Thursday, March 29, 2012

Sterling Silver Test 1- Firing the Clay

by Janet Alexander
Technical Advisor

Questions, questions, questions! It seems the more I ask questions and get answers, the more questions I have!
In the next six months I will be testing different aspects of the new PMC Sterling Silver metal clay. This is the first post. I want to explore various methods for firing this clay. There has been a lot of buzz about speeding up firing time, mostly because of classroom constraints. When it takes over 1 1/2 hour to fire the sterling silver clay, it makes it hard to have an afternoon class about this new clay.

Let's start with the recommended firing profile. When and where you have time, this is the way to go. According to Mitsubishi, the recommended firing schedule for PMC Sterling Silver is a two step process. Fire the dry clay in open air on a kiln shelf for 30 minutes at 1000˚F (538˚C) for at least 30 minutes, longer for thick pieces. The second step (after cooling the clay) is to transfer it to a stainless steel container, surround it with ½” of activated carbon (at least ¼” apart) and fire it again at 1500˚F (815C˚) for at least 30 minutes.

I fired some base-line test pieces using the recommended procedure. Phase-1 took 43 minutes. This includes the time for the kiln to heat up to temperature and the 30 minutes of soak time at 1000˚F (538˚C). Phase-2 lasted approximately 51 minutes (not including cool-down time). All my tests using the recommended firing procedure came out perfectly! I was able to dome a disc and bend a link without either of them breaking. With that said if you are working on a special piece and want to make sure it fires properly, use Mitsubishi’s recommended procedure.

With my testing, I wanted to find a quicker way of sintering the sterling silver clay. In my first set of tests, I used a 50g package of PMC Sterling Silver metal clay and created five identical oval pieces with their centers cut out (35mm x 20mm and 4 cards thick). I only changed the process for Phase-1 and tried a variety of methods, shown below. All pieces were fired together in Phase-2 using the recommended procedure. This is what I found.

Test 1- Light the clay on fire
In my personal blog, a reader commented that she used a torch for phase-1 (thanks PPennee), so I tried her technique. I lit the clay on fire with a torch and then pulled it way allowing the clay to burn. If it went out, I re-lit it until it no longer smoked when heated. It’s interesting; while holding the torch on the clay there is no smoke. Only after I remove the torch does the clay burn with a flame and smoke.

The Specs
Weight after complete firing (both phases): 1.6dwt
Measurements after complete firing: 30mm x 18mm
Phase-1 time: 1.5 minutes
Sintered: Yes – bent nearly in half.

Test 2- Hadar’s Method
Hadar Jacobson, who tests and makes base metal clays, designed a faster phase-1 for her clays. She uses a camping stove and a stainless steel bowl with activated carbon in it. She places the unfired dry clay on top of the activated carbon and then covers the bowl with a fiber kiln shelf that has a hole in its center. She fires it until there is no more smoke coming out of the bowl and then places it in the kiln for the second phase firing. In this instance, I used her phase-1 technique and then Mitsubishi’s phase-2 technique.

The Specs
Weight after complete firing (both phases): 1.65dwt
Measurements after complete firing: 29mm x 19mm
Phase-1 time: 10 minutes
Sintered: Yes – bent nearly in half.

Test 3 – Mitsubishi’s Procedure

The recommended procedure.

The Specs

Weight after complete firing (both phases): 1.70dwt
Measurements after complete firing: 29mm x 20mm
Phase-1 time: 40 minutes
Sintered: Yes – bent nearly in half.

Test 4 – Torch for 3 minutes
I heated the piece with a torch for 3 minutes. I heated it to a very dull red, like when annealing metal on a fire brick, allowed it to cool, and then completed the second phase.

The Specs

Weight after complete firing (both phases): 1.85dwt
Measurements after complete firing: 30mm x 19mm
Phase-1 time: 3 minutes
Sintered: Yes – bent part-way but broke sooner than the others.

More Questions
I had more questions after completing these tests. I made four discs 18 mm in diameter and 4 four cards thick.
  1. Does the clay shrink any more with longer firing?
    I fired disc #2 per Mitsubishi's instructions for 30 minutes. I then fired disc#3 per Mitsubishi's instructions for 2 hours in phase-2.
    Answer: both discs were the same size. They both measured 15.5mm after firing.

