cleaning my telescope

[keiwein1]

i just bought some zeiss lens cleaning wipes and it comes with microfiber towel an eyeglass cleaning liquid and the wipes... i dont want to damage my telescope (again) so i want to know how to clean an 8 inch SCT. thx in advance!

[Dave In Vermont]

Regards the primary-mirror, the big one with a hole that is inside the scope's tube - you don't unless there is a very good reason to disassemble your telescope. Operative word: Don't.

As for the corrector-lens in the front, why do you believe it needs cleaning? This is another case of: Don't - unless it truly needs it. Please explain what your situation is? Some quick photos would be a big help here. Those little digital cameras should be on everyone's shopping-list.

Please let us know.

Dave

[seo]

+1 to what Dave wrote you.

Case a : To clean the primary you have to remove to corrector.

Case b : To clean the internally the corrector you again have to remove it.

Case c: To clean both of them you again have to remove the corrector. 

Possible bad result in all cases : You'll mess up your telescope collimation ! 

So, unless you know very well what you're doing, how exactly to clean your scope without scratching your primary or/and your corrector and how to fix the possible de-collimation don't do it ! If the "situation" really needs cleaning better leave someone professional to do it.

That's my humble opinion.

Clear skies.   

[Joe12345]

What I do to clean my scope it is unscrew the screws at the back of the primary, which although doesn't let you remove it, you can still rotate it 90* which should let you see enough of the mirror to clean it. The only disadvantage to this is that when I did it, 3 small rubber rings fell out - I haven't noticed any different but don't know where they go! I wouldn't try this yourself though unless someone says it will work.

[CodnorPaul]

Echo the above - don't do it.  The primary will unlikely need cleaning as it is a closed tube - never touched mine and it remains spotless.

I have cleaned the corrector once VERY CAREFULLY and to be honest didn't notice any difference at all so unless it is really bad again don't touch.  I cleaned mine 3 years ago now and it still looks clean enough.

With an SCT as long as you are using dew control and ensuring it goes away dry then very little muck generally sticks on them, counting out tree sap etc depending on where you view.

[Dave In Vermont]

What I do to clean my scope it is unscrew the screws at the back of the primary, which although doesn't let you remove it, you can still rotate it 90* which should let you see enough of the mirror to clean it. The only disadvantage to this is that when I did it, 3 small rubber rings fell out - I haven't noticed any different but don't know where they go! I wouldn't try this yourself though unless someone says it will work.

I'm sorry to say this - but this is a perfect example of why not to try to clean the primary. Joe12345, above, got off easy so far. I don't care to speculate what the unknown rubber-rings were used for, but I'm sure they weren't there without a symbiotic purpose as part of a necessary system. But Joe is 12 years old, so the Telescope-Gods may have gone easy on him.

Another caveat is this: Do not use a flashlight - torch to you all in the UK - to determine if your primary or corrector-plate are dirty. Even optics that are flawless in regards to their performance, under the light of a flashlight~torch can well resemble a World War I battlefield!

Finally, if you want the information for the sake of having it, this will take you to the website of Dr. Clay Sherrod - a well-known expert in the field of SCT's and their maintenance and improvement. These are his cleaning instructions:

http://www.arksky.org/asoclean.htm

Don't -

Dave

[brantuk]

+1 for don't do it - it don't know what the fascination is with cleaning scopes - they rarely need it and only in the worst circumstances (when dirt is thick on a mirror or some foul susbstance is stuck to the mirror/lens). With a Mak or Sct you additionaly need to know how to collimate it - most of us avoid this cos it's very involved.

If your Sct needs servicing and cleaning send it to a pro who will know exactly what to do. Mirror cleaning and collimation is usually only done on Newtonians which expose the mirror to the elements and are much easier to collimate. Hth

[happy-kat]

Specs of dust on the lens are not seen when using a telescope.

[LukeSkywatcher]

If you think your scope lens/mirror is dirty and needs a clean, just do an image search for the 12" mirror (i think) at the Kielder obsy. It was/is thick with dust but is still in use. It was shown on S@N a couple of yrs ago. It was quite something to see.

[damnut]

Another vote for not touching it!! especially the primary.

I had a 10"lx 200 and took advice and read up before cleaning the corrector If you must do it :---

1. Make some marks on the tube and retaining ring.

2. If in forks lock up at 45 deg.

3. remove carefully the little screws holding the corrector ring in place.

4. remove corrector plate, note that there may be some small pieces of packing. These must be kept and put back exactly where they came from.

5. Clean using baader wonderfluid and micro fibre cloth. Do not use this on mirrored surfaces.

6. Put corrector back in exactly the same position and re-assmble.

[paul schofield]

Stand back and leave that baby alone. Unless your scope becomes unusablly filthy, it really is not worth pulling it to bits to clean, believe me, I've done it & it just isn't worth the hassle' I had. My previous telescope mirrors were shockingly dirty, cleaned them, made no difference. If anything, it came out a lot worse. The mirror on my small 130 scope is in a terrible dirty, pre owned unloved state, and when collimated correctly still works like a dream. I used to think if my mirror had dust on it, it would not work so well (ocd' n all that) but that's just not the case. If one of my scopes becomes so bad (never happened) I would be inclined to buy again rather than clean mirrors etc. In my opinion, it ain't worth it. ........I'm gonna get member blasted now.

[DoctorD]

Hi

If it ain't broke don't try and fix it - I know it can be difficult to see a spot of dirt on your pride and joy but leave it alone.

Bear in mind that you have an obstruction the size of the secondary in the light path - what affect do you think a few specks of dust are going to cause?

At worst you might notice a slight reduction in contrast due to scattered light but it would have to be pretty dirty before you really noticed any degradation in the views.

I've had my SCT for more than 17 years and not cleaned it.

Hope this helps

Paul

[mcolbert]

another vote joining with the others.  My first scope was an old orange C8, had it for five years or more - never touched it once (to clean it that is).  Never a problem with viewing or images.

michael

[Herbig]

I have had a Celestron C8 XLT for 6 years now and only cleaned the outside of the corrector once as it got pollen on it. As said above I used Baader wonder fluid and Baader micro fibre cloth. Do not spray the fluid onto the corrector, moisten the cloth. If you spray it onto the corrector it is possible for it to seep inside.

[cjdawson]

Had my scope for 15 years. Think I cleaned the outside of the corrector plate once about 5 years ago. No plans to do it in the next few years. And I have no plans to ever remove the corrector. Again +1 to don't do it.