Creating a Test Strip for EZ 960 Sterling Clay
When firing any new clay, it is important to take the time to determine the optimal firing schedule for your particular kiln. Many factors can affect the firing schedule, such as whether the controller is properly calibrated, where the elements are located on the kiln, placement of the kiln, etc. These factors are not that crucial when firing a fine silver clay that is fired to under 1500 degrees as the clay can sinter at lower temperatures and you are not in danger of overfiring.
However, when it comes to clays that need a higher firing temperature to sinter properly, the correct firing schedule is absolutely essential. Clay manufacturers do the best they can to test their clays and offer the optimal firing schedule based on their tests. However, they cannot possibly predict what each individual type of kiln will do when firing their brand of clay.
For this reason, taking the time to create and fire a test strip is imperative to avoid possible breakage or overfiring.
I have found the best way to do this is to create a small rectangle of clay, three cards thick. It doesn't need to be large and use a lot of clay. 1/2 inch wide by 1 and 3/4 to 2 inches long is plenty. Dry it completely and then fire at the suggested firing schedule from the manufacturer. Make sure you place the piece in the area of the kiln where you would normally fire your pieces. For example, if you fire on the floor of the kiln, place it there. If you tend to use a shelf and posts, make sure you use them when you fire the test piece. For ez960, it is also recommended you place the piece on fiber paper.
After it is fired and cooled, first test the piece for sintering by placing a drop of water on it. If the water sits on the surface of the piece, that is a good indication that it is sintered. If the water soaks into the piece, you should refire it at a higher temperature or for a longer period of time. If the piece does pass the water test, the next test is to use two pairs of pliers to bend the piece into a u shape. If you can bend the piece without it breaking, it is fully sintered and you have found your optimal firing schedule for the clay.
You can then fire your pieces with confidence. Just remember if you decide to fire in a different manner, i.e. on two shelves, or at a different height within the kiln, or at a hotter, shorter firing schedule, you should test again.
Announcing a Fabulous New Metal Clay
Over the past few months, (March, 2016 to June 2016), I have had the distinct pleasure of testing a fabulous new Sterling Silver clay. Created by Bill Struve and distributed by Cool Tools, this clay is an open shelf sterling silver clay with wonderful working properties and incredible post firing strength. It is called EZ960 and is 96 percent silver and 4 percent copper. I am very excited to share with you what I discovered using this product.
This clay is smooth and creamy out of the package. It rolls and textures perfectly. I use a lot of delicate coils in my work and it is great for rolling long, strong and flexible coils. It also has a long working time before drying and cracking, is very easy to reconstitute with a bit of water and remains slightly flexible even after drying. I have attached fine silver bezel cups and they adhere strongly and are fully bonded after firing. I also find it easy to join pieces with just water and the post firing bond is strong and durable.
Firing and Finishing
Bill Struve recommends firing this clay on an open shelf, no carbon necessary, to 1675 Farenheit for 2 hours for full sintering. I found that in my kiln, which is a paragon SC2, it sintered fully at 1650 for 2 hours. I ramped at full speed, and held for two hours and then crash cooled. The fired color is slightly grayer than fine silver clay, which is to be expected. I tested for sintering by dabbing the fired piece with water, which was not absorbed. I find that the clay shrinks between 10 and 11 percent when fired at 1650 for 2 hours.
I brushed the pieces with a stainless steel brush and tumbled for an hour. They came out of the tumbler with a beautiful shine. I then applied liver of sulfur patina and finished with a blue radial disk to achieve a satin finish. I love the final finish this clay provides.
This is what I am most excited about. The post fired strength of this clay is fantastic! I have long wanted to make cuffs out of metal clay, but did not feel fine silver would have the strength required. With EZ960, not only do the cuffs have the required strength, but I can form and fire them flat and bend them around a mandrel after firing. This allows me a lot of creative freedom when designing the cuff. I also created a variety of rings which I formed and fired flat and bent around a mandrel post firing. They were so easy to shape and finish and I am thrilled with the design possibilities. I have been wearing and testing both the cuffs and rings and find that they can handle a lot of use and abuse with no distortion or problems.
This is proving to be my new favorite clay. I love its working properties, the finish I can achieve and the strength it provides. I have long admired the genius of Bill Struve and the dedication of Cool tools to providing metal clay artists with the best tools and supplies to fuel their creative passion.
I have not been paid to write this review, nor was I paid to do the testing. I do believe in this product and feel it will provide you with endless creative possibillties. Enjoy. Here is a link to Cool Tools if you would like to order some clay for yourself.
I recently visited Cool Tools, where I filmed several project tutorials using EZ960. They will be released over the next few months. If you are on the Cool Tolls email list, you will receive a notification when they are available to view. I will also post a link on my facebook page and on my resources page on here on my website. I hope they will help you to expand your creative approach to metal clay in new ways. I always welcome feedback and questions. You can reach me at firstname.lastname@example.org.