Hinges

Please see my video on the Basic Butt Hinge:  How To Make Hinges.

             

 Above, are two basic hinges that you are probably aware of.  The one on the left is a basic, odd knuckled butt hinge and the one on the right is an even knuckled butt hinge.

Hinges are everywhere. We take them for granted and are oblivious to the work that they perform.  That toilet seat would just be a board over a hole without the hinge, eyeglasses would not be too comfortable, and forget lifting that fork, covered with chocolate cake, to your mouth, without our knee, wrist, fingers and elbow hinges.   Jewelers can take advantage of the plethora of ideas that are all around us.  They are there for the borrowing – we just need to scale them down, tweek them a bit and solder the entire fabulous mess together.

         

There are tons of specialty hinges, like the ones for your laptop or a gate hinge.

There is a liftoff hinge (clasp idea, anyone?) and a quadrant hinge (whatever that is).

There are Hidden Hinges, Spring Hinges, Stand-off hinges, Ear Clip Hinges, you get my point, right?  They are everywhere and you can probably replicate them.  Hinge away!

Thoughts on Hinges

  • Don’t forget your safety equipment: eye protection, masks, gloves, body armor (?), whatever step you are on think:  Okay, what can hurt me in this process?  See my video: Jewelry Studio Safety and web page: Safety in the Small Jewelry Studio.
  • Making hinges requires the jeweler to measure properly, saw, cut, solder and file accurately.  Hinges are a great method for increasing your skill level and teaching the importance of accuracy.  Sloppy work, bad hinges.  Don’t be afraid.  Make a dozen of them, make more.  They are tough but, worth the effort.
  • Remember:  Hinges will only work if they are straight!
  • Things to consider:  What is the function of the hinge? How much weight will it bear?   In what direction will it open? How wide will it swing?
  • Factors affecting swing:  Thin metal and wide tubing = more movement.  Thick metal and narrow tubing = less movement.
  • If you have very thin metal, or are making a hinge for a round or oval container, consider making a bearing.  A bearing is basically a length of additional tubing that the hinge sits in.
  • Cutting a groove in your metal, for hinge placement,  is important because it helps to line up the knuckles when soldering and provides a stronger join by creating more surface area for the tube to be soldered onto.  In the illustration below, the top image has about a 1/4 of its surface area soldered to the metal.  The bottom illustration shows the metal without a groove.  The amount of tubing soldered to the metal is approximately, 1/16th.  Big difference, eh?

tube-fit

 

  • If you are making a hinge of copper, silver or high karat gold, understand that eventually, what started out as a tight fit, will start to loosen up.  Also, the process of soldering will anneal the tubing and it will therefore be more pliable and as such, more susceptible to loosening up.  So, have a tight fit between your tubing and your hinge pin.
  • Learn how to make your own tubing (another day, another video…)

Of course, you watched my video on Butt Hinges, right?  Good.  So, on to the making.

The Butt hinge allows a large amount of swing and is great for a hinged bracelet because of its flexibility.

Making the Butt Hinge

These are the basic instructions for the hinge covered in the video.

  • Size and pattern (if desired) two pieces of metal.
  • File a bevel on each side of the metal.  Be sure patterns, if any, are facing outwards. The bevels will angle downwards on the back side of the metal.
  • Alternately, if your metal is thick enough, just file a rounded groove, with the joint file (see below).  Don’t bother gluing the two pieces together or beveling them.

single-sheet-groove                                                    Single sheet

  • Using super glue (interesting article on super glues and Locktite by Johan Hugogård), line up the two halves – bevels facing each other. Don’t press the two halves together until they are in position. The bond will be immediate when pressed together. Clamp. Wait, 10-20 minutes.  Do something else for a while.  Examples: wash the dog, practice riveting, fix your hair, work on another project, hmmm…
  • Using the Joint File – These files come singly, also.  Just type in “joint file” at Otto Frei’s web site. (aka: Chenier File – see note below*), chainsaw file (see second note below)*, round needle file (rat tail shaped or graduated: not the best because it is not parallel) –  file a rounded groove where the two bevels meet.   When filing, think of filing in the center as this will help you to avoid over filing the ends.  You want an even, parallel channel to fit the tubing into. TIP: Try covering, the edge to be grooved, with Sharpie ink.  It will show how evenly you are filing.

*  I’d like to extend huge thanks to Charles Lewton-Brain for his help in deciphering the origin of the word “Chenier“.  Per Charles: “Chenier files is French goldsmiths jargon from a couple of hundred years ago, also German (as the French informed the Germans). Scharnier is the German word (derived from French).  Chenier means tube, and hinge.”

* Chainsaw files are probably best for thicker metal.  They come in 7 diameters (as far as I know): 5/32″, 11/64″, 3/16″, 13/64″, 7/32″, 1/4″, 5/16″.  Harbor Freight sells a set of three but, I don’t know the diameters, as they don’t state them on their website.

 

  • Check the fit, with the tubing – adjusting as necessary.  You want the tubing to sit well in the groove.

