I suspect I have a telescope disaster!

[Stu]

18 minutes ago, Gina said:

Got it a bit better but I think it needs a lint free cotton cloth and distilled water.  Or maybe Baader Wonder Fluid and cloth.

Wonderfluid and a fresh cloth should do the trick. Glad it is a much better outcome than expected! Phew 👍😁

[JamesF]

Yes, I found my SCT needed several attempts to get it completely clean again.

James

[sloz1664]

That's great news Gina. It certainly made me think. I've now checked all my equipment  and ensured everything is tickety boo.

Steve

[JOC]

Have just found this thread - glad everything seems to be coming clean Gina - those first pics looked a bit of a disaster.

Edited July 2, 2019 by JOC

[Carbon Brush]

Great news the muck is shifting.

I would be wary of using neat IPA. I (and others) have known it damage the coatings on spectacle lenses. Yes plastic lenses so different, but better safe than sorry.

An IPA/water mix is less risky.

A big thumbs up from me for Baader wonder fluid.
I had a really filthy mirror. After some time in the washing bowl I finished it with Baader fluid and no streaks.

Good luck with the clean.

David. 

[Gina]

I've ordered Wonder Fluid and cloth from FLO - thought I might as well do the job properly.

[Greymouser]

23 hours ago, Gina said:

I've ordered Wonder Fluid and cloth from FLO - thought I might as well do the job properly.

I have been looking at this thread and considering the horrible shock you have had Gina, when you discovered the discolouration. It must have been horrific to be honest and the thought of such happening, has so far put me off storing my kit outside the house. I too have bought some wonderfluid recntly, just in case a major issue, but also to clean an older eyepiece and a telescope that was in a loft for years. ( Dry loft though! )

With my apparent paranoia in mind and considering another fairly recent purchase of mine, have you considered such as this from FLO?
https://www.firstlightoptics.com/dew-prevention/flo-125-2-inch-desiccant-cap.html

They are desiccant caps that fit in the eyepiece holder part of the scope. I am not sure just how effective they are, the are only a small amount of desiccant, but they give me some piece of mind in my SCT telescope. Even though I only store them in the spare room!

Just a suggestion like, for future piece of mind... 

[Gina]

That's a good idea.  I have a bagful of desiccant sachets which I got to use in my all sky camera casing.  I can easily design and 3D print a holder like the one on FLO.  Though whether the scope is sealed I rather doubt.  There is bound the be a small gap around the focus tube if nowhere else but I think I'll give it a try.  The silica gel desiccant I have also changes colour when it has absorbed water - from orange to green.

[Greymouser]

19 minutes ago, Gina said:

I can easily design and 3D print a holder like the one on FLO

Perhaps I should have come to you first then, rather than FLO, seeing as you are a wiz with that 3D printer? 😉

[Carbon Brush]

A vote here for the FLO desiccant caps. I have a few.

In practice the focus leakage on 'closed' scopes, MAKs, fracs and the like, is minimal.
A small bag of silica gel absorbs only a small amount of moisture compared and the OTA volume can be high.
This means remembering to change (or oven dry) the bag every couple of months is more important than leakage.

My MN78 has a hole for a fan - I suppose a 3D printed blocking cover could replace the masking tape currently in use!

David.

 

[wimvb]

33 minutes ago, Gina said:

That's a good idea.  I have a bagful of desiccant sachets which I got to use in my all sky camera casing.  I can easily design and 3D print a holder like the one on FLO.  Though whether the scope is sealed I rather doubt.  There is bound the be a small gap around the focus tube if nowhere else but I think I'll give it a try.  The silica gel desiccant I have also changes colour when it has absorbed water - from orange to green.

The mn190 isn't completely sealed. I believe the holes in the corrector ring are for venting. Some people have installed a fan behind the primary mirror. That would be pretty useless if the tube were closed everywhere else. But a desiccant cap in the focuser is a good idea. I think the cheapest solution would be an old film canister with holes in the bottom. Very much like a diy collimation cap, but now with the lid on.

