Repair Garmin FR15 / 70's broken wristbands

Garmin FR15/70 wristbands are susceptible to breaking after a year or two of daily use. Clone FR15 wristbands are available from China sellers. However, shipping & custom clearance may take several weeks and so, an interim fix may be required, especially if one is a daily exerciser. As for FR70, the wristband is part of the watch body and therefore, is irreplaceable; so, hacking a solution is mandatory.

Material list: cyanoacrylate glue ("Superglue"), heat shrink tube (dia. 16mm), contact adhesive.

1. Clean the broken ends.
2. Apply cyanoacrylate glue to the ends and then bring them together.
3. Hold for ~60s while the glue hardens.

At this stage, the wristband has been rejoined, but the butt joint's small contact area is unable to withstand much tension load (pulling). To increase the joint's resistance to pulling, the joint area is enlarged in the subsequent steps to create a double lap joint.

Gluing the wristband's broken ends forms a butt joint. However, the joint's small contact area is unable to withstand much tension load (arrows)

Heat-shrink tube over the wristband approximates a stronger "double lap joint"

 
4. Cut a piece of heat-shrink tube with sufficient overlap to cover the break.
5. Clean the wristband surfaces that will be later covered by the heat-shrink tube.
6. Slip heat shrink tube over the wristband, but slightly away from the break.
7. Apply contact adhesive to the wristband' surfaces (contact adhesive allows the joint to flex).
8. Apply contact adhesive to the inside of the heat-shrink tube.
9. Leave contact adhesive to dry for ~15 minutes
10. Slide heat-shrink tube over the break.
11. Apply heat (e.g. hair dryer) to the heat-shrink tube.
12. Leave overnight for the bond to cure to full strength.