Can ceramic greenware survive freezing temps?

[Christy 437 in SoCal]

My mother was an avid ceramic creator. She taught ceramics art at the local senior center for years and so acquired loads and loads of molds, glazes, and paints and everything else. Think hundreds.   She passed earlier this year. I know nothing of ceramics.

All her stuff is located at our cabin at 6700 foot elevation where winter temperatures get well below freezing for several months and snow.  All the molds and some greenware (is that the term for something fired before painting/ glazing?) are in a shed, no heat.  Will the freezing temps do any harm to either the molds or the greenware? Paints and glazes and slip(?) containers are in the house. Could they go out to the shed as well? 

 Thanks in advance for any help and answers to these questions. 

[Babs]

Greenware term used for totally unfired ware.

If what you are asking about has bee  once fired this is bisqueware anx would be fine if kept dry.

Not knowing if colours and glazes have binders, cant answer that . Freezing causes expansion so full containers may split.

[Bill Kielb]

9 hours ago, Christy 437 in SoCal said:

Will the freezing temps do any harm to either the molds or the greenware? Paints and glazes and slip(?) containers are in the house. Could they go out to the shed as well? 

In my experience more than likely freezing those items will damage them. Dry molds, no. Glazes, very good chance they will not perform well or mix well afterwards. Greenware, if any moisture, yes, very likely will be affected. Plus as above, as water based things freeze they expand, so broken containers, etc …..

[Callie Beller Diesel]

I used to have an unheated garage for a studio for many years, and am familiar with freezing ceramic materials.

If something is fired before painting or glazing, that is bisque ware, and yes it should be fine if left in a dry shed. If you want to do anything with it yourself, be sure to wash it off and let it dry for a day or so to get rid of any storage dust.

If your mother had used the moulds to cast some items but hadn’t fired them for the first time yet (this is greenware) they also have a chance of being all right. The pieces would have had to be bone dry before they froze for this to happen, or not had any chance to reabsorb any moisture and then freeze. If a piece did freeze before it was dry, you’d know about it. They disintegrate quite spectacularly once they thaw. If you’ve ever seen a piece of greenware be reclaimed in a bucket of water, it looks like that. Dissolved into a pile.

Glazes *can* be reconstituted if they freeze, but it’s a LOT of work and boring stirring and sieving to get every last little tiny lump smoothed out. And that’s with ones I mixed myself that didn’t contain binders and other things that are found in purchased brushing glazes. The binders will make it more difficult. Acrylic paint is much like house paint, and if it freezes, there’s no saving it. So if they haven’t frozen yet, keep them from doing so.

Plaster moulds should be fine, but again keep them sheltered from moisture. If you’re looking to get rid of them later, choosy slip casters may not want them if they’re doing heavy duty production. Moulds do loose their efficacy over time and if stored improperly. However someone looking to do some small scale things or to play around will be able to use them just fine. They typically will have no resale value.

[Christy 437 in SoCal]

Thank you all so much for your replies with such good information. Now my question is, how do I tell the difference between something that's been fired and something that hasn't been fired, especially if there isn't any paint or glaze applied yet? There are pieces that are white and some that are more light gray in color. I'm thinking the whiter pieces have already been fired, but that's a guess on my part.

I found boxes of unfinished pieces in the garage (unheated), in the house (heated), upstairs of the house (somewhat unheated), and sunroom attached to house (unheated). My mother lived with me for the past 3 years so these pieces have been either in the house or in the garage areas for several years. Now that she's passed I'm trying to figure out what to do with all this, without ruining any of it, as I look for whatever options there may be. 

 

[Babs]

Flick your finger at them bisqued will ring ,unfired i.e.greenware won't.

Small piece dip in water, bisque change colour, think terracotta plantpot, unfired will darken and soften and be spoiled by process probably.

Feel is different too.

 

[oldlady]

greenware is just dry mud so it will scratch easily.  bisque will have a sound if you flick a fingernail on it.    if everything is white, the brighter white might be bisque so try the fingernail trick.

[LeeU]

You could offer everything---the whole bundle, no cherry-picking---for a reasonable low price. Someone interested in the best will accept the "maybe's" if the price is low. I've found the "all or nothing" approach to be effective when I have a bunch of mixed quality items to sell.  In my area, interested potters have been OK with taking it all, at a decent price, in order to get the most desirable items. I gear the total price to cover what is fair for the best items, so some of the not-so-great or dubious things are close to "free". It's a win-win--the purchaser gets "extras" for their money and I get all of it gone.