Tuesday, October 30, 2012

Failure is a Chance for Learning

by Janet Alexander
Technical Advisor

I read somewhere or was told that painting the stainless steel container used for firing the sterling silver clay would keep it from flaking, so I set out to test the idea.

I took a brand new clean stainless steel container and lid and painted them with high-heat paint used for coating rifle barrels. After it dried, I baked it at 300 degrees F for several hours to cure the paint.

Unpainted Container

Painted Container

Next, the test to see if it flaked or not.

I fired it at 1500 degrees for 30 minutes with coconut carbon and some sterling silver rings inside. I removed it from the kiln while it was still hot. For the first minute or two nothing happened. But then all of the sudden paint started flying off across the lid like stacked dominoes falling over. It was very interesting to watch the paint flake off in a line going around the lid. Then as the bottom started cooling the paint on each corner flaked off. Watching this, I decided that the reason the paint flaked is because the metal was contracting while cooling, forcing the paint off the surface. There was less metal flaking, but as I used the container over and over again the metal started flaking also.

So, back to square one. But I do know now that paint doesn't work. A friend told me to try coating it with kiln wash. Maybe I will try that next?

More sterling sliver clay is on he way for my testing, so keep an eye out for the November test and have fun claying around!

Friday, October 19, 2012

Vibratory Tumblers

by Janet Alexander
Technical Advisor

How is the Tumble-Vibe different from a rotary tumbler?

The basic difference between a vibratory and a rotary tumbler is the way the unit is driven.  A rotary tumbler consists of a barrel that sits on rollers causing the barrel to spin. Polishing media and the objects to be polished (jewelry pieces) are placed inside the barrel. As the barrel spins, the contents fall and slide over each other causing abrasion or polishing to the jewelry pieces located in the top 1-inch of the sliding media.  Jewelry pieces not located in the top inch are not polished. Some items can become dented due to the polishing media falling on the jewelry pieces.  It can take hours, days or weeks to bring a piece of jewelry up to a high shine using this type of unit. The lid on the barrel can leak or come off during the process.
A vibrating tumbler includes a bowl that sits on an out-of- balanced motor. As the motor moves, it causes the bowl to vibrate in all directions. The polishing media and jewelry pieces are placed inside the bowl. The bowl’s vibration causes the objects in the bowl to rotate around the bowl in two directions rubbing and polishing the jewelry 100% of the time. The items are polished much faster than a rotary tumbler and there is no chance of leaks, spillage, or denting of pieces. The items can be easily retrieved by opening the lid and fishing through the polishing media.

 A variety of different media, from cutting, to polishing, can be used in the vibratory tumbler including ceramic and plastic abrasives, walnut shells, and steel shot, making the vibrating tumbler more versatile than a rotary tumbler. The ceramic and plastic abrasives are sold in different grits. Polish is embedded in the walnut shell with the same polish jewelers use on buffing wheels. Steel shot, due to its hardness, is used as a burnisher. As it moves across the jewelry it rubs and burnishes the outer layer of the metal. 

General Instructions for the Raytech TV-5 Model
  • The working capacity* of the Tumble-Vibe 5 is approximately .05 cu. ft. (three pints) or 4 pounds. The capacity includes the media, water and the work pieces.
  • If the tumbler will be used for polishing as well as for cutting, always reserve one bowl strictly for the polishing media so it can remain free from embedded cutting grit.
  • Successful finishing of most jewelry requires preparing the jewelry. Parts must be filed, sanded, or ground smooth over rough areas. Attempting to finish jewelry parts without adequate preparatory finishing can result in very long finishing cycles and loss of detail in the jewelry pieces.
  • All plastic media or ceramic media should be broken-in before using. Media that is not broken-in may cause scratches. (See separate section, below, for breaking-in plastic media.)
  • Keep a 70% media to 30% jewelry ratio. Too many items tumbling at one time can produce a poor finish.
  • Always use cutting/burnishing soap with the media as required.
  • If using steel shot, fill the bowl with water so that it just covers the top of the shot. Never completely fill the bowl with water. Too much water or soap hampers the media’s action. After tumbling, remove and dry shot.
  • If using plastic or ceramic media, add 1 ½ oz. of water and a ½ teaspoon of polishing compound. Note: if the machine does not roll the media well at the start of a cycle, there is too much water or soap.
  • Change water if it becomes gray or loses its suds. Rinse the bowl and clean the media.
  • If the media tumbles too long without replacing the water, the jewelry pieces will absorb the gray sludge which is very hard to remove. The manufacturer recommends changing the water every three hours.
  • When using ceramic media, don’t allow the bowl to run dry. This will cause premature wear on the bowl.
  • Walnut or other shell media do not require water. Fill the bowl ¼” below the center cone and jewelry items.
  • On average, dry polishing media is good for polishing up to 200 hours of use. When not in use, store in an air-tight container. See manufacturer’s instructions.
  • Do not use media filled with silicon carbide or alumina powders as this will impinge and impregnated the metal surface and retard polishing.

