In this tutorial, Lena Marie Echelle will show you the method and tricks she uses for making a simple locket hinge out of sterling silver.
Here is a list of the tools you'll see in use:
Jeweler's saw and fine blades
Needle files (triangular, round, flat)
Awl or scribe
Calipers or dividers
Tube cutting jig
Propane torch and solder
I have already fabricated a sterling silver bezel mount for a domed, heart shaped enameled piece of copper; the back is a slightly domed sterling silver piece with the same profile as the front. All work on the locket besides riveting the hinge pin is done prior to setting the enameled piece, but the fit for the bezel needs to be close from the beginning. Here, I am checking the fit one last time before starting to work on the hinge.
If you want to be able to catch a photo in the locket, it is useful to have a strip around the inside. For my locket, this strip also functions as the back of the bezel for the enameled heart, and it gives strength and thickness to both sides.
Before starting to construct the hinge, make sure both sides match up evenly, all the way around. Pick a flat part of the piece for the hinge. Make sure the placement of the hinge will complement the design of the piece, and keep in mind that the clasp for the locket usually goes opposite the hinge. Once you have located the where the hinge will be placed, start to file a groove for the hinge using a triangular file.
The tubing I am planning to use is purchased, but you can also make your own. Either way, the walls should be at least 24 gauge, and, if silver, no smaller than an 18 gauge wire should be used as the hinge pin. The hinge pin should fit snugly in the tube to avoid wiggle in the hinge.
After the groove has been well established with the triangular file (the cut should be no wider than the tube you are planning on using for the hinge) switch to a round needle file in order to match the shape of the tube. Once the groove is deep enough for the tube to rest securely (the depth of the groove should be nearly half as deep as the outer diameter of the tube in order to make sufficient contact with each side of the locket), measure the approximate length of the groove. Divide this number by the number of knuckles you will use in order to establish the length of each knuckle. I cut these a little long; the outside knuckles can be filed down to size if they stick out a little. My smallest hinges are about 6mm long, enough for three knuckles of 2mm each. This hinge will be about 9mm long.
It’s easier to cut a straight line on tubing if you use a tube cutting jig. Most jigs also have a stop which makes it easy to cut equal lengths. I drilled a hole in my bench pin that the handle of the tube cutting jig fits into. This way both hands are free for holding and cutting. It is very important that the edges of the tubes be cut absolutely square.
Use your fingernails or a light touch with a file to knock off any burs on the edge of the tube after cutting. Line the knuckles up to make sure they are cut straight, and compare them to the groove in the piece.
Paint both locket halves with yellow ochre or other solder stop. Note that I haven’t even cleaned the metal of the locket since soldering the inner strip to each half. Since the metal where the tubing will be soldered is clean from filing, having the rest of the piece oxidized and dirty actually helps to keep the solder from running where you don’t want it. Just make sure the tubing and solder are clean, and don’t paint solder stop on any part of the filed groove.
Secure both halves together with iron wire, lock tweezers, or a third hand, and flux the groove.
Using an atmospheric air and propane torch, I start to gently heat the piece. Meanwhile, I place the fluxed hinge sections into the groove using tweezers and my soldering pick. I push them together and make sure they are straight. It is critical that the knuckles are aligned properly at this stage.
Before soldering, I turn off the torch and inspect the piece from every angle to make sure the knuckles are in place correctly and that the locket halves haven’t moved, and I cut three tiny pieces of solder. It’s important to cut very small pieces so that solder doesn’t flow where you don’t want it. You can always add solder later.
Place two of the solder pieces, one on each of the two knuckles that are attached to the back of the locket. Start to heat, and use a solder pick to tap the solder or the knuckles into place if they try to move when heat is applied.
Before soldering the middle knuckle to the other side, quench the piece and make sure that the two knuckles on this side are soldered properly. If the middle joint accidentally got soldered to the back side, reheat the piece gently and use tweezers to lift it off carefully when the solder flows. Saw off a length for a new middle knuckle if the original gets marked or deformed while removing it. Once everything is ready, paint the groove between the two soldered knuckles with solder stop (yellow ochre) and rebind the two locket halves. Flux the front side, set the middle knuckle in place, solder with remaining tiny piece of solder.
Pickle the piece, and try out a hinge pin. Before permanently placing the hinge pin, remember to do any final soldering on the piece. This is the time to make the clasp for the piece, as well as solder on a bail from which to hang the locket if you haven't yet done so. In the case of my locket, I also need to set the enamel heart before I can rivet the hinge pin.
Inspect the piece closely to make sure that all three knuckles are firmly soldered. You can file the ends of the hinge to flatter your design.
If you want the pin to be flush with the outside of the hinge, widen the ends of the hinge. You can use a file or an awl. Either way, the goal is not to remove metal, but to widen the outer edge by twirling the tool.
I like to draw down wire until it is just the right size to fit into the hinge. You can also file down a wire that is a little too big. Once it is the right size, insert the wire and saw off. I like to saw the wire while it is in the hinge. I use a light touch and don't saw all the way through (to avoid marring the locket). Instead, I break the wire off with my hands.
Using a triangular file, I cut a small groove in each end of the wire. This will be where the wire expands during riveting. It will also make the ends of the wire look like little screw heads.
To rivet, I use a light touch with a small hammer. The hinge is complete!