Hard Coating Specs

**CReagle** · 06-14-2011, 02:05 PM

We use Ultra Optics M/R III and are coating Hi Index 1.60 and 1.67 as well as poly. We see twice as many specs on the Hi Index / high curve lenses (sun wear) as on our poly lenses with lower curves. We use separate machines and different coating for Hi Index as opposed to the poly coating. Other than that the machines are set up the same and to factory specifications. The specs appear to be small bubbles or bubbles that have popped. They are pretty random. We have a clean room environment. Does anyone have any suggestions for what settings I can try adjusting? Thanks.

**DragonLensmanWV** · 06-15-2011, 10:19 AM

Sounds like air in the coating pipes. Try bleeding the air out at the filter.

**Jim Schafer** · 06-21-2011, 10:43 AM

Make sure the lens is dry, no water spots.

It has been years and years, Back in the late 80's we had Ultra Optics machines to hardcoat the Transitions lens prototypes in our pilot plant. We saw defects as you described before curing and found that we needed to keep an eye on the water delivery system. If I remember right, changing filters and cleaning the spray nozzle corrected the "crop circles".

Jim

**PRECISIONLAB** · 07-29-2011, 03:56 AM

As in previous posts, most coating defects are the result of the lens not being dried properly. The spray nozzle is usually the culprit. Also try a drying additive to your wash water such as 90% alcohol or some other evaporative. You asked for an adjustment..I would varify the "sweep" angle of the wash and dry assembly in wash bowl. Changing the position of the pivot may give you a larger sweep area to insure the entire lens surface is washed and air dried. Be sure to index original position just in case adjustments worsen the problem.