Cleaning dusty mirrors

[Granada]

Is there a simpler way to clean a dusty primary mirror on a large Dobby that doesn't require a full disassembly? Is dust even a big issue (mine has a thin layer, since the scope was used about a year ago).

[multiweb]

Without looking at the mirror I'd say try to blow as much as you can first. If it's really stuck then you'll have to wet the primary and losen the layer before wiping it.

[Granada]

Thanks Marc. Any way this can be done without disassembly? I'm guessing just water would do the trick, and a gentle wipe without any pressure using a sponge?

[multiweb]

I'd take the mirror out but if you want to do it in situ I'd use a bit of distilled water and kimwipes then one stroke from center to edge, change the wipe everytime and do the whole surface or what needs to be done this way.

[doppler]

I take the mirror out but leave the mirror in the cell and carefully wash the surface under water (with a couple of drops of detergent) in the sink. Final rinse with distilled water. I mark the orientation of the mirror cell in the ota so it needs very little collimation when re installed.


I have heard some people use their finger tips to wipe the surface in lieu of a soft cloth, the finger tips are apparently softer/ smoother and you can feel any grit that might otherwise scratch the surface.