Dick White Posted August 15, 2022 Report Share Posted August 15, 2022 (edited) Is anyone having (or aware of) recent issues with Custer feldspar, or aware of any recent independent data on the material content of it? Those who have been in the rabbit hole for awhile may remember maybe 10 years ago, Custer-based glazes suddenly were underfiring. It was a wide enough problem that some folks with access to the necessary resources (e.g., Ron Roy) had samples tested by independent laboratories and found that the potassium content was significantly less than previously, and less than advertised as Pacer Corporation insisted there was no change. Those of us who mix our own glazes and know about such things, recalculated our recipes and got on with our lives. Recently, however, glazes mixed with our last bag of Custer have been running all over the kiln. There has been some slight noise in other clay groups wondering why their glazes with Custer in them are responding differently. We have a pretty smart group of peeps here - does anybody else have any insight? Edited August 16, 2022 by Min title edit Quote Link to comment Share on other sites More sharing options...
glazenerd Posted August 16, 2022 Report Share Posted August 16, 2022 Dick: Potassium (USA) historically mined in New Mexico (potassium chloride) and Utah (potassium/magnesium). More recently, in Nevada: in proximity to boron/borates. Is Pacer running their own mines, or contractually purchasing from mines? Given the fluidity: would be looking hard at boron (ulexite) contamination. Tom Quote Link to comment Share on other sites More sharing options...
Min Posted August 16, 2022 Report Share Posted August 16, 2022 (edited) Oh shoot, not again with the Custer. I had seen a few bits here and there that people were having issues with new bags of it but now that you have confirmed it Dick it really does sound like there is another significant change to it. From Pacer's website it looks like they changed ownership in 2018, maybe just maybe they will put out a more accurate analysis instead of having to rely on people like Ron Roy (or like @Kaolinwasher did in 2017, this thread). Can you use Mahavir until an accurate analysis is found? It's my understanding Custer is mined near Custer, South Dakota. From Pacer's website the blurb below, I emailed them and asked if they have an updated analysis but I'm not holding my breath. "In 2018, Pacer Corporation changed ownership and operations management. Under a new name and business philosophy, Pacer Minerals, LLC has improved mining practices, modernized ore sorting techniques, & restructured quality control procedures." Edited August 16, 2022 by Min clarity Quote Link to comment Share on other sites More sharing options...
Dick White Posted August 16, 2022 Author Report Share Posted August 16, 2022 (edited) Interesting. The company may have been reorganized, but that was 4 years ago. This change in glaze behavior is more recent than that. I too emailed them for an analysis. Most other sources of ceramic material have their analysis somewhere on their website (usually deep, you have to dig and know what you are looking for), but nothing to be seen here. My local supplier does not carry Mahavir, or I would have been using it all along. Edited August 16, 2022 by Dick White Quote Link to comment Share on other sites More sharing options...
Min Posted August 16, 2022 Report Share Posted August 16, 2022 (edited) From Pacer this morning, it's hard to read but the date on the P-325M is Oct 2020 and on the other is Feb 2021 so neither would be for the current supply. I'm emailing them back and asking if they have more recent ones. It's interesting to compare this data to Roy's. Even with the Pacer Feb 2021 data compared to Roy's most recent figures there is a "fair" amount of difference in the K2O (up) and Na2O (up). SiO2 down a little and Al2O3 up a little. @Dick White are you using it claybodies too? Ron Roy Custer spar analysis from 2012 edit: I'm pinning this post, pretty sure this will come up again. Edited August 16, 2022 by Min Pinning comment and clarity Quote Link to comment Share on other sites More sharing options...
Mark C. Posted August 16, 2022 Report Share Posted August 16, 2022 Well shoot -I'm almost out of my lifetime supple of Kingman (on last 100# bag) and custar is my next go to. Of course my 2-6 bags are old stock so that may works for some time. Hope you get to the bottom of this -maybe at cone 10 it will not be an issue? Quote Link to comment Share on other sites More sharing options...
Dick White Posted August 16, 2022 Author Report Share Posted August 16, 2022 @Min Interesting! They haven't replied to my request, but when/if they do it will undoubtedly be the same as you received. So, let's go with that. 2020 or 2021 is probably recent enough, it is well after the management change. If we look at the long history and do the numbers: pre-2000ish had 69% silica, 17% alumina, 10% potash, 3% soda (for 13ish% KNa flux) and other miscellany. Ron Roy's average for the early century bags (which is not much different from the numbers @Kaolinwashergot in 2017) had 72% silica, 15% alumina, 7.5% potash, 3% soda (for 10ish% KNa flux) and other miscellany. The new numbers are now almost exactly back to what they were over 20 years ago (and, what pisses me off, what they have been consistently advertising as unchanged during that 20 years of despite different independent material analysis). Actually, the KNa flux now is slightly higher than 20 years ago 14.5% vs. 13.2%, which goes a long way to explaining why my glazes with fair amounts of Custer are now running off the pots. Time to recalculate them again (or more likely, just go back to the old recipes). And no, I don't mix my own clay bodies, just glazes. But they do in the ceramics program at our sister campus. I will let them know if it matters , And now back to work... Quote Link to comment Share on other sites More sharing options...
