Instructions for Use

Preparation of the Elements

Other than normal cleaning procedures, no special preparation is required. The best final cleaner is reagent grade or CP acetone.

Application and Curing

Prepare Type DC-90 by the addition of catalyst to cement in a clear glass container. Thorough mixing is important. While stirring, hold container up to the light and observe Schlieren Effect (streaks). When Schlieren Effect disappears, continue mixing for at least 30 seconds. The entrapped air in the cement will surface if the mixture rests at room temperature for a short time, or is briefly subjected to a vacuum of 625 mm Hg. The catalyst bottles have a specially designed controlled-drop tip, pre-calibrated at Summers Optical laboratories to an accuracy of ± 1%. To use, squeeze the inverted bottle, allowing one drop to fall at a time.

For 3 : 100 mixture, use 3 drops of catalyst per 3 ml of cement.

NB: The catalyst bottle supplied with Type DC-90 contains more than sufficient catalyst for a 3 : 100 catalyst : cement ratio.

Place the prepared LENS BOND DC-90 cement on the concave surface, and place the convex surface thereon. Press down firmly and gently until LENS BOND completely wets the matching surfaces. Then, with a slow rotary motion and light pressure, force air bubbles from between the lenses. Excess cement can be removed with a cloth slightly moistened with alcohol or acetone. (Please note: Excess solvent will remove cement from between the cemented components.)

After pre-curing with an ultra-violet black light, holding devices can be removed and the components be cleaned carefully. Before testing the transmittance, the lenses must be fully cured. Full cure time is in addition to the pre-cure time. If there is any doubt about cure being achieved, allow components to cure for a longer period of time. The cement will not “overcure”. If cure is not achieved in a reasonable amount of time, the catalyst ratio, mixing procedure, UV transmission of elements, distance of lamp and power of light source should be checked.

Safety Instructions

Although LENS BOND is quite safe to use, some persons may be sensitive to the chemicals, and therefore, should use finger cots or gloves. Furthermore, adequate ventilation should be provided.