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  2. Liambesaw, I appreciate your first-hand experience -- just the sort of advice I'm looking for. My understanding was that the both IFB and fiber are best used as an outside insulation to a mass-based structure for more reasonable cool-down performance and more durable structure. In this case, not seeing how the fiber would degrade much (no direct flame/ash contact, maximum temperature exposure well under its rating, etc). Do you feel that IFB by itself would be appropriate for a wood-fired kiln? Would single-course caternary be structurally sound enough? If so, I could conceivably justify the cost by using it, otherwise I'm simply not sure if I can afford to spend so much. If it needs to be double-course, then I can use cheaper used firedbricks or refractory and do fiber on the outside. My direction, if I chose fiber, would be something like this kiln by Joe Finch: http://potteryandpaintings.co.uk/kilns/downloads/ClayKiln.pdf -- the fact that normal mineral wool is fine up to 1300F or so, I would tend to do less fiber than he used and more mineral wool, since the cold-side of even 2" of fiber will be likely well below 1300F if I'm only firing my sculptures to 1850F. By my calculations this sort of kiln would be one of the cheapest possible while still highly insulative and durable. My other concern is budget as regards exploration -- even if a fiber kiln lasted only 50 firings it appears to me that it would be 1/8th the cost and represent a lot of exploration and learning for low investment, putting me in a situation where I could more confidently know what my needs were and understand the relative value of different options. ... Note this is for unglazed, low-fire sculpture to a maximum of Cone 04 (and more like Cone 08 is fine). Overall most every source for kiln building besides primitive kilns (which is really what I would build if I weren't so energy conscious) seems to be trying to either: high-fire (thus high temp demands on all components and more extreme expansion/contraction), or raku-fire (high btu, very fast, thermal shock to deal with, easy access to get work out). Meanwhile I'm looking for a rather slow, safe low-temp bisque for thick work. I would feel all the engineering would change pretty dramatically if this was accounted for. I'm not actually sure how much fuel would be saved or better results would be achieved using low or no insulation compared to standard recommendations (9" IFB) not when I fire Cone 06 with a slow ramp and slow cool down. It could be that all this fuss about insulation in my particular context amounts to 1/10th of a cord or something much smaller than the amount of embodied energy and cost in all this high tech IFB/fiber/etc. Personally, at low fire temps, I don't see why I couldn't just use a simple mix of fireclay/sawdust/etc as an insulated cob of sort. It would seem to be that it would be easy to just have a mix that begins more refractory/massy for structure/durability and moved to a higher insulation exterior (vermiculite/sawdust/paper) and then a weatherproofing exterior layer. Some expansion cracking issues to design around, but seems doable. I'd rather not reinvent a wheel though if I see no signs of others using the same approach perhaps there's a reason. I'm hoping to get something up quickly and cheaply and learn as I go.
  3. yeah but you are right back with the issue of firing to cone 10 with a cone 10 kiln. But I guess you could fore to 8 with long hold?
  4. Actually, Mark is correct. I wanted to be able to fire ^10 porcelain, but was hoping 2.5 would be enough. Thanks to both for the info!
  5. Mark I think she means if she orders a new Skutt cone 10 for mid fire electric at cone 6. If I'm right then 2.5 brick is fine.
  6. I'm pretty sure IFBs will last at least 4.3x longer than fiber in a wood kiln. Plus they are easy to maintain. Need to replace a brick? Replace it. Need to replace piece of fiber? I don't envy it. I used a gregory style flat pack fiber kiln for a year, it worked fine for a year, but the 2300 2 inch fiber was not in great shape, and that was using nice clean propane. It's not structural at all, it needs to be pinned and supported. It also tears very easily and mine got less durable with use. My last firing a layer peeled off the wall and went into a bowl I was firing, that was a bummer, it was a section about 6 inches by 8 inches and was dislodged from the turbulence from the burner. Another aspect is that IFB will hold heat longer than insulation. The insulation isn't great at holding heat. Handy if you want a kiln to be opened the next morning, but not so great if you want the look of a nice slowly cooled kiln. Those would be my two concerns. I would think hard about this because once you invest in the fiber kiln and find you don't like it, you've now wasted time and money when you could have done it better the first time.
  7. Could you stuff the burner ports after/when you shut off the kiln? With kaowool? Introduce a bit of combustibles then?
  8. Hi, @dianen, and welcome! I work in similar mode and have, over the years, developed a couple of solutions. After much searching, I finally found a comfortable chair with soft arms that are the perfect height to rest my elbows while carving and decorating/glazing. The arms are as long as the chair and level so that I can rest a board across that holds my turntable/banding wheel for close work on small pots. I also have an old rolling "computer" table, the kind with a base that rolls under your couch or chair, like bed tables in hospitals. I use that for larger pieces so I don't have to lift the pot or board when I get up. Just be careful to balance the load on it, some are more tippy than others. The height is adjustable on most, but closer to the ground is preferable for stability. When you find that chair, protect it from large persons who plop!