[Gina]

I guess I could print a cap to cover the corrector ring and seal that end for storage.  Yes, there's a cover on the mirror end that is presumably so that a fan can be placed in the hole.  I did wonder where the air would come out!  Although there are holes in the ring, the lens seemed to fit the ring without any gap so I still can't see where the air comes out.  I could take the ring off again and look...

[pete_l]

On 02/07/2019 at 17:23, Carbon Brush said:

A big thumbs up from me for Baader wonder fluid.

I had a really filthy mirror. After some time in the washing bowl I finished it with Baader fluid and no streaks.

The FLO page says wonderfluid is not suitable for cleaning mirrors. I wonder why? Though we are always told to "dab" not rub, when cleaning optical surfaces. Due to the risk of picking up grit and scratching the surface.

[wimvb]

20 minutes ago, Gina said:

I guess I could print a cap to cover the corrector ring and seal that end for storage.  Yes, there's a cover on the mirror end that is presumably so that a fan can be placed in the hole.  I did wonder where the air would come out!  Although there are holes in the ring, the lens seemed to fit the ring without any gap so I still can't see where the air comes out.  I could take the ring off again and look...

Or I could be wrong. Wouldn't be the first time.

8 minutes ago, pete_l said:

The FLO page says wonderfluid is not suitable for cleaning mirrors. I wonder why?

Most often mirrors have an aluminium reflective layer with a silicon dioxide protective layer. I've never seen a contents description for wonderfluid, so it may contain chemicals that can react with the Al layer. Just a guess. AR layers on glass, and filter coatings are very hard, and less prone to chemical reaction.

[Gina]

15 minutes ago, pete_l said:

The FLO page says wonderfluid is not suitable for cleaning mirrors. I wonder why? Though we are always told to "dab" not rub, when cleaning optical surfaces. Due to the risk of picking up grit and scratching the surface.

I'm glad you pointed that out - I missed it!  Thank you.
 

[tonyowens_uk]

Gina I have a couple of Intes-Micro Mak-Newts so I've experienced your issues. If you have time to do the job properly I'd follow Peter's advice and remove the cell and service the corrector and secondary properly. Marking the joints between every part with a small permanent Sharpie pen beforehand. Change the fasteners for stainless ones and either use silicone grease on the threads or seal them with a low strength loctite retainer. RS and Farnell have this. Warm the cell laid flat on a sheet of clean tissue in your domestic fan oven to 60 degrees, then remove and use good quality hex wrenches on the screws and they should release. If you manage to ream the head of one, carefully drill the head off using a Dremel and remove it that way. There are various ways to extract the remains, once the precious corrector and folding mirror are out of the picture.

Cleaned, reassembled and collimated it should be as good as new or better. If not, we have a high resolution Shack Hartmann analyser and a certified 1/10th wave autocollimation flat big enough, over here. I'd be happy to sort out any alignment problems you encounter FOC.

 

Tony Owens

[Rusted]

I used to store my four refractors upright on their dewshields in the same shed where I have my various powered saws.
The gap around the old Vixen focusers went completely unnoticed.
That is, until I found my refractors almost opaque to any light after a few months.
That was mostly astro inactivity and a considerable excess of sawing on the obs. build.
I kept a loose poly bag over each OTA focuser after a good clean out.
Makes me wonder how much sawdust went down my lungs! Cough! Spit! Ting!!

[Stub Mandrel]

Phew, only just seen this thread - like reading a thriller! Let's hope the wonder fluid is suitably wondrous!

" dislodges dirt, aggressive aetherical oil " - sounds pretty wondrous...

Accpording to teh web it's called 'Optical Wonder'

The MSDS says:

"2. COMPOSITION/INFORMATION ON INGREDIENTS
Chemical nature : (Preparation)
Description : Solution of the following substances with harmless additives.
Components CAS-No. EC-No. Symbol R phrase(s)
Concentration
Ethanol 64-17-5 200-578-6 F R11 25%
Propan-1-ol 71-23-8 200-746-9 F, Xi R11, R41, R67 35%
For the full text of the R phrases mentioned in this Section, see Section 16."

Presumably the harmless additives are a tiny amount of surfactant?

