LilyT Posted August 13, 2012 Report Share Posted August 13, 2012 Hi, Everyone! Does anyone have experience in using Macabee White (from Clay Planet). It's listed as a cone 10 clay that is good for wood fire. I'm curious as to what people might think about any aspect of it - throwability, wet strength for large or medium forms, fired strength, flashing, survival while firing to say, cone 11... or 13 or 14 :-). Feel free to compare to any other clays you might have used for wood fire. (Or soda) Thanks in advance for any input you might give! Warmly, Lily Link to comment Share on other sites More sharing options...
Chris Campbell Posted August 15, 2012 Report Share Posted August 15, 2012 I don't have experience with this particular clay but because I hate to chip and grind clean kiln shelves ... I would want to use a clay that matched the temp I was firing to. Why do all the work of making and lose it in the firing? Link to comment Share on other sites More sharing options...
LilyT Posted August 15, 2012 Author Report Share Posted August 15, 2012 Hi, Chris, I don't have a very good understanding of how a clay is rated and what it actually fires to. Laguna for instance has their set categories but then the clay is obviously named for something somewhat different (i.e. wood fire b-mix is in their cone 10 section, but wood firing often goes much higher and this clay can be used at those temperatures). Clay Planet's Macabee is obviously 'made for woodfire' since that's their advertising, but the bag I just got says 'cone 7-10'. I don't find the official instructions helpful perhaps because they are avoiding liability issues? So I guess your comment addresses one of my issues head-on, I'm just hoping others have had experience that will tell me thumbs up or thumbs down before I have to grind some shelves :-). I would love for a manufacturer to say : buttery porcelainoid white clay with excellent workability to medium size and fires up to cone 12-13 without bloating but matures sufficiently at cone 9-10 to avoid dampness seeping through the finished piece. Now that would be my clay! But if no one else has experience, I will post mine later (probably in a few weeks, since I only have the bag of clay and a partially assembled stack of kiln materials at present.) Macabee throws decently in the first pieces I've used it on - In small bowls to 8 inches, it is sightly less strong than Laguna's wood fire b-mix, (it is a porcelainoid clay), but smooth and pleasantly non-sticky - less smooth and more sticky than my current bag of woodfire b-mix. (more smooth and much less sticky than Laguna's cone 5 b-mix) I'm looking to throw fairly light functional ware with a smooth surface. Thanks for chiming in :-)! Warmly, Lily Link to comment Share on other sites More sharing options...
Guest JBaymore Posted August 15, 2012 Report Share Posted August 15, 2012 Lilly, Their Grogzilla bags from Clay Planet are also labeled cone 7-10.............. and I regularly fire it to cone 14. Shefield Ceramics Supply's #42 is rated as cone 8 oxidation only...... and I also fire that to cone 10 in my woodfired noborigama. Nothing beats testing. best, ......................john Link to comment Share on other sites More sharing options...
Chris Campbell Posted August 15, 2012 Report Share Posted August 15, 2012 Ok ... So here is a dumb question ... Why don't they mark the clay accurately? Surely this isn't beyond their technical ability? Is it a case of once it gets to Cone 10 it'll go anywhere? Link to comment Share on other sites More sharing options...
timbo_heff Posted August 15, 2012 Report Share Posted August 15, 2012 Lilly, Their Grogzilla bags from Clay Planet are also labeled cone 7-10.............. and I regularly fire it to cone 14. Shefield Ceramics Supply's #42 is rated as cone 8 oxidation only...... and I also fire that to cone 10 in my woodfired noborigama. Nothing beats testing. best, ......................john actually 42 is called a 6-10 recommended for ox or reduction. I've taken it to 11+ in wood Link to comment Share on other sites More sharing options...
LilyT Posted August 15, 2012 Author Report Share Posted August 15, 2012 John, That is good to know about Grogzilla. I have also fired their grogzilla to higher than labelled. (but not as high as 14 :-)). I guess it makes me nervous at first that even if my test goes well, that clay may not fire well in the future. (on the other hand, why do I figure that labelling it would make it any more reliable?) Probably the answer to Chris' question would give us more guidance. Another clay that fires to way higher than rated temperature successfully is Long Beach red. I had some of the long beach white, but it does not throw nearly as well and I've only fired it to cone 10. Link to comment Share on other sites More sharing options...