Min Posted August 16, 2022 Report Share Posted August 16, 2022 4 hours ago, Mark C. said: -maybe at cone 10 it will not be an issue? Probably more of an issue at ^10 versus mid or lowfire since high fire glazes typically contain more spar. Quote Link to comment Share on other sites More sharing options...
Russ Posted August 16, 2022 Report Share Posted August 16, 2022 It seems that the ore body being mined has changed somewhat. I figure that the tile and paint industries are not having problems with the composition so they dont really give a hoot. I have switched all my glazes that contained custer to the G200eu with no problems whatsoever because of how "dirty"...for lack of a better term custer has become. Pyewackette 1 Quote Link to comment Share on other sites More sharing options...
Soilramen1 Posted September 5, 2022 Report Share Posted September 5, 2022 (edited) interesting information Edited September 5, 2022 by Soilramen1 Quote Link to comment Share on other sites More sharing options...
Ron Roy Posted October 20, 2023 Report Share Posted October 20, 2023 Hi Dick and all, I would be willing to do the research and write another article if I can gather enough samples of the latest Custer. Anyone willing to send me some just get in touch. My best advice is to switch to another spar - g200 EU looks like the best alternative for a potash spar. Cone 10 bodies were affected when the low P2O3 Custer started shipping around 2000. That resulted in cristobalite production and shivering problems and underfiring in some glazes. Ron Roy ronroy@ca.inter.net Pyewackette and Hulk 2 Quote Link to comment Share on other sites More sharing options...
Min Posted October 20, 2023 Report Share Posted October 20, 2023 1 hour ago, Ron Roy said: Hi Dick and all, I would be willing to do the research and write another article if I can gather enough samples of the latest Custer. Anyone willing to send me some just get in touch. My best advice is to switch to another spar - g200 EU looks like the best alternative for a potash spar. Cone 10 bodies were affected when the low P2O3 Custer started shipping around 2000. That resulted in cristobalite production and shivering problems and underfiring in some glazes. Ron Roy ronroy@ca.inter.net Hi Ron, I also have another analysis that was done in June 2021 for a clay manufacturer, I'll email that to you. My supply of custer is old stock so no point in sending you a sample of that. @Dick White, could you send a sample of yours? Quote Link to comment Share on other sites More sharing options...
Dick White Posted October 21, 2023 Author Report Share Posted October 21, 2023 7 hours ago, Min said: Hi Ron, I also have another analysis that was done in June 2021 for a clay manufacturer, I'll email that to you. My supply of custer is old stock so no point in sending you a sample of that. @Dick White, could you send a sample of yours? Sure, I can send a few tubs from several studios I work with that have fairly robust turnover. My recollection is that Pacer doesn't put batch numbers on the bags, so the best I can promise is it was bought from our local general supplier within the last year. @Ron Roy PM me your address. dw Quote Link to comment Share on other sites More sharing options...
Min Posted October 21, 2023 Report Share Posted October 21, 2023 (edited) Given the recent resurrection of this thread I made up a chart so it's easier to make a comparison of the various spars and their compositions. "Kaolin Washer"refers to the analysis he had done on Pacer’s Custer done 2017, link to it here. Pacer refers to Custer spar from Pacer and Roy refers to Ron Roy’s data from his chart posted above. In addition to the significant K2O and Na2O differences between the analyses what jumps out at me is the much lower Fe2O3 (and CaO but not significant) in the Pacer Custer in the 2020 and 2021 analyses. Edited October 22, 2023 by Min Quote Link to comment Share on other sites More sharing options...
Ron Roy Posted October 22, 2023 Report Share Posted October 22, 2023 Hi Dick, I don't have any G200 except for what is left that I bought before it went downhill, My Materials are almost gone - I'm not making pots anymore. Thanks for the chart Min. I still can't believe Pacer has not owned up to publishing false analysis - RR Quote Link to comment Share on other sites More sharing options...
