Bill Kielb Posted February 4, 2019 Report Share Posted February 4, 2019 Soda firing and shelves We have been searching for a solution to the foaming issues with our old silicon carbide shelves boiling away each soda firing. My question is does anyone have real experience with the knock off bonded nitride shelves and or the super cool advancer types. All manufactures and sales folks tend to not guarantee yet are anxious to sell their shelves as the answer. At this point anyone with actual experience in the use of the knock offs would probably carry more weight than the respective sales mumbo jumbo I get. Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted February 4, 2019 Report Share Posted February 4, 2019 Bill, talk to vendors and users of refractory used in recovery boilers in kraft paper mills. The environment inside the recovery boilers is very similar to the environment in a salt/soda kiln. LT Link to comment Share on other sites More sharing options...
Rae Reich Posted February 4, 2019 Report Share Posted February 4, 2019 Weren't the old salt and soda kilns stacked without shelves? Link to comment Share on other sites More sharing options...
neilestrick Posted February 4, 2019 Report Share Posted February 4, 2019 It's been a while since I've salt/soda/wood fired, but every brand of silicon carbide shelf I've ever used or seen used does some foaming, including advancers. Some are worse than others. We had a set in grad school that would drip big blue globs if you fired too long. If I remember right, Advancers aren't all that bad. The really cheap fake Advancers don't hold up all that well in any type of firing- they warp. I have not seen or heard about the high end Advancer-type that are from Germany(?) being used in salt/soda, but I would expect them to behave similarly to Advancers. Link to comment Share on other sites More sharing options...
hitchmss Posted February 4, 2019 Report Share Posted February 4, 2019 Advancer shelves are wonderful when it comes to glaze runs/atmospheric drips (fly ash, soda deposits, etc) because of their virtually 0% porosity. Not only does the extremely small amount of porosity make them superior to other types of kiln shelves, including traditional silicon carbide, but it also has a thin glassy layer which has developed during the nitriding process. Now, I can speak to glaze runs with first hand experience. They do primarily come off quite easy with a steel putty knife, however I got a carbide tipped paint scraper, which makes getting off more stubborn bits much easier. Even having to put in a little elbow grease (1-2 mins per shelf at most), it is heads and tails better than any other shelf Ive used. In regards to salt/soda deposits; I personally havent fired my advancers in a salt/soda kiln, however I did speak at length with the technician at Smithe Sharp (his name is Marshall, wonderfully knowledgeable guy) who did tell me that using them in my soda kiln (planned for near'ish future) will be just fine. Definitely DO NOT spray the shelves with your water mix if doing soda mixed with water, and avoid dumping salt directly onto shelves. However, the "tears" or deposits which build up, will be easily scraped off with a putty knife, and according to them, the shelves will be fine to take back to your IFB stoneware kiln and no fears of vapors. I have not used the knock off advancer shelves myself. From what I hear, they perform just about as well as the advancers in regards to their flatness, lightweight, and durability. However, I do not think that the knockoffs are nitride bonded, just slip cast, fine grained silicon carbide. Thus I believe they have a higher porosity rate, and would likely perform worse when it comes to drips/deposits. I could be totally wrong on this, but this was my impression. There are a number of "knock offs" of the advancers out there, and I am seeing more and more retailers carrying their own brand (wont name names). In my opinion though, there are the imported versions which are thicker (about 3/8-1/2") and have the "relief cuts" in the corners of the shelves, then there are the same thickness 5/16" shelves which are better, but still not as good as the advancers; again, they could be just as good, and we're only talking branding here, but from what Ive gleaned, this is the case. Talking with the tech at SSFB he said that the advancers undergo two seperate firings to make the shelves; one to something like cone 16-18 to harden the shelf, and a second, much longer (like 30 hours or something) firing where the nitriding is done and the glassy layer is developed. I dont understand the chemistry in relation to the two firings, but thats what he told me occurs. I have talked to folks who did use the advancers in their wood kiln; worked wonderfully! They did not use them directly behind firebox though;too uneven temps in initial stages, and would break the shelves. Anything after first stack behind firebox is fine though. It would be nice for someone to do an in depth comparison of these shelves since they are coming down in price (ever so little, and slowly) and becoming more prevalent. Also, if you havent seen, SSFBS makes a whole slew of kiln furniture from the advancer material; beams, plate sitters, posts, etc. The beams are awesome! Posts in all 4 corners, beam on top to span as many shelves as you want. On a 3,4,5 shelf deep kiln, this now means that every shelf on that layer is perfectly in line with its neighbor, and any platters/work which spans a seam, will be perfectly flat too. Seen some photos of very long cars (30-40') using all advancer beams and shelves/plate sitters...makes me drool. Link to comment Share on other sites More sharing options...
