Alice Alper-Rein        JEWELRY BY Y2A, Ltd.
Fine Contemporary Art Jewelry in Silver and Gold
            

PMC TIPS, TRICKS AND TECHNIQUES FOR: 
Hinges anD Cold Connections
By: Alice Alper-Rein

Hinges

Here are some tips for creating hinges so that you can create a bracelet or pendant or a working MC locket, book or box that opens and closes. It’s best to use PMC3 for strength when creating hinges using the tips below.

A. THE HINGE TUBE


   1.  Metal Clay Tube Hinge 

STEP 1:  First you'll need to create a tube out of MC: Make a slit in a straw from end to end and oil it. Roll out MC lump clay to a 2-card thickness and wrap it around the straw. Cut away the excess clay and secure the join with MC slip. When the tube is dry (leather hard), compress the straw and slide it out of the MC tube. NOTE: A MC tube can also be made using an extruder fitted with a hollow core insert. MC tubes can also be made by drilling through the center of MC rods.  Two ways to create MC rods: roll a thick snake or force lump clay inside an appropriate size straw. When the clay has dried, cut away the straw and use a drill to create a tube.

STEP 2:  Using a single edge razor blade, cut the leather hard tube into 3 segments (also called knuckles.)  The knuckles can be equal in size, but they don't have to be. I like to make the two outer knuckles the same size and the middle one slightly larger. The important thing is that they all fit back together perfectly.

STEP 3:  Place fine grit sandpaper on a level table and sand the knuckles edges slightly.

STEP 4:   Fit the knuckles back together on a toothpick sized dowel or piece of wire. Using MC slip, join the 2 outer segments to one part of your design and the middle segment to the other design element. You might have to notch out a bit of MC with a small round file to fit the knuckles into place to insure good surface contact.

STEP 5:  Dry the attached hinge tube sections and remove the toothpick or wire and fire your creation on a support material like vermiculite or fiber blanket. A fire in-place support might be necessary to prevent the knuckles from collapsing when using Standard PMC or PMC+, but it is not necessary when using PMC3. Use a paper lollipop stick, a toothpick or paper q-tip (cut the cotton ends off) for a burn away, fire-in-place armature, if necessary.


STEP 6:  After brushing and tumbling, fashion a hinge pin. See Section B: The Hinge Pin, below.

   2. Fine Silver or Sterling Tubing  

Follow the steps in Tip # 1, substituting fine silver or sterling silver tubing for the MC tubing. Use a jeweler’s saw to cut the tubing into sections.  An adjustable tube cutting jig is a handy gadget to have for this task. Use it to measure, hold and align the tubing as you cut it to insure uniform cuts. Consider that the milled tubing won’t shrink during firing but the MC parts of the project will shrink. This will very likely cause the project to warp. Compensate for this by using an un-tapered, half round file to create a well for the tube hinge to sit in. Also, measure the FS or SS tube sections to be slightly smaller than the unfired MC structure. If you chose to SS tube, depletion gild the tubing (raise the fine silver to the surface by heating and pickling) to insure it will be bond to the MC.

   3. Syringe Coil Hinge Tube

Using no syringe tip inserted onto the end of MC syringe clay, extrude about 3 inches of clay. Coil this line of extruded clay by wrapping it around an oiled straw of the desired size. Balance the ends of the straw on cups to dry the coil without flattening it. When almost dry, slide the coil off the straw and use a scissors or tissue blade to cut the coil into hinge tube knuckles. Continue drying until the knuckles are leather hard. Syringe made coils won’t crack the way “snake” made coils often do. Use thick slip to attach the coiled knuckles to your project following the steps in Tip # 1. Coiled FS or SS wire can also be used to create a hinge knuckles. See Tip #2 for more about using FS or SS components with MC.

   4.  MC Sheet Hinge

Double the thickness of a PMC sheet by spritzing it with a fine mist of water and laminating it to itself for added strength and durability. Use this sheet to fashion a hinge tube by wrapping the PMC+ sheet clay around an oiled straw or toothpick. Secure it to itself using a glue stick. You can even make a tab for a sturdy way to attach it to your project when making hinges. Follow the steps in Tip # 1 to segment the tube into knuckles and to attach it to your project.


B.  THE HINGE PIN


Once the hinge tube has been fired to the project and the project has been polished, design a hinge pin to hold the components together and allow movement. Here are some ideas for creating hinge pins:

1.  RIVET Place a snug fitting wire through the hinge tube. The wire should extend the hinge tube slightly on both sides (1/16^thinch-1/8^th” inch.)  Against a steel bench block, use the chiseled face of a riveting hammer to splay (spreading out) one end of the wire. Then use the other end of the hammer to round out or flatten the wire. This will prevent the pin from slipping out of the hinge tube.

2. BALL THE WIRE Use a wire that fits snuggly inside the hinge tube. It should be cut approximately ¼” inch-1/2” inch longer than the hinge tube. Remove it from the tube and ball one end of the wire in the flame of a torch. Insert the wire into the hinge and ball the other end of the wire in the flame of a torch.

