper diminishes as the wall rises. Too thin or thick at bottom, middle, top, at each stage of the process, my guess is we each experience the several fail scenarios and learn, eh? I've found exploring "big" and "small" to be a good learning experience. "Big" for me is over 1200 grams or so, and "small" is throwing hollow knobs for jar/teapot lids and kiln filler bud vases. Big requires more patience, larger contact, and some adjustment on managing the taper; small requires a light touch, and fingertip contact with the clay. The overall process is about the same, methinks. *fingernail wears away rather quickly, and doesn't grow back fast enough, hence, I'm learning to keep my fingernails off the moving clay when centering, opening, pulling, finishing.
  8. I'd still make a case for 10x batch - ten times the recipe (if the recipe total is near one hundred) - where the objective and the action are same.
  9. The clear blue I'm using - Lakeside Pottery Clear Blue - calls for 1.6 Cobalt Carbonate; likely it's too blue for you Lady, however, it might serve if less colorant were used. I find it behaves very well at reasonable SG, with a slight adjustment for thixotropy. The recipe is on their website. The premade blue I bought is very pale, which makes sense, given the price o' cobalt. Sizing up and down a batch that totals "100" is challenging enough - recipes that total other numbers, e.g. 102, 106, 97.6, a bit more challenging, particularly if the objective is a round number. I'm sticking with batch number; when I make a "thousand" gram batch, it's really a 10x batch, and hence, a six thousand gram batch is 60x batch. A tool, where the original recipe is entered, and the scale up/down value, which then spits out the result might be handy? Two points here - 1) Where the objective is a half batch, tenth batch, ten times batch, twenty times batch, etc., the math is ...more straightforward; 2) there are tools for that. A spreadsheet could work. The ideal recipe calc tool may be a friend or acquaintance that crunches the numbers for you. I'd do it.
  10. I'm seeing that the calculated coe values don't necessarily line up when comparing very different glazes and their behaviors on the same clay bodies, however, when looking to tweak a glaze (to limit/eliminate crazing - haven't had the joy of shivering yet), then I'm finding the calculated coe very helpful, where I've lowered two high expansion oxides, increased low expansion oxides, and bumped up the boron a bit get a lower calculated coe, and less crazing ...then more changes, lower coe, even less crazing, more adjustments, aha! fitted glaze. A bit of lithium can make quite a difference; I'm using petalite, was looking to avoid the foaming, and it was inexpensive as well. Magnesium (via talc), also a handy low expansion oxide...
  11. "...a clear or white liner glaze" that's durable, smooth, doesn't mark, nor craze. Aye that.
  12. yep - inside and outside diameter, and height. Maybe start with a few drops of Liquid Wrench on those bearing seats; from there, if they don't tap out, a smidge of heat (a smidge I say!), evenly applied. Good luck - please report back.
  13. Hi YuOr! That kiln is about 2.5 cubic feet? A modest size, yet capable of producing significant waste/excess heat, and hold enough work to produce significant fumes as well. If you go with the basement, I'll suggest a powerful venting setup to remove fumes and excess heat from the space. The outflow required means a way for "make up" air to flow in will be necessary - make sense? You'll have to provide power; you might consider allowing for a larger or second kiln when you run the wire, then select the breaker appropriate for the current load... First ("bisque") fire isn't as hot, but typically takes longer, as time to drive off moisture, then burn out "organics" is allowed - seven or eight hours - or more. Glaze fire typically ramps up faster, as little as five hours? My setup takes longer though... I don't leave the house until the next day - even then, it's still hot enough to burn paper.
  14. Hi Mad, You might get a flurry o' response on this one! I'm saving clay and glaze. Clay - all trimmings, oops, throwing slop, and clean up (excepting from the floor and/or otherwise contaminated) for reclaim. I add a bit of Nerd's reclaim mix. Glaze - all clean up, wash offs, wipe offs, and so on go in a settling bucket; I'm pouring off the clear and watering trees in the back yard (which don't seem to be negatively impacted). The resultant sludge, screened, then adjusted for specific gravity and thixotropy, actually behaves well - it's a grayish blue. Next up may not work out, time will tell ...it will have more chrome, as I've added tin/chrome red to my pallet... I'm not planning on putting any metal oxides (coloured glazes) out in the environment. May I recommend this forum (a treasure trove, to be sure), also Tony Hansen's website (https://digitalfire.com). Just Hansen's take on adjusting glaze SG and thixotropy changed my outlook on glazing, aside from all else I've gleaned from his site. From there, so much to choose from; I like Peterson's The Craft and Art of Clay - her explanation of unity clicked for me, there's lots of pictures too. Watching vids was a big thing for me, the first few years (I'm in year four now) - there's a thread on recommended vids here somewhere. Each does things a bit differently; I've found it helpful to watch, then re-watch after a few months...
  15. Hi NP! Other side, indeed - looks like rusted through from within; if that jacketing is at all structural, there may be integrity problems in the offing. Does the kiln have any provision for venting the interior atmosphere whilst firing (to control build up of caustic/corrosive gasses ...and moisture)?
