Follow along below to see how you can fix the glasses with common household items and materials. The only special tool needed is a small gauge drill bit. I got mine for less than three bucks at a small town hardware store. If you're willing to take a risk and trust your skills with simple hand tools, you could have fixed glasses as soon as tomorrow!
Step 1: Things you'll need
Step 2: Lecture on gluing technique
Cleaning, Clamping and Curing.
Cleaning: you want the surfaces to be joined to be very clean and dry with a matte texture. The glue needs a solid, clean surface with a little "tooth" to bond to. Sanding lightly with fine sandpaper and washing with a household solvent should do the job. Let the parts dry thoroughly before gluing.
Clamping: You want the parts held steady relative to each other while the glue sets up. If the parts wiggle while they're bonding together, the bond is weakened.
Curing: This means giving the glue time to do its job - form a bond. If you strain the bond before it's fully set up, it will be weaker.
So, clean the joint well, clamp the parts together, let the glue cure and you'll have good results every time.
Step 3: Cleaning
Step 4: Making the Clamp
The first photo shows what you want: The piece of stir stick fits between the two side pieces of your glasses with a little overlap at the break. This will let you clamp the break together firmly.
The third and fourth photos show the piece of stick being wrapped in some wax paper to protect the lenses from being scratched by the stick. You could use the soft cloth to wrap the stick instead. Just make sure you protect the lenses from the stick.
Step 5: Clamping the glasses
This step can be quite fidgety:
Get both sides of the glasses held down to the stick with rubberbands. I doubled over a rubberband and slipped it over one end of the stick, then slid the end of the glasses under the rubberband. Repeat for the other side.
Now fiddle with the glasses and rubberbands until you have the ends of the break held firmly together. Scoot all the pieces around and together, being careful not to mar the lenses, until the pieces are lined up right and held snuggly together. Small voids between the two sides are okay as long as there are some firm points of contact and things are lined up well.
Step 6: Gluing the core joint
The basic steps are as follows:
Photo 1:Apply glue to the break. Make sure there are no air bubbles or gaps in the joint.
Photo 2: Gently, lightly, quickly, roll the side of a cotton swab over the glue to absorb any excess.
Photo 3: Set the clamped and glued glasses somewhere safe to cure for and hour or so.
Step 7: Drill holes for tension band.
The first picture is a preview of two steps ahead showing the band of thread wrapped through the holes you're about to drill. This is to help you visualize the holes you're about to drill.
When drilling, lay the glasses on a soft cloth. Be careful not to scratch the lenses. Be careful not to stress the core joint. Be gentle with the drill and brace things carefully with your fingers. Be careful not to drill a hole in your fingers.
Drill the holes far enough apart that the repair has a pleasing elongated shape. I think the example below has the holes a little too close together and the final result is a little bulbous. Don't make the holes too far apart or the tension band will sag on the bottom.
Step 8: Sew the break shut/Wrap the tension band
Thread a fine needle with a long enough length of thread. About 4 to 6 feet doubled over to 2 to 3 feet should do it. It doesn't hurt to have a little too much thread on your needle when you're done.
Take care while wrapping the tension band to make sure each wrap of thread is snug, but be gentle and don't stress the core joint.
Wrap as many turns of thread through the holes as you can. When the needle won't fit through the hole, then you're done wrapping.
Step 9: Glue the tension band
Make sure there are no air bubbles in the thread or holes. Make sure there is no air between the tension band and the core joint -- glue the two layers together.
Get everything soaked and then lightly blot by rolling a swab across the joint.
Let it cure for fifteen minutes, and then trim the threads with a hobby knife.
Step 10: First radial wrap and glue
Take a length of thread and tape one end to the top of the frame over one lens. Wrap the thread careful and completely across the bridge of the glasses.
Once the first radial wrap is complete, tape the far end down on the frames but DO NOT TRIM.
Soak the wrap in glue.
Blot lightly and let cure for a couple of minutes until no longer tacky.
Step 11: Reverse radial wrap, final glue and trim.
Having said that, smooth and tidy is still the order of the day. This is the final wrap of the repair, so make it look nice. This is the most boring part of the repair, but paying attention to detail here will give you a strong and attractive repair.
Soak the final wrap in glue.
Let it cure for a couple of minutes. Trim the ends.
Set the glasses somewhere safe to cure for 24 HOURS. Skimping on cure time can weaken the repair.