by Mary Ellin D’Agostino
Ah, a brand new package of metal clay! There are no bumps, lumps, bits of toothpick, cat hairs, or other detritus in it. The moisture is just right and I can make it do what I want it to do. It is always so tempting to open up a new package of clay for my projects. But what about all those abandoned un-fired projects? The lump of too-dry clay in the package that didn’t get quite closed? The trimmings from the last several projects? And what about the clay that got too much badger balm on it? I gave up on that bit a while ago and it is still waiting for me to get back to it. Not to mention the earlier attempt at re-hydrating old clay that I got too much water in.
I already have scads of paste and don’t have any paste-only projects planned.
With the price of silver so high, it is time to get back to re-constituting that old clay. Even the bronze and copper clay scraps have piled up and it is hard to justify opening a new package when I have so very much clay already opened.
No matter what type of metal clay you have, being able to get it back to a good working consistency is a great skill to have and there are many approaches to the project.
Rehydrating Dried Clay
The basics are to grind the clay into a fine powder and slowly add distilled water while mixing or kneading until you get it to the right consistency. Personally, I use a mortar and pestle to break up big lumps, then use a coffee grinder to turn it into powder, sift through a bit of brass screen, then spritz with water and mix. Too much water and you will need to either add more powdered clay or leave the mess open so the excess water will evaporate. Whenever I have this problem, I usually forget it, and come back after it has become too dry! LOL.
There are good instructions on how to reconstitute completely dried clay at
- Reclaiming Your Metal Clay by Maggie Bergman
- Reconstituting Dry Metal Clay by Margaret Schindel
- How to Reconstitute Metal Clay with Lisa Cain (video)
Once you have it in powder form, Hadar Jacobson’s directions for mixing metal clay are fantastic as well.
Maggie Bergman’s method is great for rehydrating whole pieces that you abandoned by putting it between layers of moistened sponge until it re-absorbs the water. Try one or more methods and see which works better for you.
Once the clay has enough (or almost enough) moisture, use the methods described below.
Too Dry to Work
Sometimes clay is too dry to work with—too stiff or crumbly—but not completely dry. My favorite way to deal with this problem (or to continue the rehydration process for dried clay) is to place the offending clay on a cut up plastic bag (this is thicker and sturdier than most plastic wraps), add a spritz or drop of water (sparingly!), fold the plastic over the clay and roll until it is flattened. Open the plastic, fold up the clay, and repeat until the clay seems to be consistent and all lumps are crushed into submission. You can add a little water as you go if it seems necessary, but use less than you think you need.
Finally, and I have never found a substitute for this step, roll and knead the clay in your (lightly greased) hands until it is the desired consistency. You will quickly find out if it is still too dry or too wet. If it is too wet, use one of your tools to scrape the mess off your hands and put back onto the plastic. Then, either add some powdered clay to the mess and go back to working in the plastic or leave it exposed to the air so it dries a bit and try again later.
Crumbly or Hard to Work
If you overwork even new clay it can become cracky and difficult to make it do what you want. Sometimes even when it has the right amount of moisture, the clay just doesn’t work right; it is overly cracky and you can’t make a coil or piece you can manipulate because it just breaks. The easy, but inelegant solution to this is to make a form that doesn’t require a lot of manipulation or finishing. A better solution is to work a few drops of glycerin into the clay. A drop or two of lavender or citrus essential oil is beneficial and will keep mold and mildew from growing on the clay.
It may help to let the clay rest and the water and/or new ingredients to meld into the binders overnight. While “resting” the binders fully absorb the water, glycerin, and essential oil and are re-activated so they are effective again.
Too Much Oil or Balm
Overworked clay often has too much oil or balm on it from your heavily greased tools or hands. This will give you the crumbly, hard to work, cracky problem. Often, if you just spritz a bit of water onto it, wrap in plastic, store and let sit overnight, the clay will be workable. The next thing to try is to add a bit of glycerin. If letting the clay rest and the addition of glycerin doesn’t work, your next best bet is to add more clay to the lump to dilute the grease. This can be fresh clay or reconstituted clay. Mix them together then knead/fold/roll in plastic until it becomes workable again. Letting it rest after mixing is a good idea.
But what about the fibers, hair, and other bits of stuff that get in the clay? If you are grinding and sifting the clay, you can remove many of these bits of fluff and stuff during the process. Little dust bunnies form and can be picked out of the clay powder with a tweezers.
Another approach that is especially good if your slip has too many fibers or contaminants in it is to add water until the clay/paste is thin enough to force through a piece of gauze (the kind of gauzy nylon used for sheer window curtains) into a clean container. I usually stretch the fabric over a jar and hold in place with a rubber band. Then I use a pallet knife to force the paste through the mesh. All the lumps and contaminants stay behind and the good paste ends up in the jar. You can either use this as paste or let it dry back to clay consistency. As for the contaminated mess left on the cloth, you can scrape it off and use it for texture, heat bits of it with a torch until they melt to create your own casting grain, or just add it to your recycle bin to be sent to the refinery.
I have found that these steps will revitalize all my problem clays. I hope this helps. Let me know if I have left anything out or if you have a different approach to solving these problems.