Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Cave Astrola 12.5" Model D

  • Please log in to reply
166 replies to this topic

#51 macdonjh

macdonjh

    Fly Me to the Moon

  • *****
  • Posts: 5,626
  • Joined: 06 Mar 2006

Posted 16 March 2020 - 02:40 PM

Ok, it’s time for the important stuff. Can somebody direct me to the proper method for cleaning the primary mirror. Mine seems to be really dirty. And it has a couple of pits or imperfections in it, is this normal?

The short version is: search the Reflectors forum here for "mirror cleaning" or something similar.  There will be hundreds...

 

Slightly longer:

  • Blow loose junk off with compressed air (blowing with your mouth, using one of those lens bulbs, "canned" air from the computer store)
  • Rinse less loose junk off with running water
  • Use a dilute soap solution to soak what ever is stuck, then use cotton balls to wipe the mirror surface (just push the cotton ball around, using the weight of the cotton with no extra pressure)
  • Rinse with running tap water
  • Rinse with distilled water
  • Place on the edge to drain and dry.  I also blow water drops off the edge, and/ or use the edge of a paper towel to wick the water drops off (touch the water drop with the paper and the water will wick into the paper)

 

At least, that's what I've done with mirrors I can remove from their OTAs.



#52 clamchip

clamchip

    Voyager 1

  • *****
  • Posts: 10,586
  • Joined: 09 Aug 2008
  • Loc: Seattle

Posted 16 March 2020 - 02:45 PM

Anybody know how this comes apart? 60mm Spotter Scope.

attachicon.gifspotter2.jpgattachicon.gifspotter4.jpgattachicon.gifspotter1.jpgattachicon.gifspotter3.jpg

The ends unscrew from the tube.

The objective end will have a tiny set screw locking it's movement you will need to

unscrew.

The eyepiece focuses by turning in/out.

 

Robert


Edited by clamchip, 16 March 2020 - 02:46 PM.


#53 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 16 March 2020 - 10:30 PM

The short version is: search the Reflectors forum here for "mirror cleaning" or something similar.  There will be hundreds...

 

Slightly longer:

  • Blow loose junk off with compressed air (blowing with your mouth, using one of those lens bulbs, "canned" air from the computer store)
  • Rinse less loose junk off with running water
  • Use a dilute soap solution to soak what ever is stuck, then use cotton balls to wipe the mirror surface (just push the cotton ball around, using the weight of the cotton with no extra pressure)
  • Rinse with running tap water
  • Rinse with distilled water
  • Place on the edge to drain and dry.  I also blow water drops off the edge, and/ or use the edge of a paper towel to wick the water drops off (touch the water drop with the paper and the water will wick into the paper)

 

At least, that's what I've done with mirrors I can remove from their OTAs.

 

Thanks, adding some photos.

 

Attached Thumbnails

  • FB4E7715-7CC8-4441-AFC3-883421F74F74.jpeg
  • DD5F0C42-8ED2-42E3-89DC-F4196DC0E431.jpeg
  • 579D481F-3755-4B5A-BFDA-C8E69C72DF28.jpeg

  • Bomber Bob and ANKry like this

#54 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 16 March 2020 - 10:33 PM

The ends unscrew from the tube.

The objective end will have a tiny set screw locking it's movement you will need to

unscrew.

The eyepiece focuses by turning in/out.

 

Robert

Thanks, this helps. This way I can actually put a little force into it knowing they unscrew.



#55 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 18 March 2020 - 07:05 AM

Thanks, this helps. This way I can actually put a little force into it knowing they unscrew.

Yes, I used a strap wrench on both ends. Worked really well. Thanks



#56 macdonjh

macdonjh

    Fly Me to the Moon

  • *****
  • Posts: 5,626
  • Joined: 06 Mar 2006

Posted 18 March 2020 - 09:16 AM

attachicon.gif5E8A936B-FC2A-4A22-B6E6-E2DD9745DF6A.jpeg

 

Thanks, adding some photos.

Thanks for the photos, RDFox.  If that was my mirror, I'd start with the steps I outlined.  If is was still dirty the next day after it had dried thoroughly, I'd then step up to using to alcohol and cotton balls (same technique, only the weight of the cotton balls, no additional pressure) since maybe some of that schmutz is fungus.  Alcohol usually leaves streaks for me, so I'd follow the alcohol with acetone.

 

Once you get it at least mostly cleaned off, you can use the "look at a bright light through the mirror" technique to decide if the coatings are in good shape or not.  I've held a mirror such that the sun shone through it and then looked for bright spots in the mirror's shadow on the ground.