Breaking-in Plastic/Ceramic Media
1.   Place media into tumbler bowl.
2.   Add water and polishing compound /soap.
3.   Tumble without jewelry for one to two hours.
4.   Rinse media and bowl. Rinsing the media in a colander works well.

Monday, October 15, 2012

Pretty Is As Pretty Does

Posted by Lora Hart
Artistic Advisor

When I made the move to Richmond, I decided that I wanted my studio separate from my home. There were too many distractions in my apartment studiolo in Venice (couch, dishes, cats) and I knew I hadn't been as productive as I would have liked to be. I rented a great 161 sq. ft. place in an artist's co-op about 10 minutes away, and I have to say I'm really enjoying the drive and the hustle and bustle of the facility. After unpacking all the boxes (who knew I could squeeze so much into my old, tiny, studio?) I started going through photos on Flickr and Pinterest of other people's work spaces so I could get some new ideas on how to set up mine.

Views of my new, unfinished, studio at ArtWorks Virginia. 

The results I got were so interesting. Some studios looked like they were ready for a magazine shoot, and others looked like the artist was working furiously just moments before the shutter clicked. I've read posts online of folks who think they have to clean up before (or after) each creative session. I know jewelers whose benches look like a hurricane just hit (but they know where to lay their hands for each tool or supply needed).

I think I'm somewhere in between. My last apartment was a single. One room. Living, sleeping, dining, entertaining, and working - all in one space. So of course I wanted to keep the studio area neat and clean. I know I do more creative work when I start with a neat bench top, but the floor and surfaces were always a mess. My new studio has a big glass window that let's passers-by take a peak at my process. I don't want to appear slovenly, so my instinct is to keep it in tip, top, shape. But my natural working habits don't mesh with the concept of a tidy space.

Where do you fall on the photo-ready or well-used look of your work space? Do you care what others think when they view it, or is your motivation based on your working methodology? 

Friday, October 12, 2012

It's All in How You See It

[Editor's note: We love Lora Hart's eye candy series. Check out today's eye candy, below, and visit her blog every week for more.]

It's that time of year again. Now that I'm in the east, I can actually see the leaves change. There were a few trees in LA that developed some color, but nothing like I'm expecting this year.

One of the greatest things about artists is how they each interpret a theme differently. All leaves, All unique. Here are examples of chasing and repousé, forging, carving, slip painting, piercing, soldering, and gluing; using steel wire, silver wire, resin, natural leaves, wood, sterling, metal clay, gold, and iron. Styles are simple, complicated, modern, gothic, realistic, and interpretive. And all are beautiful.

Tuesday, October 9, 2012

Think Quick!

by Linda Kline
Director of Education

The staff at PMC Connection tells me there is one question that is most frequently asked by teachers:  “How much silver should I buy to be ready for my class?”

It doesn’t matter how long I’ve been teaching, that’s a dilemma that presents itself at the start of every class. 
In “season,” November-April, I have weekly classes at Vero Beach Museum of Art…….IF the classes have enough registrants to make.  Unfortunately, I don’t know if that will happen until a few days before the start of the class. That leaves little or no time to order adequate tools and silver in time for the launch of the class. 

In the good old days when silver was $17-25 a gram, I could afford to order excess and keep a generous inventory. But the extreme rise in prices and shipping costs has put the kibosh on that luxury. These days, I eek through by estimating what I think I’ll need.  But it’s frustrating and causes a lot of stress and financial strain. I can’t afford to order too much and sit on the inventory.  Neither can I afford to run out of silver for my students.

If I’m low on silver or caught short-handed waiting on an order to arrive, I’ve got a few fallback projects that I can pull out of my little bag of tricks. PMC Sheet and fine silver wire are really good resources to have on hand and can be used in many different ways. You can twist some fine silver wire, for example, cover with multiple layers of PMC3 Paste, add some bling, fire, and you’ve got some pretty spectacular earrings. Or dazzle them with PMC Sheet. It’s less expensive than clay, and has unlimited creative options. Try some abstract folded or origami designs for terrific earrings. Or, cut out some paper punched elements and add them to fine silver wire to make some affordable, lightweight earrings. A change in materials can be a wonderful tool for helping students break out of a design rutt.

