Art Clay Silver — Metal Clay — Frequently Asked Questions

Art Clay Silver can be added to a variety of media: glass, ceramics, or porcelain to name a few. It can be rolled, sculpted, stamped, sanded, filed, engraved, drilled and pre-polished, all prior to firing. Once fired it's pure silver and can treated like any other pure silver. Exciting new techniques and products are being developed all the time.

Silver Art Clay shrinks about 8-10%, and the Low Fire shrinks only 8-9%, the lowest in the industry. This represents less of a design challenge to beginners than a product that shrinks up to 30%.

A: You can work it like regular pottery clay. You can squish it and roll is and work it with your fingers. You can roll it out flat like pastry. You can cut holes in it. You can fold it up on itself. You can make impressions in it with a rubber stamp (oil the stamp a little to prevent the clay from sticking to it.). It is totally cool.

Then, you let it dry, and it will go "leather-hard" - again, exactly like pottery clay. At this point, you can carve it or file it, if you want. (save the filings and carved off bits - put them in water to make paste) You can sand it too. The nicer you get it finished now, the less work there will be do to after you have it fired. You can get it smooth enough that all you need to do is tumble it after.

A: You can air dry it, or use a hair dryer, or a food dehydrator. With a hair dryer or in a dehydrator, 10 - 20 mins, or overnight at room temperature. You can see the clay goes a lighter colour when it is dry. (You can check to see if a piece is dry by holding to a piece of clean glass and any condensation on the glass indicates a piece that isn't completely dry.)

A food dehydrator is great - you can pick up an inexpensive one at the big chain department stores. If you have a hair dryer handy, cut a hole in the side of a cardboard box and put the hair dryer so that it blows into the box. Put a shelf of wire mesh in the box and you can dry multiple pieces without having to hold the hair dryer.

Metal window screen can be folded into great little basket-like trays for holding projects as they dry.

A: 1mm thick will make a strong, durable pendant. Remember, it will be metal after firing, so plan accordingly. To assure even thickness, you can roll out the clay between plastic slats or a stack of 2 or 3 playing cards. Mat board may also be used as it is about 1 mm thick.

Remember, that if it is too thin, it may break, and if it has a sharp edge, it can snag or cut. The final application matters too. Earrings can be thinner than bracelet pieces or rings, because they get less wear and tear. (And least, MY earrings get less wear and tear!)

Q: What is the difference between the 650

and the Regular type?

Q: What are the syringes for?

Q: Then what is the slow-dry for?

Q: What is the paste for?

A: Use it to attach the clay to itself when you are working it.

Try this with the paste. Find a smallish leaf with an interesting texture - a geranium leaf is good. Paint the paste on the back, let it dry. Continue to add layers and let them dry, until you have built up about 6-8 layers. Then fire. The leaf will burn away, and you will have a stunning leaf made of silver.

A: You can use a kiln, or torch to fire Art Clay Silver. The chart below shows the different firing times and temperatures for using a kiln. You can use any kiln that can reach these temperatures and hold them. Choose higher temperatures/shorter firing times vs. lower/longer depending on your kiln and how long it takes to reach the temperature.

Cones will not give you enough accuracy for temperature, you will need a pyrometer (a thermometer for high temperatures). A digital controller is nice, but not necessary.

A: This is easier to demonstrate than to explain, but I'll try. There are size limitations for hand firing. Don't try to hand fire a piece made with more than one pack of clay.

You can use any torch that will get the clay to the right temperature, butane mini-torches and propane torches are both popular. A torch that is designed to operate when held horizontally is a good choice, and a trigger start makes it much easier to use. These can be obtained inexpensively from hardware stores. You will also need a stop watch or a clock or watch with a sweep-second hand.

You will need to place the item on a heat proof surface, i.e. a metal table top or with a ceramic fire brick behind it. Cradling it on a piece of ceramic fibre blanket is good, as the clay goes through a stage after the binder burns off and before it has "sintered" (fused together to become one piece) where it is quite fragile.

Start by warming the piece up with your torch, moving around the piece in a circle, heating it up gently and evenly, not by bathing it in the flame. You will see a flame develop - this is the organic binder burning off. You can hold the torch aside to let this burn away, or carry on, as you wish.

Warm the piece to a orange glow - students have likened it to the colour of a creamsicle, or a salmon colour. It should be glowing, but not brightly glowing. It helps to have the room dark when you try this the first few times so that you can see the glow more easily. It also helps if your first few pieces do not have very thin places that can overheat too easily.

Consult your timepiece and time it to hold it at the light orange glow for 2 minutes. Keep the torch circling around the entire time (This will be the longest two minutes you can remember. It helps to cradle the torch on your arm so that you can hold it for two minutes.) If the piece starts to lose it's glow, move the torch a little closer, an inch or so at a time, until it comes back to temperature. If it starts to glow brightly, move the torch up and away from the item. Keep circling with the torch.