LilyT Posted August 15, 2012 Author Report Share Posted August 15, 2012 Lilly, Their Grogzilla bags from Clay Planet are also labeled cone 7-10.............. and I regularly fire it to cone 14. Shefield Ceramics Supply's #42 is rated as cone 8 oxidation only...... and I also fire that to cone 10 in my woodfired noborigama. Nothing beats testing. best, ......................john actually 42 is called a 6-10 recommended for ox or reduction. I've taken it to 11+ in wood Thanks, timbo_heff. Interesting how you can really stretch the upper range on some of these bodies. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted August 16, 2012 Report Share Posted August 16, 2012 Lilly, Their Grogzilla bags from Clay Planet are also labeled cone 7-10.............. and I regularly fire it to cone 14. Shefield Ceramics Supply's #42 is rated as cone 8 oxidation only...... and I also fire that to cone 10 in my woodfired noborigama. Nothing beats testing. best, ......................john actally 42 is called a 6-10 recommended for ox or reduction. I've taken it to 11+ in wood I think originally it said what I mentioned. But I've been mentioning to them for years that I fire it in a wood kiln to far higher heat work. Maybe they finally changed it. . best, .............john Link to comment Share on other sites More sharing options...
LilyT Posted August 20, 2012 Author Report Share Posted August 20, 2012 So I called Clay Planet last week and talked to one of the guys (because now it's listed as out of stock) and he said he'd used this himself for wood fire. He said that it flashed well and would be good above cone 10, but he didn't give me a number. I tried to get him to be more specific (as in when does it slump or bloat) but he wasn't biting. I don't know if it's policy to not give details, or they maybe don't use cones, or what? I'm not good at squeezing information out of people, lol. Isn't there anyone out there who's used it or tested it to destruction? Link to comment Share on other sites More sharing options...
btrengove Posted August 21, 2012 Report Share Posted August 21, 2012 So I called Clay Planet last week and talked to one of the guys (because now it's listed as out of stock) and he said he'd used this himself for wood fire. He said that it flashed well and would be good above cone 10, but he didn't give me a number. I tried to get him to be more specific (as in when does it slump or bloat) but he wasn't biting. I don't know if it's policy to not give details, or they maybe don't use cones, or what? I'm not good at squeezing information out of people, lol. Isn't there anyone out there who's used it or tested it to destruction? I have taken it to cone 11 in electric kiln. I have no clue about wood firing it. It can get hairline cracks in hi stress locations on detailed cut outs of slab work. I have never had a problem with thrown pieces. As far as the out of stock issue. I live near their store and last time I went to pick it up they had an unstable batch. They pulled it off the shelves -at least they don't sell it when it is bad! Link to comment Share on other sites More sharing options...
LilyT Posted August 21, 2012 Author Report Share Posted August 21, 2012 So I called Clay Planet last week and talked to one of the guys (because now it's listed as out of stock) and he said he'd used this himself for wood fire. He said that it flashed well and would be good above cone 10, but he didn't give me a number. I tried to get him to be more specific (as in when does it slump or bloat) but he wasn't biting. I don't know if it's policy to not give details, or they maybe don't use cones, or what? I'm not good at squeezing information out of people, lol. Isn't there anyone out there who's used it or tested it to destruction? I have taken it to cone 11 in electric kiln. I have no clue about wood firing it. It can get hairline cracks in hi stress locations on detailed cut outs of slab work. I have never had a problem with thrown pieces. As far as the out of stock issue. I live near their store and last time I went to pick it up they had an unstable batch. They pulled it off the shelves -at least they don't sell it when it is bad! Hi, btrengove! Thank you so much for your information, and specific insights about Macabee... it helps me quite a bit! I want to fire it as thrown pieces (and rarely do I do cutouts) so your experience bodes well for that use. What kind of work do you do - I'd be interested to hear about what you make and like and why you fire to cone 11 electric as it's not something I've really come across that before. (but then again there's so much I don't know Please tell us more about it if you don't mind! And thank you for the info about Clay Planet pulling it off the shelves because it was an unstable batch. They did tell me it was back. Good for them about not selling something known to be suboptimal. I am changing clays because I hope to find a more reliable supplier. I understand there must be strong economic pressures in supplying clay at good prices, but I've been stuck with 2 bad tons now from Laguna West and managing that as a hobbiest takes up a large proportion of my actual pottery time (not to mention I could never get my recent batch of B-mix to ever stop blistering, what a waste.) So nice to meet you, welcome to posting on the forum! warmest regards, Lily Link to comment Share on other sites More sharing options...