  9. Today
  10. Yes my pots did not crash through quartz inversion so that was a great thing. I'm unloading kikln today at 3 pm-I already took a bunch of stuff from it to outlets. This year was super for sales as Mothers day and graduation weekend at the collage where on two separate weekends-Often its the same weekend . So I made sales at a show at UC Davis far away for 3 days over mothers day and all outlets sold well that weekend as well as the next weekend when the state collage has 2,600 graduates with parents mostly from out of town visiting so sales again spike at the outlets.Checks will be rolling in and I had to restock 8 outlets as well again.
  11. I posted last-year about wood-firing or propane firing for low-fire sculpture. The responses were really helpful and I've spent a good amount of time researching and understanding my options. But now comes the hard part: making actual purchases. While I will be getting into specifics of design shortly, right now the questions I am trying to settle are more on technologies. Cost is a major concern. I have the 21st Century Kilns book and have browsed through a few other sources (Finch, Olsen and Ian Gregory). Something keeps confusing me, though. It seems that a lot of people speak as if firebricks are going to be cheaper than other options, but my experience on pricing right now seems to be radically opposite, when comparing total insulation value. First, for IFB's, the cheapest I can find somewhat locally would be $4 a brick for flats. A guy down the street who is moving and has tons of ceramic supplies is selling his pallet of IFB's at $2 a brick -- but I may or may not get in on that deal in time. Keeping to a consistent metric for the insulation-aspect: most people seem to recommend a 9" wall with IFBs. That would work out to $51/sqft for surfaces with new bricks, or $25 for this special deal. Now, for ceramic fiber blankets, my research indicates that 4" at 8# density would be roughly equivalent to 9" IFB in terms of insulation value. There are plenty of sources for very affordable fiber: ceramicfiberonline.com for example has 2300F 1" fiber at $1.48/sqft. Since I'd need 4" of that to reach the same level of insulation as the 9" IFB, that's $5.92/sqft. Even the highest price fiber blankets I can find work out to $15/sqft. So, by my math, in my market, apples-to-apples new-to-new comparison: IFBs are 8.6x as expensive as ceramic fiber! Is there something I am missing here? How could anyone on a tight budget justify IFBs over ceramic fiber when considering insulation alone? Is the market changing compared to when these books were written or, am I getting some math wrong, or perhaps am I not finding well priced vendors? Since with either IFB or Ceramic Blankets a mass-based castable refractory or hard brick interior layer would be ideally recommended for wood-firing, the fact that the IFBs are structural seems to not really yield any advantage at that level. And reusability is the similar on each. The only difference is durability, in which case neither are great performers relative to hard firebricks but the IFBs win -- but not so much that they will last 8.6x longer! or even 4.3x longer, especially if both are placed behind a hard layer and the firing temps are low-fire to begin with. Now if it would be acceptable to just use a single layer of IFB's for the firing chamber, then I could see how the IFB's do double duty compared to having to create a rigid form over which to drape the blankets -- but then again, people often manage to get away with using things like old trash cans or hardware cloth to support ceramic blanket structures. Also I've heard the argument on this forum that ceramic fiber blankets are too toxic, but I fail to see how that's of relevance in an outdoor-built kiln where the blankets are sandwiched between an inner and outer layer -- and if there is still relevance than it appears to me that, at least for low fire, there are safe blankets: ceramicfiberonline.com has a "biofibre" that is supposedly nontoxic and rated to 2012F instead of 2300F (I'd only be firing up to 1850F anyway).
  12. And can someone tell me if I *Have* to have 3” bricks in a ^10 kiln? Or can I get away with the 2.5” brick? Yes you will need 3 inch brick for cone 10 and really that is just a bare minimum .Forget about 2.5 for cone 10
  13. Wow I didn't expect so much helpful advice so quickly. Thanks everyone. I didn't realize how much clay some of the production-oriented potters here go through, so I should probably clarify... It's only about 50 lbs in total of dry and slip. It's not a huge financial loss if I have to get rid of it. I also have very little reclaim that may have some plaster contamination anyway. I talked to Clay Planet about this. I measured ~3% +/- 0.5% absorption. They mentioned it hadn't been tested in a while, and suggested adding some feldspar. That was about it though. I'm a bit concerned about trying to fix it because it might be a fair bit of testing work, and probably only relevant for this batch. I'm also not terribly excited about the prospect of fixing future batches, and not too thrilled with the Glacia in general. It's nice enough for throwing, but it's a bit dirty and flabby for slipcasting. I think I might just throw it in storage and switch to a new formulation. That being said, what would everyone suggest for a new porcelain? Is it reasonable to formulate my own, or is that a world of frustration? Has anyone used either Pier or Miller 550? Is it unreasonable to avoid Pier because of this experience with the Glacia, just because it's a Clay Planet clay? No hard feelings to them, I just don't want to waste too much more time on clays that aren't performing.