  2. Is the torch fired (in phase-1) clay less strong than the recommended firing technique?
    Answer: no.
    I re-did the test with disc #4 and successfully domed it. I did however anneal the disc after doming it a small amount and then proceeded to dome it more.

  3. What happens if I only fire the clay on the kiln shelf at 1500˚F (815C˚) for 1 hour?
    Answer: It doesn’t sinter (see Photo#1). The outside layer is metal and polished up to a silver shine with a brass brush but it broke very easily. The inside is dark gray and the outside is silver. I did learn though that it can still be sintered by completing the two phase process.

    Photo #1 left piece is not sintered.

  4. What happens if in phase-1 I fire the clay on the shelf for just 1 minute at 1000˚F (538˚C) and then complete the recommended phase-2 procedure?
    Answer: It doesn’t sinter.

  5. What happens if in phase-1 I fire the clay on the shelf for 10 minutes at 1000˚F (538˚C) and then complete the recommended phase-2 procedure?
    Answer: It sinters fully and is strong enough to be domed.

  6. What happens if I place a disc inside a screen under activated carbon and fire it at 1500˚F (815C˚) for 1 hour? Will the air inside the screen area be enough to allow it to sinter? (See Photo #2.)
    Answer: No, it doesn't sinter (see Photo #3 )

    Photo # 2

    Photo # 3

  7. If I am attaching two fired pieces together using oil slip can I bypass phase-1? If so, at what point does it not sinter?
    : It doesn’t sinter when fired at 1500˚F (815C˚) for 30 minutes. I fired three pieces separately and then used sterling silver oil slip putting them together. Additionally, I added syringe clay as a decoration and as reinforcement where the bail and the base connect. At first it looked like it sintered, the new clay shined up, but when I applied force it all fell apart. (see Photo # 4.) I then re-applied more oil slip and syringe clay, and fired it to the Mitsubishi’s recommended firing with phase-2 holding for 2 hours. It fired perfectly and doesn’t come apart with applied force. I will need to test this again with firing the piece for a longer time.
  8. Photo #4

    If you are working on a prize pieced, take the time and complete it using Mitsubishi’s recommended firing. If you are willing to cut some corners and time, then try some of the above tests. I wanted to make sure the tests were repeatable so I re-tested the pre-firing using the torch and made this pendant from test disc #4 and oval #3. It seems to be working. I can say that in a classroom situation, where time is short, I may use the quick firing using a torch for phase-1 as long as the work is not very large and complicated. I don’t want to risk harming someone else’s piece of art! I will also be sure that students know the recommended firing schedule and the benefits of sticking to it.

    I will continue testing multiple firing to see if longer firing allows the two fired pieces to adhere together without using phase-1 firing.

Tuesday, March 27, 2012

Know Your Stuff

by Linda Kline
Director of Education

It’s hard to believe that just 16 years ago Precious Metal Clay made its debut in the United States. Since then we’ve gone through three generations of PMC fine silver – Standard, Plus, and PMC 3 – plus PMC Gold, and Aura 22. Now we have PMC Pro and the new kid on the block, PMC Sterling. As if that wasn’t enough, several types of copper, bronze, and other interesting base metals have joined the mix. It’s absolutely mind-blowing.

Above: "Faux Jasper 2" by Hadar Jacobson using just a few of the newest metal clays: copper, bronze, white bronze, and pearl grey steel.

The other thing that is really mind blowing is that each one of these formulas has its own unique set of firing standards. It was confusing enough when we just had to keep track of the nuances and variables associated with firing fine silver. Now we have different firing schedules, temperatures, chambers, and carbons mixes to go along with each of the various products. Whew!

If you plan to teach with some of these new materials, know your stuff! There is nothing worse than trying to wing it in the classroom. Sure, things naturally can and do go wrong. But make sure you’ve practiced extensively with whatever type of metal clay you plan to teach with. Have plenty of samples on hand to share with your students, including your mistakes. There is plenty of value in making mistakes and we’ve all made them. Fess up to your blunders. Through are, “Oh crap!” experiences we gain lots of, “Ah ha,” moments and plenty of valuable insight.