timbo_heff Posted August 21, 2012 Report Share Posted August 21, 2012 Ok ... So here is a dumb question ... Why don't they mark the clay accurately? Surely this isn't beyond their technical ability? Is it a case of once it gets to Cone 10 it'll go anywhere? Just a thought on why it's hard for clay makers are not more specific when they rate their clays above cone 10: It's easy to test a body in electric and gas for cone but most folks who fire over cone 10 do so in wood. There are so many factors that effect the clay in a wood firing from the style of the kiln, to the style of the kiln master, rate of climb, to reduction cycles, to fluxing from the ash, to hot and cold areas. So there is no way to guaranty what is going to happen to the clay when they can't know what the person is going to do to it. It's not possible to replicate a a firing schedule in everyone's wood kiln the way you can easily duplicate in every person's electric kiln "set kiln to fast glaze cone 9" . I try to make a note when someone tells me they took T3 to cone 14 beautifully, or the porcelain slumped at 13 so when someone asks if will work for them I can at least be able to say anecdotally, that I've heard of it working or I've heard of it not working. That way we can try to steer you with educated guesses and always with the caveat: please, please, please test it with your forming methods and firing methods before you make your whole years work with it. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted August 21, 2012 Report Share Posted August 21, 2012 That way we can try to steer you with educated guesses and always with the caveat: please, please, please test it with your forming methods and firing methods before you make your whole years work with it. Wise wise words there, Tim. Drives me nuts with students that suddenly decide to try something new and basically untestes on a large body of work....... on the last major firing for their senior thesis show. best, ........................john Link to comment Share on other sites More sharing options...
LilyT Posted August 22, 2012 Author Report Share Posted August 22, 2012 That way we can try to steer you with educated guesses and always with the caveat: please, please, please test it with your forming methods and firing methods before you make your whole years work with it. Wise wise words there, Tim. Drives me nuts with students that suddenly decide to try something new and basically untestes on a large body of work....... on the last major firing for their senior thesis show. best, ........................john I do like to hear people's exact experiences, just so I can figure out if it's likely to apply to me, or how I might choose to use it. timbo_heff, isn't the idea of using cones to replicate some standard of heat work so that firings can be compared? When I hear someone say they fired something to cone X, I expect they mean that the pot was in an area that reached that cone, and within a certain moderately limited variation. (and that the cone wasn't overly glazed by the atmospherics). Glazes understandably may be extremely sensitive to small differences, but shouldn't the body be more resilient? Can you use an example to help me understand why it might be that large ash deposits might affect certain body characteristics like bloating and slumping? I can see that if you fuse the entire foot of the pot to a shelf, the pot may crack upon cooling, but it would be pretty clear that wasn't the clay's fault maybe? john. Well, those students are testing it on work of the size and caliber they wish to use the clay on. Maybe just can't imagine how much variability there may be? I test, and when I find something that works, I use more of it, but my (admittedly much more limited than your) experience in the last couple of decades makes me feel that clay production is not reliable. In fact the studio pug at the craft center was more reliable than any of it's component parts - it never bloated, slumped, blistered, bubbled, or did any of those catastrophic antisocial behaviors of my 'pure' clays, lol. It's these horrible irredeemable failures I'm asking about. So I'm also curious whether there are any pot shards from history that are recovered with these defects showing? A fired pot is forever, right? Surely the ancient potters with much less sophisticated control of their supply lines had some errors of this time? I thought you might know some examples of this, being at an academic site, John? warmest regards, Lily Link to comment Share on other sites More sharing options...
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