How quickly does muck normally accumulate on dob mirrors?

[Orange Smartie]

An idle question perhaps, but something I'd be interested in understanding:

I have a Heritage 150p dobsonian, which I bought at the start of the year.  I've used it at nearly every possible opportunity, so it has spent a fair few hours outside.  I found that it had a mark on the mirror surface, which I think was probably there from new (I suspected a manufacturing flaw), but the general crud is building up in spite of being stored upside down on the mount with caps on etc.  I don't have any kind of lightshield on the sides of the tube, so when fully extended there is more likelihood that things will fall in.  I'm not concerned at all about the optical performance of the telescope - it works fine.  However I am interested in knowing how quickly you would expect to see dust/dirt collect on the mirror, especially since I am getting a 10 incher at some point and anticipate mirror anxiety!

Pete

[westmarch]

Hi Pete,

After getting mine second hand I washed the primary using mild soapy water and rinsed with distilled water and it came up fine - there are a few Youtube vids to assist. 

I used to store the scope in the dining room because of the same anxiety about muck and mildew but my wife got fed up with that. I have since moved it to the garage with very little increase in crud accumulation.  Of course, not all garages are equal and muck accumulation phobia may be replaced by accidental damage anxiety. 😁 It does make cooling down quicker though.

Like you, I have a truss dob and store it with a cap on the mirror,  another on top of the open end and the light shroud on. It does take a lot of muck to affect the visual performance so I try not to get too worried about it.

John

[jacobingonzo]

as above my Dob accumulated crud from the get go- dont worry takes a lot to affect performance -if you are starting to get sleepless nights just wash the damn thing lol.

 

J

Edited April 15, 2021 by jacobingonzo

[Orange Smartie]

8 minutes ago, jacobingonzo said:

as above my Dob accumulated crud from the get go- dont worry takes a lot to affect performance -if you are starting to get sleepless nights just wash the damn thing lol.

 

J

Unfortunately I worry about everything! But point taken.

[jacobingonzo]

Yes indeed ,Totally understand but I have learned its best not to worry- use this forum to help dispel any worries, there are many friendly beardy  pointy headed folk positively straining at the leash to offer a helping hand

 

J

[Quetzalcoatl72]

I got my ritchety chreiten scope recently and after just 3 uses it was quite scarmy, assuming dobs are worse, heard multiple time's it doesn't effect the images, on camera sensors do

[Spile]

This may help you decide...

https://astroanecdotes.com/2015/03/26/the-mcdonald-gun-shooting-incident

[Orange Smartie]

1 hour ago, Spile said:

This may help you decide...

https://astroanecdotes.com/2015/03/26/the-mcdonald-gun-shooting-incident

No bullet holes yet, I'm pleased to report.

[Spile]

15 hours ago, Orange Smartie said:

No bullet holes yet, I'm pleased to report.

If you decide to clean your mirror because of a bit of muck, then I guess you are going to want to repeat the whole process in six months or so?

Resist the dark side.

[Orange Smartie]

19 hours ago, Spile said:

If you decide to clean your mirror because of a bit of muck, then I guess you are going to want to repeat the whole process in six months or so?

Resist the dark side.

Agreed. This is why I was interested in knowing how fast I could expect the mirror to get dirty and whether the rate of accumulation of muck on mine is typical.

[westmarch]

Those who get their mirror out most see more..... regardless of muck. 😉  Enjoy these cloudless nights and (relatively) low jet trail pollution.

John