What NOT to do with a secondary mirror

[Sirius_Starseed]

If you've read my last two threads you'll know that yesterday when I was trying (trying being the optimum word) to collimate my 130P with my new Cheshire I loosened the main screw of the secondary too much and it fell off and hit the inside of the 'scopes main tube It chipped the top of the secondary mirror and in my panic crazed frenzy I picked it up and touched the mirror putting two thumb prints on it. I came on here to ask for advice and a couple of people told me to try glueing the piece back on..... so that's what I did........... BIG mistake! The 'scope now 'ghosts' with poor image quality. So basically what I'm trying to tell any other newbies is DON'T, whatever you do try and glue the chipped piece back on. You won't be able to see properly and you'll get a ghosting effect.

Anyway, after getting more advice I've cleaned the secondary using cool, lightly soaped water, wiped once (very gently) with a wet cotton wool ball, and then rinsed with cool water. It has now come up very clean with no signs of marks or fingerprints. The chipped piece which I glued on actually came off in the water so I've left it and just painted the chipped mirror with matt black glass paint which I fortunately found in my Dad's garage. Hopefully after all of this it will be fine. Some nice folks from the East Midlands Star Gazers group said they'd help me collimate my 'scope so I'm gonna leave it now until I get down to the next meet up. I just can't bear the thought of messing anything else up.

So yeah, whatever you do, DON'T glue a chipped piece back onto the mirror. Just throw away the chipped piece and paint the chip with black glass paint or a permanent marker pen.

Lesson learnt

[AndyH]

OUCH !

:eek:

Those chaps will get it fixed for you.

Andy.

[Hypernova]

Just be thankful that the secondary didn't land on the primary

[starman345]

Sorry to hear about your bad luck. I'm new at this astronomy stuff and was playing with my scope trying to collimate with my new Hotech and loosened the main screw of the secondary mirror like you did and it nearly fell, fortunatly the screw was holding by a thread so no damage but I know how you must have felt, my heart was in my mouth.

Hope your mates can get things sorted for you and get you back gazing at the skies.