No one can remember all the firing schedules associated with the wide variety of products now on the market. Start a firing journal to record your experiences, successes, and mishaps with each of the metals. Note the times and temperatures, the type of carbon used, and any little nuances and nuggets of wisdom. Turn this into a quick reference guide – a cheat sheet – and share it with your students. One of the biggest parts of being a successful teacher is in paying your dues….and paying it forward.

Creative Blessings,

Saturday, March 24, 2012

Movin’ On Up

by Jennifer Roberts

I spent a few days this week helping a friend who got into a jam when he moved from one rented commercial space to another. This friend is not a metal clay artisan. He's an artist of a different sort, dealing in bicycles, community events, and community art. He moved out of his last location and heard absolutely no complaints from his former landlord about anything, including a mural placed on the building by agreement as part of a large-scale revitalization project. He heard nothing, that is, until he was served with a lawsuit.

I’ve assisted many artists over the years with their legal woes and this situation is far and away the most common. Two things tend to get in the way of making sure the exit from a former studio or storefront is hassle-free. First, the old space is not the new space. It’s not the exciting prospect of more room or a better location or a shiny new place to live and work. Dealing with the details of leaving isn’t exactly fun. Second, if you aren’t leaving the space exactly as you found it, there may be an element of fear. It’s kind of like not wanting to look at your thumb after you just smashed it to smithereens with a hammer. But like so many things, dealing with a problem up front usually gets far better results.

So, here are some things to remember when you move out of your current space and into the new digs:

1) You have the power of documentation. Clean it up, fix it up, and take date/time stamped pictures. If possible, do a walk-through with your landlord before you leave. Even better, film that walk-thorough.

2) There are likely protections in your lease. It’s a rare lease that doesn’t provide some mechanism by which each party must let the other know of a problem before they can be held accountable for it. This must usually be done in writing and you almost always have time to fix the problem. These sorts of provisions come into play most often in the case of alterations, such as moving a wall, venting your kiln, or putting up a sign. These notice procedures prevent your landlord from saying nothing and then suing later you when you are no longer capable of doing any work on the space yourself.

3) There may be protections in state or local law. In Texas, commercial landlords must return security deposits within 60 days and/or provide a written statement explaining how much was withheld and why. Failure to do so can leave the landlord liable for damages of more than three times the security deposit, plus your attorney’s fees. It may also cause the landlord to lose the ability to sue for “damage” to a space (in our case a mural lately described as "graffiti.") You landlord may be able to withhold some or all of your deposit, but he or she most likely has to tell you why. In writing and on time. Or else.

Thinking about these things before you vacate your old space can be the difference between spending your valuable time and energy on a lawsuit or devoting it to your next beautiful creation.

Disclaimer: The materials available on this blog are for informational purposes only and not for the purpose of providing legal advice. You should contact your attorney to obtain advice with respect to any particular issue or problem. Use of this blog or any of the e-mail links within does not create an attorney-client relationship of any kind.

Friday, March 16, 2012

More Tips and Tricks from Janet Alexander

by Janet Alexander
Technical Advisor

Cutting Wire

They say flush cutters give a flat cut on wire, but to me it's still at an angle. Sometimes it's important to have a flat end on a wire. Here is what I do. I easily file wire ends flat without bending the wire by placing the wire inside flat-nose pliers with just the tip hanging out the other side. This holds the wire while filing.

Alternatively, I can place the wire into the point of the “V” shape in the bench pin with the end pointing upward. This holds the wire so it can be filed flat.

If you’d like to saw the wire instead of cutting it with pliers, make a channel across the top of the bench pin using a wood saw.

Now place the wire into the channel hanging it out the distance needed and saw it off against the side of the bench pin.

Polishing Strategy

When I am working on a polished piece and I don't want to scratch it while I continue to polish, I place it on leather. The leather keeps it from sliding and getting scratched.