If you are interrupted or you lose the glow, just bring the piece back up to the correct temperature and start the timing again. You do have to time it for two minutes continuous, not total.

When the two minutes are up, extinguish the torch and let the item cool. You can use tweezers to move it to a cooler part of the firing surface. Let it cool for 5-10 minutes before handling. It will now look exactly like it did before you started, but if you tap it, it will sound like metal.

Art Clay Silver - Speedfire Cone System - Kiln-less firing for Art Clay Silver (1)

A: Grab a brass brush and give it a buff. See the silver coming up? Cool, eh? For many pieces, just brass brushing will give a fine look to it!

You can burnish it with a hard item, i.e. an agate burnisher, to give a high polish to raised or smooth areas.

If you have a tumbler with some steel or stainless shot, you can tumble it for a few hours or overnight to get a lovely high polish finish.

If you are familiar with jewelry polishing, you can apply those techniques too.

A: For that, you want to use the Low Fire clay. The Low Fire Clay fires as low at 1200 F ° (650 C) - so that you can fire it without melting the glass. You do have to use a kiln, as you have to raise the temperature of the glass slowly and cool it slowly too, so that it won't shock and crack. This is called annealing.

A: Cubic Zirconia is fine, lab-grown gemstones are fine - you need flawless stones that can take the heat. Other stones - it is a good idea to pre-fire them to insure that they will not change in the kiln. Some stones will change colour with firing. Fragile stones like pearls, opals, turquoise, amber, will not work.

From my test firing notes: Hematite seems to work fine, tiger eye goes reddish and turns to "hawks eye." Reconstituted turquoise turns to white powder. Rose quartz cracks and falls apart.

Q: What about making a big hollow shape?

A: Cork clay is excellent and has consistent results. You can shape it, and use it as a base to create hollow forms. Paper and pulp products like paper clay are also an option. Always check before firing anything, high temperatures can produce unexpected chemical reactions.

A: Repairs can be made with Oil Paste, which allows you to join fired pieces back together. You can also use Oil Paste instead of flux and solder.

A: Liver of sulfur (which is a very old-fashioned name for a compound of potassion sulfides) has been used to patina or antique silver for centuries. You can add a small piece (pea-sized) to a disposable cup of hot tap water and stir until dissolved. It will be bright urine yellow, and stink of rotting eggs -- charming, eh? Suspend, (if you can, otherwise, use tweezers,) the piece on a wire, and dip into the mixture. Watch it change colour. Pull it out when you have a colour you like and rinse and wash under running water to prevent the colour continuing to develop. You can put it back in and re-dip it. Colours will develop starting with yellow, gold, blue, purple, copper, blue-black, black - not necessarily in that order on with any degree of predictability or control. If you want two pieces to match, dip them at the same time. Hotter water, stronger concentrations, pre-heating the item in hot water, all change the way it works. Never boil the mixture. It can be stored in a cool dark place (i.e. the fridge, if you dare!). You will need to re-warm it before using again.

If you hate the effect, hit it with the torch lightly and it will go away. You can polish the item to remove the effect from the high points. This is a great way to show the detail on a design. The Liver of Sulphur does penetrate into the silver and makes for a quite durable finish.

Q: What is the Overlay Silver Paste for?

A: This paste has a higher concentration of silver, and can be fired at the low-fired temperatures. Use it to decorate ceramics - it can be fired at lower temperatures than many glazes, so it can be used on a fired piece without moving the glaze.

Or, you can paint on glass and fire it at a temperature low enough to not slump the glass.

This is a portrait of my dog, painted on regular window glass (float glass) and fired. The intense yellow halo is an effect of the silver fuming the glass. Some glasses are more prone to this than others. Experimenting with window glass, bottle glass, stained glass scraps, often lead to interesting results. I personally think this is pretty cool.

A: It helps, but no. There are also some excellent books and teaching videos available. The intrepid can leap right in with the information they find here too.

But we have classes, and online projects too!

A: That's true. But this is less expensive in terms of equipment and time. You can make genuine silver jewellery in your home in an afternoon. Think of all the equipment that you don't need. You don't need metal saws and drills and files. You don't need wax carving tools. You don't need to have the casting equipment or you don't have to wait days for sending a piece out for casting. You don't need polishing equipment. Jewellery making equipment is expensive.

You can also use this to achieve naturalistic and organic shapes that would be impossible to get using traditional techniques.

Q: Can you answer other questions about it?

Of course - there is a very excellent online mailing list at http://groups.yahoo.com/group/MetalClay

For Ontario, there is the fledgling group Ontario Art Clay Addicts, who are currently meeting at beadFX and will be developing a blogsite.