  16. Good question! Responses likely to range from reclaiming is a waste o' time to buy the best mill you can afford, in stainless. Once you're caught up, will you be comfortable reclaiming manually at the rate you generate? If I had a pugmill, I'd definitely use it to soften (add a bit of water) new clay, however, a new kiln will likely be next major expenditure for me...
  17. Hello again Thiamant! What type of gun are you using there? Typically, those spraying glazes are using an HVLP type setup - inexpensive (the cheap ones), easy to clean, less atomization\waste (larger droplets). I've sprayed glaze just a few times (at our local JC ceramic lab), just for fun. I thoroughly sieved, then watered down enough glaze to fill the spray gun reservoir about half way, then gave it a test shot, just a blip on a ware board - too dry. From there, a bit more water, voila, a good fan of wet, but not immediately running. Spraying the wares, I went with a light coating, then let it dry a bit, then another coating. It's important to plan for pointing the spray fan directly at each surface, e.g. curved surfaces, under handles, etc. The pieces I'd selected for the trial had been fitted with small triangles of tape, so I could check the thickness of the dry glaze by carefully peeling back the tape. The resultant triangles - call them accents! Looks like your glaze film wasn't wet enough to lay down smoothly. Tape can be a good friend, also balloons. There are several threads here on glaze spraying - try searching "hvlp"; perhaps experienced sprayers will chime in as the day wears on...
  18. Hi Nina! Good question - perhaps some of the regular forum contributors will weigh in later. I'd dampen the cracked area with a wet brush, then fill the cracks with slip (same clay, but without the paper), repeating if the cracks show once the dry. That said, no guarantee the cracks wouldn't re-form and/or get bigger; I've had some luck with filling cracks afore glazing and final fire, however, they were very small and not structural flaws ...yet. fwiw, looks like a level or two bigger than hairline.
  19. I'd tried a bag of Aardvark's Cassius Basaltic; it does come out so rich, smooth, dense! Suggest throwing/trimming medium to thin, thorough bisque with ample oxygen (I'm running a powered kiln vent). I held at 1500F for thirty minutes on the way up and down. Try cone 5 target for glaze fire, drop 100F and hold for thirty minutes.
  20. A friend wanted red. Now I'm so thankful! I'm committed to liner glaze for all food contact, that's two; keeper colours include clear blue, variagated (rutile) blue, rutile green, tin chrome red. There's testing/practice/development involved with each one, hence, starting out, one has none, eh? You might begin with dialing in liner glaze(s) and a colour or two. Some folks recommend one glaze, then add color from there...
  21. Ideal, hmm... Separate, but nearby/adjacent to studio, separated by solid door* - wide enough to roll ware cart through - level, smooth, and common (roll to/fro without impediment) floor. Sufficient shelving to store at least three kiln loads; fitted with a window, doorway to the outside, overhead venting with variable speed control, and downdraft kiln vent. Sufficient space, power, and venting capacity to add another seven cubic foot kiln. Counterspace for at least half a kiln load. Pest resistant, dry, good lighting, camera system, smoke and CO detectors, three fire extinguishers (two outside, one inside)... ...*very good noise control - hat channel hung drywall, insulation, labyrinth/muffled intake and exhausts, etc.
  22. Aye that. Am using home built downdraft on my seven cubic foot Skutt kiln, which I built, relying heavily on design suggestions found online (which I'm not finding just now). The fan pulls mostly from ambient, which mixes with the small stream of superheated air from the kiln - key point, mixes, which reduces the heat (and caustics concentration) considerably. The box has typical sliders for adjustment. I bought an inexpensive inline fan; it's weak, just strong enough to do the job. When it eventually fails, I'll replace it with something stronger. I didn't expect the kiln vent to reduce the heat load at all, however, I did expect the fumes to be much better - success there! However, there was still enough fumes that I wasn't comfortable hanging out in the studio whilst firing, and lots of heat, hence the overhead system, which we also built, using the top from an old patio heater, a 400 cfm fan and six inch ducting. The overhead system doubles as a dust catcher for glaze mixing.
  23. Looks like the Rohde HTM500 has a belt driven wheel head, rather like the Skutt in my workshop ...which does run on a bit after shutdown, however, progressively more/less in relation to the speed it was running when shut down, which is likely related to the rotating mass of motor, pulleys, and wheel head - more speed, more momentum to wind down. My wheel's controller board (Minarik PCMXP) does have adjustment for Acceleration/Deceleration (ACCEL/DECEL), which is set to the minimum from the factory. As you are not seeing less wind down time at minimum speed, could be the Rohde controller board has a similar setting, not set to minimum. I'm not finding what Rohde uses for a controller board. The "drive" boards for small DC motors have a somewhat universal set of adjustments; ACCEL/DECEL is may not be one of the most common/core adjustments, but it is common. Short answer - normal. As for the footpedal spring back, close inspection is about all I can offer there - not finding any detailed drawings/specs on that either. My pedal relies on friction, hence, I can pull off my foot without changing speed, however, I'm comfortable with leaving me foot on the pedal! I'm seeing Rohde is fairly responsive; you might have some luck contacting them for info about your control board and foot pedal adjustments... Please do post back with your findings!
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.