Tuesday, March 13, 2012

Artist’s Journal: Studies of Antiquities

by Lois Lynn
Guest Blogger

Exploring the Designs and Techniques of Ancient Metal Artisans with a Modern Twist

This month, I tried my hand at replicating an ancient design. I’ve been looking through classical jewelry books and wanted to create a ring inspired by those elements. I wanted my piece to have an air of being created in antiquity, one in which you could see the organic markings of the artisan as the ring was formed and fashioned.

I also wanted to experiment with a purchased, open-back, fine silver, bezel cup to see how it would respond with PMC3 to blend the ancient with the modern. Because metal clay shrinks about 15% when fired, the challenge here would be how successfully the pre-made bezel would survive structurally when the clay surrounding it shrank.

I started with seven grams of PMC3 and divided it into two parts, putting one back into the protective pouch. I wear a size 7 and this ring was going to be rather wide so I went up three sizes to size 10. Slipping a ring gauge on a wooden ring mandrel, I noted where size 10 fell, taped a piece of parchment paper in place, and marked it so I could position the clay in exactly the right place. I then spread badger balm on the paper and some on the tapered end of the wooden mandrel so that the whole unit could slide off the tool without catching.

Using my hands, I rolled out a thin 5” x 1/8” snake of PMC3. I cut the snake in half and created a double ring shank, which I mounted on the mandrel. I positioned the commercial bezel cup between the two snakes and wrapped the ends on either side of the bezel so that I knew exactly how long each snake needed to be. I then cut the snakes on the diagonal on either side of the bezel and pasted them down.

Then I wanted to add an additional decorative section on each side of the bezel, so I took the remaining PMC3 from the package and formed another snake, which I used to create a number of coiled elements. I initially rolled a long snake to assure that all of the elements would be the same size. I put oil slip on the shank where I would be mounting the first coil detail, pressed it onto the shank, cut it to size with an exact-o knife and re-formed the ends so they joined the edge of the shank smoothly. I did the same with the second coil on both sides.

I wanted the last coil to end in a curled half circle so I applied oil paste carefully to the shank, took the tapered end and applied it to the shank in a “c” curve. Cutting off the excess at the shank, I again refined the end and made sure all the bands were well secured. I applied the “c-shaped band to the other side, making sure the c's were the same shape and size.

I then embellished the ring. Granulation was very popular in ancient times so I added small, fine silver balls to the shank. I pasted one in the inside of the “c” and then repeated it on the other side, checking the symmetry with the first side. Then I added three more balls to both sides and bottom of the shank, each one slightly smaller than the first. A small detail that some may think unnecessary, but one I would enjoy seeing when I wear the ring… a little secret surprise for me!

I refined the inside of the shank and all the embellishments on the ring. Because I was working in such a small space, I wet my finger with saliva (Linda, my instructor’s discovery!) to remove unwanted marks and give the embellishments a smooth, polished look. When applying granulation in the past, I found that I needed to carefully wipe away any clay that obscured the balls and make sure their surfaces looked shiny all the way around. Otherwise they never take on that look of ancient Etruscan granulation.

(Editors note: I use saliva for wet sanding in my work too. It gives a different look than water applied with a brush, but you should be careful to wipe excess clay on a towel before "re-wetting" your finger.)

I have been dreaming of and sketching ancient ring designs for about eight months so I was very excited to see how the ring would come out! I set up the firing sequence and fired at 1650ºF for two hours. I was so excited to see the fired ring, but when I opened the kiln I realized I fired the kiln without the ring in it! Humm…. So I set up the firing schedule again with the ring in the kiln and waited another two long hours to see the result. It looked beautiful!

I carefully brushed the ring and tumbled it for eight hours (editors note: tumbling silver metal clay for an extended time will wear away fine textural detail, so use that technique with discretion.) When I opened the tumbler, I could hardly contain myself. Wow, it looked great! I antiqued the ring with liver of sulfur and mounted the cabochon garnet in the commercial bezel cup. I ran a risk by using a commercial finding, but it didn’t seem to compromise the look of authenticity of the ring, as it was not that prominent. And doing so allowed me to experiment with blending ancient with modern techniques.

