EDGING

 
 

1. Polycarbonate can be edged using present CR-39 procedure with slight modifications using a dual propose
    CR-39 / Poly Wheel.
2. Use the dry edging for polycarbonate lenses. Coolant should be turned off until the last one or two cycles.     This will makes the lens edge brighter.
3. Clean the edge machine regularly. If there are chips sticking on the diamond wheel, clean them with oil     stone or sharp pick.
4. Adding a filter at the end of the water pipe from the edge machine to filter the edging chips.
5. Take down the bigger chips carefully from the lens edge when they are found during the edging process to     smooth the edging work.

 
     
 

PIN BEVELING

 
 

1. A standard ceramic wheel may be used. Dry beveling is preferable as wet tends to load wheel and is     slow.
2. If chips are found at the edge of the lens, use single edged razor blade to remove. Be carefully not to     damaging the lens.

 
 

 

 
 

GROOVING

 
 

1. Use standard CR-39 grooving machines dry.
2. If chips remains in groove, use a pick or single edged razor blade to remove.

 
     
 

DRILLING

 
 

1. General drilling machine can be used. However, use sharp drill is important. A dull drill will melt the material     plus add stress to the lens. Adjust speed of drill to approximately 160-180 RPM.
2. Clean the chip in the drilling hole by a tooth pick or tiny stick.

 
     
 

POLISHING EDGES

 
 

1. Use standard CR-39 techniques with a buffing wheel and polishing compound. But, use softer and delicate     polishing cloth. Green oil polishing earth is recommended.
2. Use slow speed on buffing wheel and less pressure than CR-39 to minimize stock removal and heat
    build-up.

 
     
  GLAZING  
 

1. The rule to keep in mind when glazing PC lenses is to eliminate stress to the lens from improper sizing,     mounting or excess tightening of screws. Stress will eventually lead to the crazing or cracking of the lens -     usually days or weeks after dispensing.
2. The crazing or cracking will usually appear and localized fine hairlines radiating inward from the overly     stressed area of the edge of the lens or from an overly tightened screw mount. Occasionally, if the lens is     evenly oversized, the equal stress will result in the center of the lens cracking.
3. Inspect mounted lenses using a polariscope. Excessively stressed areas will appear as bright colors,     usually purple and yellow. Hand edge or loosen the screw until the stress is removed.
4. With screw mounts, use inserts or washers where possible.