In short, if you have unlimited financial resources or you’re psychic, you have it made.  If you’re like most teachers, however, the best we can do is what we do best: wing it……with panache, of course. Think head and always keep some materials at the ready that you can use to challenge students when your best laid plans leave you temporarily short of metal clay.

 Somehow it always seems to work out okay……

Friday, October 5, 2012

Testing Your Kiln's Temperature

by Janet Alexander
Technical Advisor

 Now that most kilns have a computerized controller it’s become easier to control the kiln’s temperature. But, is the controller’s readout accurate? With so many varieties of bronze, copper, and silver metal clays, it has become important to know if your kiln’s temperature reading is correct. Otherwise, you may have problems with the clay not sintering correctly or getting too hot and melting. Additionally, the kiln should be tested for hot spots and cooler spots. Every kiln is different.

Testing can be done by using a pyrometer (which is how I used to adjust my kiln’s temperature before there were controllers) or by using kiln pyrometric cones. The pyrometric cones are supposed to bend when heated to a specific temperature for a certain amount of time. That means that pyrometric cones give a temperature equivalent; they are not simple temperature-measuring devices. According to a pyrometric cone manufacturer, cones have over 20 variables that can affect the cone’s bending, including the cone's composition, particle size of raw materials, type of forming process, moisture during forming, density of the cone, geometry of the cone, setting height, and angle and the heating rate. Atmosphere also affects bending behavior. Wow, that’s a lot of variables!  So, let’s look at testing with a pyrometer or a kiln test kit.

I used the kiln test kit sold by the PMC Connection. According to experts, the average kiln controller is accurate to ±10°F (±5.5°C) so keep this in mind while testing. Additionally, run the test several times but move the thermocouple to different areas of your kiln. Place it towards the back, near the front, off to each side, and etc. Test at different temperatures. I conducted tests at 1110˚F, 1200˚F, 1290˚F, 1470˚F, 1560˚F, and 1650˚F. I found that both readouts were within a few degrees of each other until the temperature got up to 1650˚F. Then they were off by 10˚F! So, I added another thermocouple from my casting kiln.  All three read different degrees but were within the accuracy range.

Now I know why my PMC3 clay had a crystalline look to it when I fired it at 1650˚F; it was getting too hot! So, now I lower the temperature of my kiln by a few degrees when setting it at 1650˚F.

The Test Kit Includes:
  • Sensor  reader (tester)
  • 9V Battery 
  • K-type thermocouple TP-02A  
  • K-type thermocouple TP-03 
  • Case 
Use the TP-02A thermocouple (larger one) for testing your kiln. It has a temperature measuring range of (-58˚F to 1650˚F).

The Steps

1.  Install the 9 V battery into the unit’s back.

2.  Insert the plug into the bottom of the sensor reader making sure the plug’s polarity matches with the sensor’s polarity. 

3.  Insert the thermocouple into the kiln.

Caution: Don’t insert it past larger ceramic end or the wires will burn!

4.  Place the thermocouple near the kiln’s thermocouple for the first run of testing.

5.  Turn on the kiln and set it to hold at the test temperature for at least 15 minutes.

The sensor reader can read in Fahrenheit (F) or Centigrade (C). Turn it on by sliding the button from the center (off position) to the F (if measuring in Fahrenheit).

6.  The sensor displays its reading. Allow it a minute to stabilize to the temperature. Test at various temperatures. I found that my kiln was accurate until it reached over 1350 (F).

7.  When finished testing, turn off kiln and sensor reader and allow the thermocouple to cool before touching it.

Monday, October 1, 2012

Seen / Unseen

Posted by Lora Hart
Artistic Advisor

Hear ye, hear ye! Get thee over to Crafthouse immediately for some amazing inspiration! Metal clay artist, Lorena Angulo, has curated an amazing exhibition called Behind the Brooch which focuses on the hidden side of jewelry.

Lorena Angulo. 'Corliss Calivera'. Bronze, Copper and Silver metal clay.
In all of my classes I try to inspire my students to take as much care with the back of their pieces as they do with the front. Make sure the reverse is beautifully finished, add embellishments, perhaps set a stone. Give the wearer a reason to make your work the first thing they grab out of their jewelry box in the morning. Every element of design adds another layer of delight, intrigue or introspection. Each detail makes the work more complete and, dare I say, artistic.

This exhibition brings together artists from around the world, sharing their visions, their ingenuity, and their unique voices. A wonderful opportunity for exploration from the comfort of your own home. I was also very interested to read their statements regarding the work. All of the statements were short (around 50 words), and were not only informative, but reading their views or about their process added so much more to my understanding of their work.

(Edit) Lorena put together an inspiring and cohesive collection and I'd like to thank her for the inspiration.