The ring looks exactly as I designed it. I could not be more pleased!

Friday, March 9, 2012

PMC Sterling: Let the Testing Begin!

by Jennifer Roberts

Last month, we hosted our first PMC Sterling class, taught by Janet Alexander. At left, you can see some of her students hard at work.

As with any new material, the possibilities are endless and every answer seems to lead to a new question. This can be exciting, but it can also be expensive when you find out something didn't work as you expected.

So, for the next six months, Janet will be asking and answering some of those questions for you. She'll wonder "what if," test, and post her results. From firing to finishing, and everything in between, she'll take the guesswork out of this new materiel for you.

Janet's first PMC Sterling Silver post is set for the end of the month.

Monday, March 5, 2012

Playtime Inspiration

Posted by Lora Hart
Artistic Advisor

As one of the jurors for Metal Clay Artist Magazine's 2012 challenge, I'm really excited to see what wonderful work everyone has produced using "Metal Clay Plus". The theme of the contest was to use our favorite clay and any other inclusion, material, or add-on. That's it. Such a wealth of material to choose from. Did any of you enter? If not, what material(s) might you have used if you had?

Me playing with watercolor enamel.
One of the things that is most exciting to me as a maker is pushing my own boundaries, trying something new and incorporating that technique into my work. I just got back from a week long play-date in Texas with two of my very good friends (I live in California). There I learned how to torch enamel, use watercolor enamel (so fun), make and sew together a handmade journal, and experimented a bit with Creative Paper Clay. I already have some new ideas swimming around in my head. Next year the play-date is already scheduled to be held at my house!

Almost done. A little more color I think.
A play-date should be just what it sounds like. A day filled with play and experimentation. Mothers have no problem scheduling one for their kids, why shouldn't adults benefit from the camaraderie and imaginative input from their friends too?

If you'd like to try your hand(s) at hosting a friendly fun day, here are a few ideas to get you started:
1. Get together with one or two friends, leave the metal clay in your tool box, and share some hobbies that might be new to the others.
2. Take a trip to the craft store and fill your baskets with anything that looks interesting, then take it all home and "Make it Work".
3. Visit a couple of jewelry galleries to find artist's you may not be familiar with. Have a discussion about what you do or don't like about their work, style, materials, or theme.
I'd never tried making a book before.
4. Go to a bookstore, grab a table to spread out on, and gather coffee table books on anything but jewelry making. What techniques can you borrow from woodworking, ceramics, art journaling, or book making?
5. Sit around the dining room table with pads of paper; watercolors; brushes; paper; crayons; pencils; pastels; or any other art supply you have in the house - and just draw 'till your heart's content. Doodle. Make marks. Grafitti. Zentangle. Don't have a preconceived idea of the outcome. Nothing has to be symmetrical, professional looking, or even recognizable.

No idea what that birdie figure is.
Artistic friends are valuable sources of support, inspiration, and camaraderie. And best of all you don't have to travel to learn from them, pay for anything but materials (and sometimes not even that), and you can make your own 'class' schedule. Why don't you schedule a date with your besties right now? Carry on!

All photos courtesy Vickie Hallmark

Thursday, March 1, 2012

Janet's Tips & Tricks

by Janet Alexander
Technical Advisor

Straightening Wire

Have you ever had a small piece of wire you wanted to use but it was all bent out of shape?

Bend it as straight as you can using flat-nose pliers.

Place the wire on a smooth anvil or steel block with another anvil or smooth steel block over the wire. Slide the top block back and forth across the bottom one keeping the wire between the blocks.

The wire rolls along straightening out as it rolls!

This is also a great way to work-harden the wire.

Placing Tiny Stones

Have you had a hard time picking up tiny stones while placing them into a setting? Roll some bee’s wax between your fingers into a point. Now use the point to pick up the small stone.

To remove the stone from the wax, place it into the setting and roll the tip of the wax away from the stone.

To clean the wax off the stone wipe it with a towel after setting it. If you plan to fire the stone in place, the wax burns off cleanly in the kiln.

Keep the comments and questions coming!