Rain marks on Dobsonian mirror

[Rapallokid]

Thanks for all the replies, all good guideance.

I did run my fingers over the mirror under running water after cleaning it and can feel whatever it is on the surface.

It still wont budge, warm water, liquid soap, alcohol !!!!

I will stick with it for now and see how the resolution is when viewing, assuming i can get it collimated again ;0(.

If all else fails I have come to an agreement with the person I bought it from to have it re mirrored at his cost. Cant say fairer than that.

[blinky1983]

Thats good mate... Well just a few mins ago I had my scope in the kitchen was gona take it out to cool down. Then my wife walks by it holding a cream cake and then .......... Yep fell inside my ota and splat all over my mirror..

Try leaving your mirror over night in a soap and warm water, Stirring the water now and then.. cover it up with a tea towel or something to stop any dust hair etc etc falling into your water..

[gdheib0430]

Yep fell inside my ota and splat all over my mirror..

QUOTE]

Priceless all I could have done was laugh after my deer in the headlights look for a few minutes hahaha.

[midjam]

Thanks for all the replies, all good guideance.

I did run my fingers over the mirror under running water after cleaning it and can feel whatever it is on the surface.

It still wont budge, warm water, liquid soap, alcohol !!!!

I will stick with it for now and see how the resolution is when viewing, assuming i can get it collimated again ;0(.

If all else fails I have come to an agreement with the person I bought it from to have it re mirrored at his cost. Cant say fairer than that.

Hi Rapallokid,

Did you ever get that stuff off or did you get a re-coat? I have the exact same problem, my mirror looks the same as your pics.

[Steve Ward]

DISTILLED water , Not De-Ionised

[midjam]

Here's some photos of mine

I cleaned it using warm water, few drops of washing up liquid and cotton buds (i was very careful this method worked great for my 4.5"). They were still there so, left it to soak for around 20mins but, still no joy.

The water seems to beat off the mirror a lot more than it did with my 4.5" which leads me to think it might be tree sap, oil of some kind. In this article they mention using a water/alcohol mix;

http://www.bpastro.o...-ritchie-mirror

Thinking of giving that a go but, I'm a little worried about doing more harm than good. The guy I brought it from says it doesn't effect the image quality, haven't had a chance to test it out myself yet however, I would not notice anything different as this would be the first time I have looked through such a powerful scope.

I guess I have a little bit of OCD when it comes to image quality

When I shine a torch through the top of the mirror I can see brighter patches of light is this normal?