The adhesive in fiber-optic hot-melt connectors tends to set up slowly after heating. Although you wait, as you should, until the connector is cool before you attempt to cleave the excess fiber from the tip, sometimes the glass will still break below the tip of the connector, resulting in a faulty connection.
If this happens, the connector can be salvaged by reheating it and reconnecting the optical fiber.
1) Reheat the connector and apply just enough pressure from below to the optical fiber--while gently squeezing the clear strain-relief tubing--to push its end about one-sixteenth of an inch above the connector`s surface.
2) Allow the connector to recool for a few minutes while maintaining light pressure on the strain-relief tubing. This will prevent the glass from backing out again. Canned air can be used to help in the cooling process.
3) Polish the fiber, but be careful not to apply too much downward pressure on the connector in the puck. Remember that there will be no bead of adhesive on the fiber tip to support the glass, if too much fiber protrudes from the connector`s endface after reheating.
Be aware that polishing will take less time because of the lack of adhesive. Overpolishing may cause a concave fiber tip, resulting in poor test results and possibly high signal loss during use. Also be careful not to frost the connector if canned air is used to aid in cooling.
Reheating the fiber endface and pushing up the optical fiber slightly make it possible to repair a faulty cleave.
Jamie Bytheway is lead technician at Teldata (San Diego, CA). He is also the owner of nettech Communications Cabling Specialists (Fort Smith, AR).