 

Turning Tubing into a Hinge

 

  • Draw a long line, down the entire side of the tubing with a thin line marker.  Use a cork backed ruler to lift the ruler off the bench and make this easier.  This line will be used for aligning our knuckles, later in the instructions.

line-ruler

 

  • Cut a hinge pin from either tubing or wire. Don’t forget that it should fit very snugly in the tube (telescoping).  Make the hinge pin at least 5mm longer than the tubing.

  • Now, we need to determine knuckle sizes. Ideally, there should be equal amounts of tubing soldered to each side. This distributes the stress evenly.  Here’s an example of how to find the length of your knuckles.  In this scenario, the area where I want to place the hinge is 16mm long.  To determine the length of the center knuckle,  I need to divide the total length of the metal in half: 16/2 = 8.  So, know I’ve got an 8mm  piece of tubing to be soldered on one side. Since I want an even distribution of stress, I’ll have to have 8mm of metal on the opposite side. I also need 2 knuckles – the two outer ones.  So, divide the 8mm in half again. Leaving us with two, 4mm outer knuckles. Our hinge might look like this, in formula:  4mm + 8mm + 4mm = 16mm – the total length of our metal. Got it?
  • Of course, you need to take into account your design and how the hinge will appear.  You might want to make evenly sized knuckles or another variation – consider how much stress the hinge will need to bear.  Are you making a box that will have a heavy lid and will be opened and closed often?  I’d go with a larger central hinge.  Is it a locket, with a thin metal cover, that won’t be opened often? Then even hinges will probably be fine.

hingespacing

 

  • Other  design considerations:  Try making the hinge from thicker tubing and using a smaller hinge pin or try a thinner tubing with a thicker hinge pin.  Making a prototype is a good way to test the functionality of your hinge.  It’s also good practice.
  • Using the above formula, mark where the central knuckle will be, on the interior groove of the two sheets of metal and down one side. You only need to mark the center knuckle!  I recommend using an Ultra-fine Sharpie for this as you want the thinnest line possible.  It is easier to measure accurately with a thin line. Ordinarily, I would recommend using a scribe (because of it’s semi-permanent nature and its fine line) but, as we are drawing the line down the face of the metal, I don’t recommend it – unless you don’t mind the scratches! While you are at it, mark the center line.  This is to help with the next step. Double check your measurements and make sure that they are as close to perfect as possible.

markknuckles

  • Marking the tubing. For this part, we are only concerned with the center knuckle. Since we are working with a piece of tubing that is not cut to size, we don’t care about the outer knuckles yet.  They will be adjusted to fit, after the soldering.  Find the center of the tubing and mark the center with the sharpie or scribe. Remember, the tubing should be a little longer than the metal.
  • You have two options on how to mark the central knuckle.  Option A: Since you now know your central knuckle length, go ahead and divide that number in half.  Using the 8mm example from above, that equals 4mm.  Draw a line 4mm to the right of the center line (that you drew earlier) and 4mm to the left of the center line.  This makes up our 8mm center knuckle.  Or Option B:  Lay the tubing into the groove, matching the center line on the tubing with the center line on the metal.  Using the marks you made on the metal, as a guide, mark the tubing for the center knuckle.  Re-measure the tubing and check your numbers. Are both the tubing lines  and the metal lines, 8mm? Note whether to saw (the tubing) to the left of your line, right of your line or dead center.  The thickness of the line can throw your hinge off – with this 3 knuckle hinge, it’s not as crucial, as we made the tubing a bit longer. But, get used to being accurate.  It will be important in all areas of jewelry making.
mark-tubing                                                    Option B

Back to the Metal

  • After marking the metal and the tubing, pry apart the glued-together metal with a bench knife or other wedge.
  • Remove the super glue with the torch (ventilate VERY WELL) or use either Acetone or Bondini Remover (again: Ventilate well!). Pickle and wash.

Back to the Knuckles

  • Cut the tubing into knuckles.  Use a tube cutter (Bergeon brand), 4 Angle Tubing Cutters or a tube holding and cutting plier for the most accurate cut.  Buy the best tubing cutter that you can afford.  There are some brands that have too wide of a slot for sawing and it makes it very difficult to make square cuts. Whatever method you choose, your knuckles need to be square and evenly cut.  They must fit together perfectly.  See my video:  Flat Square Edges on Sheet Metal, for methods on how to achieve this.

tubing-cut

  • Beveling the tubing: File tiny bevels on the ends of the tubing with an Equalling Needle File.  You need to file a very small bevel so that it doesn’t show. See the illustration below for bevel placement (the bevels are exaggerated). You want to bevel the tubing to discourage solder from running where it is not supposed to.  Here’s where that line, we drew earlier, comes in handy.  Bevel on the line – this way you know that the bevels are in the right place and aligned.

bevel-new

Soldering

  • Paint either Yellow Ochre or Whiteout along the interior, round ends of the tubing and along the seams where you don’t want solder to flow.

