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What tapes to use for masking a part of lens when doing coating?

2001

Hi friends,

I need your help on masking. Here it is: I want to make aluminum mirrors using vacuum coating techniques on a lens, BUT want to leave the center part out---i.e: do not coat AL on the center of the lens. I have heard that people use some kind of tape as a mask.

The questions are: (1)what kind of tapes are good for vacuum coating(cold coating)? (2)What do you do to mask a shape like circle or square--how do you cut the tape into those shapes?

Your responses are highly appreciated.

Charlie Smith
- El Paso, Texas

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If the temperature of deposition stays below 200C then Kapton tape is usually used in a vacuum system because it outgasses very little. The best way to make a circle or square of tape is use scissors. Simple but effective.

John Davis
- Berthoud, Colorado, USA
2001

You can cut the shapes with scissors, but obviously, this can be time consuming. If you need the shapes to be consistent, you would be better to have them die cut for you. This way you can just peel them off a roll and apply them.

John Gill
Santa Fe Springs, California, USA
2001