neilestrick Posted February 5, 2019 Report Share Posted February 5, 2019 I bought a few of the cheap import shelves with the relief cuts about 10 years ago. They started warping when I was using them for cone 10 reduction, and continued to warp when I switched to cone 6 electric. They warped along the full length, and aa little bit at the relief cuts. I still have 3 of them that I only use as cover shelves. I don't know if their quality has improved over the last 10 years, but I'm not willing to buy more to find out. Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 5, 2019 Author Report Share Posted February 5, 2019 I have16 knock offs. Bought them after visiting the folks at Axner and even went to see a potter in Orlando that used them in reduction. For the 1/5 cost they have been great in the reduction kiln (Fulfilled the studio budget restrictions at the time) and are by no means as cool as the advancers but extremely functional. Glaze does not stick and they can be easily replaced several times over for the cost of the premium stuff. My hope was to find someone with experience using them in soda firing. Soda firing is so harsh on equipment that if these performed reasonably they would be a much better choice than $3000.00 for the high end stuff which likely would never be used for anything else again and quite frankly would be the best shelves of all our shelves. All information is helpful so thanks for the feedback! Link to comment Share on other sites More sharing options...
hitchmss Posted February 5, 2019 Report Share Posted February 5, 2019 maybe the manufacturer/retailer of the shelves you are interested in, can put you in touch with someone they know uses their shelves in salt/soda? Ill let you know how mine do in the soda kiln, but thats gonna be a couple of years. Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted February 5, 2019 Report Share Posted February 5, 2019 Bill, Find a 'shard' of a broken kiln shelf and set it on a wadded brick in every soda firing for the next six months. Evaluate after each firing. This will be best evidence. LT Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 5, 2019 Author Report Share Posted February 5, 2019 Thanks, that is the current thought Link to comment Share on other sites More sharing options...
Mark C. Posted February 7, 2019 Report Share Posted February 7, 2019 Bill My shelves kicking around are all mostly 12x24-here a loose idea of what I have and am using 65 advancers-use them in reduction high fire 4-5 china knock offs-some with cut out some without-they warp easy at cone 11 so mostly set aduidse these days 2-4 the newer Bailey Germany made advancers-these are pretty new a year or two now-I reviewed these here last year-use them every fire reduction 40-45 1 inch thick dry pressed high alumina English shelves-used to use these in reduction -replaced with advancers-now use in salt kiln only tons of old silicon carbide and a bunch of cordalights-never use them In my salt kiln I have had the best results with the dry pressed high aluminia one word of note I spray my salt into it in hot water in water solution so shelves like advancers do not like that temp shock Advancers do clean up easier as nothing sticks and I assume the goobers would knock right off. I have used the china shelves and they goober up good and warp as you would expect.The advancers I have not tried but will now try one (where the spray does not get) that I have so many(bought 10 recently for a deal-only 170$ each ) I like to not to have to scrape heavy deposits off sheves and anything with silicon carbide will attract salt/soda more than lower silica/carbide containing materials. The German shelves and the advancers are about the same price these days and I consider them both equals. The china shelves soak up the goo and warp so easy they are a poor choice. I love the dry pressed high alumina shelves from England (I got mine thru Tacoma Art center in 10 lots) back in the day-80-s and early 90's. the biggest drawback is they weigh 33# each Hopes this helps Bill Link to comment Share on other sites More sharing options...
hitchmss Posted February 7, 2019 Report Share Posted February 7, 2019 3 hours ago, Mark C. said: 2-4 the newer Bailey Germany made advancers I was hoping someone would chime in on this specific knockoff of advancers. @Mark C. how do you find these compare to the true advancers in cone 10-12 ox/redux? I have 21 advancers and love them; not a single complaint. I see the bailey version are about $20-30 per shelf cheaper and wondered if they were worth the little cost savings? $170 a shelf for used advancers is a good deal.....want to share?! Honestly, 65 advancers is just too many for one potter to have....let me help you by taking some of those off your hands Link to comment Share on other sites More sharing options...