Dick White Posted October 23, 2023 Author Report Share Posted October 23, 2023 10 hours ago, Ron Roy said: Hi Dick, I don't have any G200 except for what is left that I bought before it went downhill, My Materials are almost gone - I'm not making pots anymore. Thanks for the chart Min. I still can't believe Pacer has not owned up to publishing false analysis - RR Ron, I think the only acknowledgement we will get to infer that there was a problem is this 2 sentence paragraph buried midway down the the page on the About Us/History page on their website, "In 2018, Pacer Corporation changed ownership and operations management. Under a new name and business philosophy, Pacer Minerals, LLC has improved mining practices, modernized ore sorting techniques, & restructured quality control procedures." I don't see a current materials analysis on their public website, apparently one must request that. Whatever numbers are in circulation were "published" by someone else after getting it from Pacer, hence the 3 slightly different analyses dated 2020 and 2021 in Min's chart. You mentioned that you could get another independent analysis if we could ship you some current samples. Send me your address in a private message in the upper right corner of this page and I'll send you some. Yve 1 Quote Link to comment Share on other sites More sharing options...
Min Posted November 24, 2023 Report Share Posted November 24, 2023 Magnolia Mud Research 1 Quote Link to comment Share on other sites More sharing options...
Ron Roy Posted November 27, 2023 Report Share Posted November 27, 2023 Hi Dick, Sorry for the long delay responding to your offer. I've been very busy fixing glazes due to high cost of GB, new talc and EPK shortage. Still don't understand how to send direct to you. My email address is ronroy@ca.inter.net I welcome inquiries about clay and glaze problems. Any one who has fairly recent samples of custer spar please contact me directly. My best advice on the subject would be - don't use it. The cost of feldspar is small compared to losing work. G200 EU has a good reputation. Laguna has said they will not import Haviar spar again. Does anyone have any idea if they are activley looking for potash spar? RR Quote Link to comment Share on other sites More sharing options...
Min Posted November 27, 2023 Report Share Posted November 27, 2023 1 hour ago, Ron Roy said: Still don't understand how to send direct to you To direct message someone click on their name or avatar (on the left side of their post). This will take you to their page. There is an icon of a small envelope near the top, click on that and follow the prompts. If you have problems myself or any of the other mod’s are happy to help. Quote Link to comment Share on other sites More sharing options...
Min Posted November 28, 2023 Report Share Posted November 28, 2023 7 hours ago, Ron Roy said: Does anyone have any idea if they are activley looking for potash spar? @Mark C., wondered with your distributor status if you had heard anything? Quote Link to comment Share on other sites More sharing options...
Mark C. Posted November 28, 2023 Report Share Posted November 28, 2023 Laguna is limiting 200#s per customer of custar now. I now am fixed for life (whats left for me) with a custar supply. And also have some G200. I just ran out of my 3,000#s of Kingman I bought in 1983 last month. All other substitutes do and will cost more.. I can reach out and ask what Laguna is planning but I doubt it will be revealed. Quote Link to comment Share on other sites More sharing options...
Mark C. Posted November 28, 2023 Report Share Posted November 28, 2023 I have some new custar as can send Ron Roy some for testing if needed? Quote Link to comment Share on other sites More sharing options...
Dick White Posted November 28, 2023 Author Report Share Posted November 28, 2023 I suggested to Ron in a PM that we drop the testing idea for the time being. Pacer ceased operations as of Nov 1, so Custer has just joined the ranks of unobtainium. Their announcement suggested they may resume at some time in the future, but nobody knows why they suddenly ceased operations or when they might resume. I suppose an independent lab analysis now might be helpful for those who have some stock on hand, but Pacer's new management a few years ago was open about publishing a revised analysis of the current product, so all a new independent analysis would tell us is whether the new management was being honest. I'd like to give them the benefit of the doubt for now. As for the future utility of doing the lab test on current stock, the near-term future is none and the long-term future is uncertain. If Pacer comes back online, we can test whatever is their "new" stock. JMO Min 1 Quote Link to comment Share on other sites More sharing options...
oldlady Posted December 17, 2023 Report Share Posted December 17, 2023 dick, reading all this tells me that pacer is probably in financial trouble. maybe a bankruptcy is in the offing. the signature on that letter min shared is a lawyer. not good. Quote Link to comment Share on other sites More sharing options...
Denice Posted December 18, 2023 Report Share Posted December 18, 2023 I was checking my glaze supplies today and found two bags of feldspar. One in Kona F-4 Soda the other is Potash Custer that I bought right after the mine fire. I don't mix a lot of glazes, so I need 50 lbs of custar. Should I use the Kona and find a home for the Potash Custer or visa versus. I could also keep them stuck in a corner. Denice Quote Link to comment Share on other sites More sharing options...
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