Does anyone know how long one can keep porcelain slip? I have two cases of it, never opened and it is around 10 yrs old. Is there a shelf life for this stuff??
Thank for any info.
I really depends on the quality of the slip. If it is Seeley's, you're probably ok. It will have settled, and quite possibly, most of the 'free liquid' will have evaporated. If that is the case, you will need to replenish it, by adding DISTILLED water to it. You will then need to mix it VERY WELL...it will take a lot of stirring. I usually turn the jug upside down and leave it for a day or so. Just be sure that the lid is on very tight. You might even want to apply some petroleum jelly around the edge of the cap, after you have tightened it, as a further precaution. Just don't get any of it into the jug. Then stir and stir and stir some more. (Don't use a power mixer (drill attachment) until you are done mixing. Use it only as a final stir.) After you are satisfied that you have mixed it well, strain it through a wire mesh strainer over which you have stretched a leg from a pair of pantyhose...no holes or runs, please! Stir it again, let set (about 15 minutes) to release any pent-up air bubbles, and it should be ready to use. I always recommend a 'sample pour and firing' just to be sure there are no contaminates. If you find any dark specks or unaccounted for pin holes (air bubbles), then do not use. There are many brands of slip out there. I'm not saying that Seeley's is the only brand that will stand up to age, but if the brand you have was at all marginal quality 'in its prime', then just discard it. Hope this helps!
Thank so much for the very helpful information. I really appreciate it.