Cleaning help

[richbyers]

i have a truss tube 130mm dobsonian which i have noticed has collected some black dirt in the bottom of the scope on the primary mirror

whats the easiest/cheapest/best way to go about cleaning this?

thanks

rich

[John]

As it's a truss tube design presumably you have access to the mirror without removing the mirror cell ?.

I'd try a high powered blower brush (manual not pressurised) and blow as much of the dirt off without touching the mirror surface. I'd only wash the mirror if it's really filthy - it takes a lot of muck to affect the performance of a mirror and washing is not something that you want to do too often.

[richbyers]

yes thats correct

ok cheers ill give that a go

rich

[Rob]

Only wash it if REALLY need to. Air blow the dirt away and all will be fine, even if traces left. I used a Orion Optics GX250 once where I could not see my face correctly in the mirror when I looked down the tube, it was that bad.. swung it round for a look at m13 and had one of the best views I'd ever managed!!..

So thats proof enough to me that you should not worry about a little dirt on a mirror.

Rob

[richbyers]

haha sounds good enough to me, should come off easy enough