D.  REFERENCES: HINGES
If you’d like more detailed information on creating hinges, here are some excellent resources:

Lewton-Brain, Hinges and Hinge-Based Catches for Jewelers and Goldsmiths, Brain Press, Ltd, Calgary, Alberta,Canada 1997

McCreight, Tim, The Metalsmith’s Book of Boxes and Lockets, Hand Books Press, WI, USA, 1999

McCreight, Tim, The Complete Metalsmith, Brynmorgen Press, Portland, ME, USA 2004

Untracht, Oppi, Jewelry Concepts and Technology, Robert Hale, England-Doubleday , USA , 1882, 1985


Cold Connections

Cold connections are mechanical methods of joining parts together without using heat. Sometimes a cold connection is the only joining option because applying heat would damage or destroy components.

1. THE “G” WORD . Gluing is still considered to be a “non-traditional” way to attach one material to another. Some jewelers believe that the use of adhesives is a poor substitute for “proper” jewelry making techniques. Glues, adhesives and epoxies, also known as “chemical bonding materials,” play an important role in encasing and joining some modern jewelry materials, like polymer clay, plastics, paper and glass to metal. The key to creating long lasting connections using adhesives is to choose the proper one for the job. It is also essential to thoroughly clean all surfaces and to rough up each component, creating more surface area for glues to flow into. Visit http://www.thistothat.com  for suggestions about which glue to use for a specific task.

2. Rivets  There are many different kinds of rivets. Two common types are wire rivets and tube rivets. A metal wire or tube is placed through a hole that runs through all the layers to be joined. Once in place, both ends of the wire or tube are spread out and flattened to keep it locked in place.  The hinge pins discussed above, in the Hinge Tips section are rivets.
-It’s easiest to form a wire rivet when one end of wire is balled or flattened before it is inserted into the hole. Use a steel bench block under the work while hammering the other end of the wire.
-To make a successful rivet, use a wire gauge that fits snuggly in the hole
-Rivet the first hole and then drill each additional hole through the work to account for the slight shifting as the parts come together.
-Want a rivet that is flush with the work? Bevel the upper edge of hole and hammer the rivet flat into the bevel.
-Want movement in your piece? Use only one rivet. Cut a small slit out of in a thick piece of cardboard. Insert the cardboard spacer between the parts to be riveted. After flattening the ends of the wire, pull the cardboard out (soak it in water it if it’s too tight to remove easily)
- Use a colorful metal like copper or brass wire to create your rivet to add contrast and interest to your work.
-Use a tube to create a rivet in delicate materials. Anneal the tube, place it in the hole and flare out it’s ends. Place the bottom of the tube on a round punch and another round punch on the top of the tube. Flare the ends by tapping the punch with a hammer.

3. STAPLES 
-Drill two holes through the layers  and insert a “U” shaped piece of wire through the holes. Hammer the ends tight to the work.
-To set a stone using a staple or several staples, position the staples over the corners of the stone or across it’s mid section.

4. Tabs Picture a plus sign  +  Place your gemstone or found object in the intersection of the two lines and bend up the sides to hold the object in place.  That’s a tab setting.

-When making a tab setting out of metal clay, use PMC 3 and fire the piece for at least an hour at 1650°F for strength. Use smooth jaw pliers to gently bend the tabs over the stone.

-Consider using support materials when drying the MC work so that the tabs can be bent most of the way BEFORE firing

5. Prongs and Bezels   Prongs and bezels are really cold connections even though they might be applied to a piece during a kiln firing or by soldering them in place since setting the gem or stone into the prong or bezel is done by manually bending the prongs or smoothing the metal over the stone.

-If you must create prong settings out of MC, make them really thick to compensate for shrinkage during firing. Also consider strength issues, since MC/FS is really too soft for use as prongs.
-Consider embedding milled FS or SS wire into the MC structure to be used to create prongs
-Commercially made FS and SS prong settings can be incorporated into a metal clay piece


6. Wire Wrapping, KNOTING, Jump Rings AND head pins
-To begin a wire wrap, consider drilling a small hole in the fired MC piece in which to insert the starting end of the wire and then end the wrap by inserting the tail end of the wire through the same hole or through a second hole drilled somewhere else on the piece. File the ends to avoid having them catch on clothing or being uncomfortable for the wearer.
-Consider embedding the bent end of a length of wire in the structure of a MC piece before firing it. After firing, this wire can be used for decorative purposes, to add beads to or to wire wrap a stone or found object to the MC work.
-MC components can be joined to each other by drilling holes in each piece and connecting them with jump rings.
-Silk, leather cord, wool or chain can be used as decorative cold connections when threaded through holes in MC components, linking them together.
-Wire can be knotted. Start with a thin gauge of dead soft wire (it will work harden as it’s used) Check out this site to learn more about various decorative knots: http://www.animatedknots.com/

7. Tiny screws, bolts AND nuts  
-Substitute commercially available mini screws and bolts in place of rivets. Insert them through drilled holes, tighten the nuts and file away the excess.
- Some commercially available mini screws and bolts can be fired right into MC
-One benefit of using tiny screws to join parts is that they can be removed easily to rework the piece or to change out a photo, for example.

8. CLASPS are mechanical connectors and the component parts or housing can be made out of MC. Consider these: toggle clasps, barrel clasps including magnetic clasps, hook and eye clasps, box clasps and hinged clasps with friction pin.

REFERENCES: COLD CONNECTIONS
Lenart Kazmer, Susan, Making Connections, Disegno Productions, CA, USA 2008

McCreight, Tim, The Complete Metalsmith, Brynmorgen Press, Portland , ME , USA 2004