Best metal clays: we tested the 4 most popular finesilver clays

Will the market leader be dethroned by a newcomer?

Today, there's a wide choice of Metal Clay: from bronze to gold and silver, as well as copper, brass, iron and steel.

Fine silver clay has become a secret darling. And for good reason, as they are very easy to work and fire, and the final piece is made of fine silver, a precious metal already well known in the jewelry sector.

As these clays can even be fired with a blowtorch, they are ideal for beginners.

We tested the 4 most popular silver clays

Although the finished piece is always made of fine silver (Ag 999), there are still differences between the individual brands.

So that you can always find the best clay for your project, we at Metalclay-Shop have tested and compared the 4 most popular fine silver clays in detail:

Our test pieces

We made two pieces with each clay:

For our test, we use a fish and a seahorse.

Both were made using a silicone texture mat and were then cut out with a scalpel. After drying, the shapes were then refined with files and wet wipes. 

Fresh clay

Art Clay and FYI pastes are very similar: they are soft and easily malleable. They are light grey in color.

Prometheus and Project X pastes are slightly brownish in color and firmer. They need to be conditioned before use.The purpose of conditioning makes the clay more workable. To do this, the dough is rolled out flat several times and folded on itself. This activates the binder and softens the clay. Care must be taken, however, not to trap air in the clay during folding, as this can cause bubbles during firing.

Consistency and working time

Art Clay and FYI clays are very malleable and smooth.

Prometheus and Project X clays still have a harder consistency after conditioning. On the other hand, they allow a longer working time before drying and cracking.

All clays are highly capable of taking on fine, detailed textures. Art Clay and FYI Clay stick to the texture plate a little faster than Prometheus and Project X Clay. Lubricating the textures lightly with olive oil easily prevents them from sticking.

Warping is a frequent problem with high-shrinkage clays

Warping is a frequent problem with high-shrinkage clays.

Warping, i.e. deformation and distortion during drying, is a frequent problem with higher-shrinkage clays.

This is due to the evaporation of water during drying, which causes initial shrinkage. For parts laid flat, evaporation on the underside is prevented by contact with the surface. As a result, the part dries and shrinks unevenly.

Project X Clay's high shrinkage rate results in greater warping. In contrast, this effect is minimal with Art Clay and FYI Clay. It is usually sufficient to turn the part over once or twice during drying.

To avoid warping as much as possible, Project X Clay parts should be turned over more often to ensure uniform drying. At the start of the drying process (on a hot plate), approximately every 30 seconds.

To dry completely, Prometheus clay and Project X clay need more time than Art Clay and FYI clay.

After drying

After drying, Prometheus Clay and Project X Clay are harder and more stable than parts made with Art Clay and FYI Clay.

This reduces the risk of breakage, but also means that the parts are more difficult to sand, file and drill.

We recommend diamond files for Prometheus and Project X clays. Art Clay and FYI Clay, on the other hand, work well with metal files.

Firing

In electric kiln

Prometheus Clay 999 Silver Clay requires a minimum temperature of 570°C, while Project X 999 Silver Clay can be fired from 600°C.

Art Clay 999 Silver Clay must be fired at a minimum temperature of 650°C and FYI 999 Silver Clay must be fired at a minimum temperature of 750°C.

Art Clay, FYI Clay and Project X Clay can be fired up to 900°C. Only Prometheus clay has a maximum firing temperature of 700°C. Problems may occur at higher temperatures.

When the firing temperature of the binder is reached, smoke escapes from the kiln. This is not harmful to health, but we recommend using the kiln with a well-ventilated chamber. As Project X Clay contains more binder than other clays, the smoke generated is greater.

With the handtorch

According to the manufacturer's instructions, Art Clay, FYI Clay and Project X Clay can be torch-fired. Prometheus does not mention the possibility of torchfiring in its instructions. However, we have successfully torchfired all 4 clays.

For small to medium-sized pieces, a minimum firing time of 2:30 minutes has proved its worth. Larger pieces require longer firing times.

Art Clay and FYI Clay behave in a comparable way.

We have seen an additional effect with Prometheus Clay and Project X Clay:

1) Because they contain a larger amount of binder, the flame produced in the first few seconds (when the binder burns) is bigger, especially for Project X Clay.

2) During sintering, the edge of the part reaches sintering temperature first, with the result that the silver particles are already approaching each other while the center of the part has not yet reached the necessary temperature. As a result, the part is initially highly deformed. As soon as the center of the part has also reached sintering temperature, the parts generally return to their original shape.

We have not seen these effects with Art Clay and FYI Clay.

Shrinkage ranges from 9 to 26%

As the table demonstrates, the 4 fine silver clays have different shrinkage rates.

The photo shows the test pieces after firing. All pieces were fired for 2 hours at the maximum temperature recommended by the manufacturer. For Art Clay, FYI Clay and Project X Clay, this corresponds to 900°C, for Prometheus Clay to just 700°C.

The differences in size, i.e. the different shrinkages, are now clearly visible.

Polishing finished parts

All parts have been polished after firing. There are no significant differences between brands.

Our final conclusions

Even if the finished parts are very similar, we can see that the choice for one or the other clay depends on your personal preferences and your project:

• If you need to file a lot or drill holes in your part, we can recommend Art Clay and FYI Clay.
• Prometheus Clay and Project X Clay clay are very dense and therefore take longer to dry. They can be sculpted very well when dry.
• For small, detailed pieces, we recommend Project X 999 Silver Clay.
• If you want to bend your piece after drying, Project X Flex Clay is best suited to your project.
• If your creation contains synthetic stones or glass, it's important to fire the piece at a relatively low temperature. In this case, Prometheus and Project X pastes are best suited.