Mark C. Posted February 7, 2019 Report Share Posted February 7, 2019 None for sale yet my friend. I found a guy who bought a kiln at a high school that came with new advancers. He sold kiln as he live on an island and has a smaller kiln that these shelves did not fit. He had 12 of them and cut 2 down -that was NO small task so he put the other 10 on crags list and I saw them .He sold them to me and delivered them as well. He bought the smaller advancers with my money for his kiln. Since I was on zero rush he did this in a few months when he and his wife where on vacation. people like to visit our area as its got some great features-super ocean huge trees great rivers and few people. Really nice folks who are new to pottery and doing it with gas as they only have power they generate on island so no electric kilns to speak only propane that they boat over. They plan on starting a school of sorts there. They have to boat it all over-its on an area called the delta in central Cal. I have stayed in touch and they visited me the next year at my UC Davis show in May. I have not yet used these latest 10 shelves.I'm Hording them -sorry As to the Bailey German ones I did full review of them and they are everything an advancer is with a more rounded corners. Same exact size. Maybe even a glasser surface . i say buy the cheaper ones-shipping is high on either brand -it used to be a deal if you bought in groups of 10 from Smith -Sharp I would inquire from each seller about a discount in larger groups Link to comment Share on other sites More sharing options...
hitchmss Posted February 8, 2019 Report Share Posted February 8, 2019 @Mark C. I was more joking about taking them off your hands.....there are few things that will have to pried from my cold dead hands....my kiln shelves are one of those. However, if you do ever go to sell them, Id happily buy any you'd be wanting to get rid of. Glad to hear about the bailey version being good. Agreed about shipping; when I go to Minneapolis this year for a show Im going to buy a number of advancers from the factory....no shipping costs! Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 21, 2019 Author Report Share Posted February 21, 2019 Thought I would put this up for all to see, only one firing though very pricy bonded nitride on left very economical bonded nitride in center very expensive bonded nitride on the right All cleaned very easily! very first firing for the economy model, expensive ones have been fired twice total I believe. no conclusion yet Link to comment Share on other sites More sharing options...
hitchmss Posted February 22, 2019 Report Share Posted February 22, 2019 Glad to see some actual proof and to hear that the soda vapor cleaned up easy! Thanks for posting! Id be curious to know, if you took that shelf, and put it in your ox/redux stoneware kiln, and fired it off, if there'd be enough soda vapor to flash the feet of your pots, and consequently if that meant there was enough vapor to eat into your IFB's? Would they come out looking like they have never been in a soda kiln, after one firing in a redux stoneware kiln....even though the "boils/buildup" of soda/salt have been scraped off, that residue is still there....is that just a interaction with the shelve's glass layer, or a deposit of salt? Hoping the middle "budget" shelf didnt crack the corner off during your firing! Link to comment Share on other sites More sharing options...
Mark C. Posted February 22, 2019 Report Share Posted February 22, 2019 Bill, are those 11x 22 or 14x 28s??? The other thing of note is the economy model WILL WARP over time where the other two will not Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 22, 2019 Author Report Share Posted February 22, 2019 @hitchmss None of them will ever go back in reduction, and no the corner on that one was cracked so it is the sacrificial test shelf. The boils are soda and they clean up easily. The economy shelves are never perfectly flat, the high dollar ones, very flat. This was a plain Jane soda firing, baking soda only, no reduction. The artist that fires this method prefers the subtle soft tones. The kiln can do supervised reduction and has a removable oxygen probe just for the occasion. My speculation: after close examination is that the soda will eat through all of them given time. The Nitride bonding seems to delay this significantly though, and of course make surface cleanup very easy. My further guess is that I will be able to replace the cheap shelves four times for the cost of the high dollar ones. Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 22, 2019 Author Report Share Posted February 22, 2019 @Mark C. 12X24 actually I believe. Old Alpines. Economy shelves are pretty flat but the high dollar are super flat. For wadded soda stuff not sure the high dollar are worth it for their flatness. I think we bought sixteen economy for reduction for about 600.00 and sixteen cut to size super flat super nitride for 3000.00. I am guessing we would have been better served buying new economy models and rotating the old out of our reduction kiln as needed. At best they will soda fire once per month, reduction fire maybe a bit more than twice per month. two identical Alpine HF 16s I believe. One for soda, one for reduction. Got the last one out of a school with maybe ten firings on it. Retrofitted everything including full PLC touch screen monitor for 20K including pipe, wire, labor, kilns o2 probes, high limits, the whole smack. Nice setup for the money. Funny, the high dollar shelves cost 1/3 the amount of the used (almost new) kiln. I think the kiln delivered, set and basic setup cost under 9k including conversion of the old for soda with ITC 100 on the inside. some pics: Alpines, plain soda and cool flir pic Link to comment Share on other sites More sharing options...
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