Edited July 3, 2019 by Stub Mandrel

[tonyowens_uk]

2 minutes ago, Stub Mandrel said:

Phew, only just seen this thread - like reading a thriller! Let's hope the wonder fluid is suitably wondrous!

Accpording to teh web it's called 'Optical Wonder'

The MSDS says:

"2. COMPOSITION/INFORMATION ON INGREDIENTS
Chemical nature : (Preparation)
Description : Solution of the following substances with harmless additives.
Components CAS-No. EC-No. Symbol R phrase(s)
Concentration
Ethanol 64-17-5 200-578-6 F R11 25%
Propan-1-ol 71-23-8 200-746-9 F, Xi R11, R41, R67 35%
For the full text of the R phrases mentioned in this Section, see Section 16."

Presumably the harmless additives are a tiny amount of surfactant?

Not sure. But washing broadband multicoated lenses is not rocket science and is low risk. There are not many moisture sensitive glasses used in astro correctors and eyepieces that are not BBAR coated and therefore quite cleaning-resistant. You need both organic and inorganic solvents to wash the lens then lots of DI water to flush. Mechanical cleaning by wiping with soft wetted tissue is a good idea provided scratching is minimised. Do the work in a plastic bowl and warm the diluent water. Whatever about high priced wonder fluid, there is nothing wrong with good old screen wash concentrate, diluted down with clean water. This contains alcohol/s plus a little acetone, in an aqueous base. Plus cool looking blue dye. Very important to flush several times with DI water. Car accessory shops will have this too! Dry by arranging in a rack (dishwasher drawer?) and gently using clean compressed air to blow off the drops. Not rocket science...

 

Tony

[Gina]

17 hours ago, tonyowens_uk said:

Gina I have a couple of Intes-Micro Mak-Newts so I've experienced your issues. If you have time to do the job properly I'd follow Peter's advice and remove the cell and service the corrector and secondary properly. Marking the joints between every part with a small permanent Sharpie pen beforehand. Change the fasteners for stainless ones and either use silicone grease on the threads or seal them with a low strength loctite retainer. RS and Farnell have this. Warm the cell laid flat on a sheet of clean tissue in your domestic fan oven to 60 degrees, then remove and use good quality hex wrenches on the screws and they should release. If you manage to ream the head of one, carefully drill the head off using a Dremel and remove it that way. There are various ways to extract the remains, once the precious corrector and folding mirror are out of the picture.

Cleaned, reassembled and collimated it should be as good as new or better. If not, we have a high resolution Shack Hartmann analyser and a certified 1/10th wave autocollimation flat big enough, over here. I'd be happy to sort out any alignment problems you encounter FOC.

 

Tony Owens

I'm having a problem understanding this.  The screws I can't undo are the ones holding the lens cell in the tube.  The ones holding the ring in the cell came undone easily.

[tonyowens_uk]

3 minutes ago, Gina said:

I'm having a problem understanding this.  The screws I can't undo are the ones holding the lens cell in the tube.  The ones holding the ring in the cell came undone easily.

OK. I was talking about how to remove and refurbish the entire cell complete with optics as a unit. Can you mark and extract the optics from the cell/tube assembly and get them out of harms way? If so, provided you photograph and carefully replace any lateral and axial shims used to centre the corrector, you could of course just decide to leave the cell alone. It would not be my choice (I dont take any nonsense from mechanical assemblies) but you could do that, and just clean the optical elements and replace them in the cell.

Otherwise, with the optics out, you can warm and extract the frozen screws as I've described. How many of these radial screws are being obstinate? Do you reckon they've been threadlocked in place? If so, the usual method of removing fasteners bonded with acrylic glues is to carefully heat the joint to 200C which softens the glue enough to break out the screw. A flame cannot be used due to the tube paint. But a soldering iron on the screw head might do the trick...

[Gina]

I would prefer not to disturb the setting of the lens within the cell.  5 of the 6 radial screws won't budge, the other came out quite easily.  There was no sign of anything locking it.  I think the rest are corroded in.  I think I'll make do with just cleaning the lens.  Having found there wasn't actually any damage, I don't want to cause any myself!!

[tonyowens_uk]

Sounds good Gina. That will get the scope back running by the shortest route.

Best  Tony