Three key points to keep in mind when cleaning mirrors
Dec. 18, 2021
The recommended procedure for cleaning optics is generally the same whether you are using a lens or a mirror. A typical cleaning process involves first blowing dust and dirt off the optical assembly with pressurized air, then slowly moving moistened lens paper across the optical surface using the dragging method.
Three key points to keep in mind when cleaning mirrors are as follows.
1. Clean only protected mirrors - Bare metal coatings are fragile and can be easily scratched when cleaned using conventional procedures. Only clean mirrors with an enhanced or protected surface coating in this manner. If you must clean unprotected mirrors, use only compressed air - do not use paper.
2. Do not use dry lens paper - Using lint-free lens paper dipped in cleaning solution is important for cleaning lenses and properly coated mirrors; however, mirrors are especially susceptible to scratches from dry materials. Be sure to moisten the paper with a chemical solution before cleaning. This brings us to the last point ......
3. Use the best reagent - When selecting chemicals for optical cleaning, usually choose 97-99% isopropyl alcohol, methanol, acetone or a mild detergent. Reagent grade alcohol and acetone are most commonly used to clean mirrors, with alcohol usually preferred. It evaporates more quickly than acetone, thus avoiding spots and streaks.