  14. SUCH good advice from both Neil and Steven. Thank you. I love the idea of firing to ^5 and then a hold (?). And another great idea to get ^10 elements. I haven’t wired it yet, so i’m Quite flexible with the breaker/ amperage. I’m still not convinced that I just don’t pull the trigger on a new Skutt 818-3. I stumbled upon a set of valuable flatware at a thrift store. If I can sell it, I’ll get more than enough to buy that new kiln. ! ! Then I would just keep the 181 for raku. Thanks to everyone for their help! And can someone tell me if I *Have* to have 3” bricks in a ^10 kiln? Or can I get away with the 2.5” brick?
  15. You should only have problems with cracked ware and such if it gets too cold in the crash, like quartz inversion temps. Beyond that things should be fine. A refire of iron reds does wonders. @liambesaw if you slow down your cooling you should be able to get the reds without having to refire.
  16. Could be a broken cone, or your sitter is not calibrated.
  17. A cone 6 kiln will only get to cone 6 when the elements are in perfect condition. That may mean only 30-50 firings. You could contact Skutt and ask them about using different elements that would allow that kiln to go to cone 10. That would mean that the kiln would pull higher amperage, though. Typically in an 18x18 kiln they pull 24 amps, which means you'd need a 30 amp breaker. You would probably need a new power cord to handle the higher amperage, and the internal wiring may need to be upgraded as well. All of that is pretty inexpensive, though, if you can do it yourself. If you got the kiln cheap, and the bricks are in good condition, it would be worth it.
  18. ya know I would test and see where you can go with it. The rule of thumb is to buy a cone 8 or 10 kiln to do cone 6 glaze load to avoid wearing out elements too fast. I've never really be able to get a definitive answer but I've heard numbers like 25% faster wear out, so instead of a 100 or so bisque and glaze firings you would get say 75 IF you replaced sooner. Also only new elements will supposedly hit top rated temp so out of the gate you will only be able to get true cone 6 for a fixed number of firings and then it will slowly drop. Even at 50 combined firings you are paying ($125 replacement) $2.50 a bisque/glaze firing in element cost instead of a dollar and a quarter if you were firing lower. You got the kiln for almost nothing and whatever electrical wiring needed will be there for the next kiln and its a 43 year old kiln so if you can get 3-4 years out of it firing mid range it seems worth the trade off of a few years potential life. I mean I am assuming you are not trying to have a 43 year old kiln last forever. Mid fire is by default called cone 6 but actually you can get there by firing lower and using heat work to get to 6. Most say about half an hour is a cones worth of heat. We fire to cone 5 and then soak for 20 minutes using an electronic controller and get a 50% bend on the 6 cone. So if you use cone packs with a 5/6/7 cones and put 6 cone in sitter to start and then keep really good logs so you can see element decline with the cone reduction and you know how long to fire and turn off if it never actually trips the cone in the sitter, I bet you can hit in striking distance of cone 6 firings and just replace your elements more often. Essentially you are getting a timed soak in a manual kiln by just letting it naturally stall below cone 6 and knowing how long to let it do that. You could also buy a digital pyrometer for $50-$75 and actually watch the stall and then time it to get to 6. I hate looking through peep holes but you go just keep it running until the 6 bends and replace the elements when that starts getting too long. I wouldn't go low fire just because you have an old cone 6 kiln without a fight. Unless you want to make low fire work that is :-).
  19. Welders goggles with a #4 lens work great, you can see cones clearly in oxidation
  20. Already starting on that because of my day job,same with a nice hump on my back
  21. That's what I mainly use it for. I'll throw mugs and pitchers and store them in wetbox all week, then attach handles on the weekend all at once. Works great! I don't have much room so I store these tote dryboxes outdoors, but a greenhouse thing sounds like a great idea for someone with room inside
  22. Don't forget the arthritic joints in hand, elbows and wrists! best, Pres
  23. I use a small green house for my mug handles. Works perfectly. I also use it for when something comes up and I can't get to my work to trim it.
  24. ...I like th' idea painting a thin line of iron oxide on the cone t'make it easier to see. Not sure who posted that now ...was it Min? Any road, it helps ...'nother helpful hint, stand up the cone packs so they are level with (in front of) the peepholes; I cut thrown tube into the needed heights and fix a lil' slab onto them... Recall to wear the appropriate protective glasses!! !!! From Bailey website: "Infrared glasses are imperative when looking into kiln spy holes. These protect your eyes from the radiant heat. (Please note that regular sunglasses are inadequate for this purpose and may actually melt.) Protective glasses may also allow you to see your cone packs more clearly."
  25. Hey! Welcome back, Preeta! I missed your contributions. What are you up to now?

  26. Thought that was a foam cooler. That's a great idea for a damp box, since it's strong, yet light. I just lightly cover my mugs, after attaching handles, basically until the handles firm up. I used to have issues with the join developing hairline cracks, when used to use magic water *and* a joining slip. Since then, I switch to only magic water, and zero cracks.
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