white-out

  • To hold the knuckles together for soldering either use graphite pencil lead, an oiled nail or oiled binding wire.  You want a snug fit, but not so tight that you can’t remove it.  If you use steel or iron, you have to oil it so that the solder doesn’t flow onto it.  The oil will be burned up in the soldering process – ventilate well.  You can use Olive Oil for this step.
  • Arrange the hinge and metal on your soldering surface. Use either a Charcoal Block, Ceramic Honeycomb or some other flat soldering surface to solder on. Push the lead, nail or binding wire  into the tubing and align the bevels on the tubing (using the line that we drew earlier).  Lay the metal, flat on its back, beveled/grooved edge facing up.  Carefully, place the tubing package onto the center of the groove.  You will probably have to rearrange the tubing to ensure that all is lined up.  Double check and check again that the knuckles are aligned.
  • Flux the tubing and the metal, ONLY WHERE YOU WANT THE SOLDER TO FLOW!  See the diagram below. You will have more control if you apply the flux with a small paintbrush.  Don’t flood the area with flux!
  • I recommend balling up your solder (use HARD solder – if possible, as it will create the strongest join).  Balled solder has less tendency to jump when the flux boils. To ball up the solder, cut tiny pallions, separate them from each other and direct the torch flame onto them.  They will ball up.  With a small paint brush, dipped in flux, pick up the balls and place them in the correct positions, snugly against the tubing.

solder-setup

  • Turn on the torch, again, and direct the flame towards the area with the most metal.  In the illustration above, that would be the metal areas.  Bring the torch tip towards the knuckles and watch for the solder to flow.  By heating evenly, you will avoid the solder jumping to one side.  You want the solder to flow down the groove AND the tubing.
  • Quench in water and then remove the temporary pin (binding wire, nail, leads), pickle, neutralize and wash with soap and water.  Don’t throw the whole setup in the pickle as you’ll end up with copper flashing all over your piece.
  • If for some reason, you end up with solder where it doesn’t belong (oh the shame!), re-heat until you reach the solder flow temperature and either with Soldering Tweezers (aka: Cross-lock Tweezers) or a Soldering Pick* knock the knuckles off.  Sand down the solder a little, to remove the skin – you don’t have to remove it all unless it makes the hinge uneven.  Start over with aligning, painting on resist, flux and adding solder.  Good luck this time.  Another option is to toss the whole thing and start anew.  Alas...the beginning of the “Box of Rejects”!

* Make your own soldering pick with a small dowel and a sharpened piece of iron coat hanger. First, drill a hole, a bit smaller than the wire, drop in some glue, shove in the wire.

Hinge pin: Testing and Riveting

  • Now, let’s test that hinge out!  Slide in your hinge pin and open your hinge.
  • If the pin slides in smoothly, move on to riveting. Your hinge should look like the illustration below, with most of the tubing showing on the back side.

soldered-hinge

  • If you skipped the beveling method your hinge should look like this:

nonbevel-hinge

  •  If your hinge pin doesn’t fit in, you may need to ream out the tubing to align it internally.  Use a Cutting Broach to do this.  The broach is a five-sided cutting tool that comes in a variety of sizes.  Put the broach into the hinge, slowly rotating it , one hinge at a time, clearing away metal.  Pull the broach out often, to remove metal buildup. Check the fit of the hinge pin, often.  Be careful to not remove too much metal.  Remember: tight fit!
  • Before riveting, remove the hinge pin. If you have a lot of tubing sticking out, past the metal, trim with the saw.  Don’t trim it too, too closely to the metal.  It is better to leave a bit and use the file to level it out.  Clean up the edges with sandpaper until they take on the finish that you want.
  • Re-insert the hinge pin.
  • Trim the hinge pin. Leave 1 1/4 to 1 1/2 mms of wire or tubing on each side of the hinge.  This will allow you enough material to securely rivet the hinge in place.
  • Another riveting method is to melt a small ball on one end of the wire (with the torch) and either rivet or ball up the other end – see image below. Use a cup bur to round and clean up the ends, after riveting or melting.

ballhinge

  • Another method for a hinge pin is to use a wire that is a bit too big for the hinge.  Point one end of the hinge pin.  Check for fit:  If it is too tight, you can thin the wire a bit by putting it in the flex shaft and spinning it on sandpaper.  You want the pin just tight enough to fit in. Care must be taken that it doesn’t warp or bend.  Watch your fingers.  Wear eye protection.
  • Holding one end of the wire in the flex shaft, insert the pin into the hinge and gently twist the pin in.  A big drawback to this method is that the wire can snap off in the hinge – then you need to drill it out.  A positive reason for using this method is that the connection between the hinge and the hinge pin are very tight.  You also don’t have to rivet it in as the tight fit will hold it in place.

hinge-pin-rotate

 

You are done with hinge #1!

  • When you move on to the next hinge (if you are doing a hinged bracelet), keep the prior hinge away from the heat of the torch, as much as possible.  You don’t want the other hinge un-soldering itself nope, you don’t!
  • When making a bracelet using the Butt Hinge, think about making a hinged clasp.  It will fit in seamlessly or stand out – depending on your design.

Some Final Notes on Research

Fabulous books and articles to check out:  

Thanks for taking this long journey with me.  Any questions or corrections please, let me know.  Take Care.  Nancy L:T Hamilton, the Not-So Lazy Jeweler!