tb001 Posted October 13, 2016 Report Share Posted October 13, 2016 I'm finally nearing the end of the renovation of my studio space and starting to dig through the boxes of old materials I have in storage. Right before I packed everything up, I also bought a used kiln and ton of supplies on craigslist from a potter who was shutting down her studio. As I'm opening up boxes and boxes of glaze chemicals, I'm wondering if any of the basics have a shelf life. Everything looks ok, with the exception of the zinc oxide being a little chunky... Also, I know things can change in a mine over time. My chemicals are at least 5+ years old. The ones I bought from her I'm guessing could be 5-10 yrs old. Have there been any major changes in particular chemicals over that time? I'll be doing a ton of glaze testing and would prefer not to optimize a glaze for a chemistry I can't get anymore! So excited to finally be close to having a functional studio again! Link to comment Share on other sites More sharing options...
Mark C. Posted October 13, 2016 Report Share Posted October 13, 2016 I'm using materials I got in the 70's still-They work great. Your materials do not go bad. The zinc just absorbed moisture and will be fine. You can beat it up in chunks and what I use when mixing zinc in glazes is a junker shop blender.Blend some water with the zinc and add into the mix after blending the zinc and water. Yes as the earth is mined the materials change slightly. No worries There are a few exceptions like Custar feldspar has changed some but use up what you have.Its not rocket science just glaze. The shelf life is a few lifetimes or longer for most materials. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted October 13, 2016 Report Share Posted October 13, 2016 I agree with Mark. I have a lot of chemicals that are 15, 20 40 years old. They seem to be fine to me. Cornwall stone has changes but fires the same IMO. Zinc , as mark says, can absorb moisture. Some glazes change after they have been put into liquid , if they are water soluble. But that is not from age, it is from the soluable chemicals evaporating. Marcia Link to comment Share on other sites More sharing options...
tb001 Posted October 13, 2016 Author Report Share Posted October 13, 2016 Ah, Custer feldspar is the one I was thinking of I think. Any idea roughly when this changed? Any others I should be aware of? Love to experiment w glaze formulations, but just don't want to end up having a glaze I love that I can't replicate because I can't get one of the components anymore. Link to comment Share on other sites More sharing options...
oldlady Posted October 13, 2016 Report Share Posted October 13, 2016 you have not said how much of the chemicals you recieved? a few pounds or a nearly full 50 lb bag? chemists among us, would mixing the old with the new and stirring it around help balance out any changes between old and new? Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted October 13, 2016 Report Share Posted October 13, 2016 rocks are millions of years old already, a few more won't matter Link to comment Share on other sites More sharing options...
glazenerd Posted October 14, 2016 Report Share Posted October 14, 2016 Ah, Custer feldspar is the one I was thinking of I think. Any idea roughly when this changed? 1999, and again in late 2008. Was 10% potassium: runs 5-7 now. Calcine your zinc to 1800F, burn off the molecular water as well. Sieve back to dust. Nerd Link to comment Share on other sites More sharing options...
tb001 Posted October 14, 2016 Author Report Share Posted October 14, 2016 Thanks glazenerd--this is exactly what I was trying to figure out! Once I get fully up and running will try calcining the zinc as well. I used to be a scientist in a former life, so am used to the concept of most chemicals not going bad, with the exception of those that absorb water or are light sensitive or especially unstable, but I'm also used to the chemical composition being exactly what it says on the bottle! I love glaze testing and plan on doing a fair bit of experimenting, so want to be able to repeat my experiments when I need to refresh ingredients. I'd love to try some of the crystalline glazes and, if it's anything like lab experiments, the fewer variables the better. Old lady, I mostly have 5-10lb bags, other than the basics like silica. So enough to do a fair amount of testing. For most things it sounds like probably doesn't matter too much, which is great! Link to comment Share on other sites More sharing options...
Babs Posted October 14, 2016 Report Share Posted October 14, 2016 If you're starting out again, I'd be doing what OldLady said and mixing the old smaller quantities with new. Would be a beech to get a great glaze going only to run out of that line.. Link to comment Share on other sites More sharing options...
Benzine Posted October 14, 2016 Report Share Posted October 14, 2016 rocks are millions of years old already, a few more won't matter But how can you be sure? What if One million and one years is the limit?!!!...Hehe.... Link to comment Share on other sites More sharing options...
bciskepottery Posted October 14, 2016 Report Share Posted October 14, 2016 rocks are millions of years old already, a few more won't matter But how can you be sure? What if One million and one years is the limit?!!!...Hehe.... Makes 115 seem so . . . inconsequential. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted October 15, 2016 Report Share Posted October 15, 2016 ...............but I'm also used to the chemical composition being exactly what it says on the bottle! Studio ceramics is going to drive you nuts! best, ...............john Link to comment Share on other sites More sharing options...
tb001 Posted October 16, 2016 Author Report Share Posted October 16, 2016 Ha! Given my pottery obsession, my DH thinks I'm already there! It's the fun kind of nuts though! Link to comment Share on other sites More sharing options...
Mark C. Posted October 16, 2016 Report Share Posted October 16, 2016 Many make ball mills Peter Pugger make a single and a double one -very high quality The single is $1350 The double is $1450 heres the link http://www.peterpugger.com/pugmill-extruder/ballmill.html Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted October 17, 2016 Report Share Posted October 17, 2016 rocks are millions of years old already, a few more won't matter But how can you be sure? What if One million and one years is the limit?!!!...Hehe.... You can tell a rock is out of date if it has turned into clay but then it is in date for clay Link to comment Share on other sites More sharing options...
Chilly Posted October 18, 2016 Report Share Posted October 18, 2016 rocks are millions of years old already, a few more won't matter Does granite decompose and turn into china clay because it is too old to stay as granite, or is it because it was poorly made in the first place? Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted October 18, 2016 Report Share Posted October 18, 2016 rocks are millions of years old already, a few more won't matter Does granite decompose and turn into china clay because it is too old to stay as granite, or is it because it was poorly made in the first place? It is something to do with slightly acidic water disassociating the KNa and some Si from the feldspars and making/leaving kaolin. Link to comment Share on other sites More sharing options...
Babs Posted October 18, 2016 Report Share Posted October 18, 2016 Acid rain, more clay for we potters? Link to comment Share on other sites More sharing options...
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