#57 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 18 March 2020 - 01:13 PM

Thanks for the photos, RDFox.  If that was my mirror, I'd start with the steps I outlined.  If is was still dirty the next day after it had dried thoroughly, I'd then step up to using to alcohol and cotton balls (same technique, only the weight of the cotton balls, no additional pressure) since maybe some of that schmutz is fungus.  Alcohol usually leaves streaks for me, so I'd follow the alcohol with acetone.

 

Once you get it at least mostly cleaned off, you can use the "look at a bright light through the mirror" technique to decide if the coatings are in good shape or not.  I've held a mirror such that the sun shone through it and then looked for bright spots in the mirror's shadow on the ground.

Thanks, this really helps!



#58 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 19 March 2020 - 11:39 AM

The tubes were gelcoated, not painted, and it was done prior to forming on the mandrel.  Judging by the cracking I see on these, the shop that made these was thinning their gelcoat with acetone instead of styrene monomer.  Cheaper but doesn't allow full polymerization and excessive cracking and shrinkage is the result.

 

You will have to have an automotive paint shop color match the old gelcoat.  Modern whites are much brighter than they were 50 years ago.

Ok, think I’m going to try to put gelcoat on this Tube. Keeping it as close original as possible. I’ll keep you posted as to the progress. I’m still quite a ways from starting on the OTA. I’ve painted several Muscle cars and old Corvettes, but this scares me. I would hate to ruin the tube. And yes you can see the weave through the gelcoat now.



#59 Chuck Hards

Chuck Hards

    You don't know Swift from Astrola

  • *****
  • Posts: 27,405
  • Joined: 03 May 2010

Posted 19 March 2020 - 11:47 AM

You can't really screw up gelcoat, since you can sand-out any runs, drips, etc.  You will be buffing the entire tube and will probably lose the weave print-through.  

 

If you want to preseve that print pattern, I suggest you just do local repairs, then a light priming and automotive paint for a final finish.  That pattern won't keep printing through successive gelcoat layers. 


  • Mr Magoo and Augustus like this

#60 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 20 March 2020 - 11:36 PM

Pier is done.

 

Attached Thumbnails

  • D3421A1B-BF46-4DDF-992E-054655312A3A.jpeg
  • 6CA4C4CF-738A-4427-8CC6-AAB32DAD1AC8.jpeg
  • 69DDAEA4-A41A-495F-A84D-AEFACCD04157.jpeg

  • Joe Bergeron, tim53, L. Regira and 10 others like this

#61 Jeff B

Jeff B

    Fly Me to the Moon

  • *****
  • Posts: 6,810
  • Joined: 30 Dec 2006

Posted 21 March 2020 - 08:14 PM

I see the mirror has a center spot so hopefully the coatings are just filthy.  any luck with the cleaning.  

 

Love the pier!

 

Jeff



#62 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 21 March 2020 - 09:50 PM

I see the mirror has a center spot so hopefully the coatings are just filthy.  any luck with the cleaning.  

 

Love the pier!

 

Jeff

 

Not much luck, it looks like I’m going to send it to get recoated. Put a light behind it and could see quite a bit of it shining through. Argh! But not the end of the world.



#63 Jeff B

Jeff B

    Fly Me to the Moon

  • *****
  • Posts: 6,810
  • Joined: 30 Dec 2006

Posted 22 March 2020 - 09:27 AM

Well, if you're applying fresh paint an grease, why not fresh coatings too!

 

Curious, many times a Newt OTA is stored pointed up, which may be why the primary is so dirty.  But that means the secondary mirror is pointed down and does not get nearly so dirty.  How is the coating on the secondary?  Any scribe marks/writing on the edge of the primary?

 

You are going to have one awesome scope when you're done.

 

Jeff



#64 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 22 March 2020 - 06:49 PM

Well, if you're applying fresh paint an grease, why not fresh coatings too!

 

Curious, many times a Newt OTA is stored pointed up, which may be why the primary is so dirty.  But that means the secondary mirror is pointed down and does not get nearly so dirty.  How is the coating on the secondary?  Any scribe marks/writing on the edge of the primary?

 

You are going to have one awesome scope when you're done.

 

Jeff

I’ve always thought that the heavy end should be stored on the bottom, less chance of falling over. And I always had the top end covered, but as you can see it didn’t do much good. And yes the secondary mirror is cleaner. The primary has a lot of coating missing (light shines through from the bottom). And it does have the date and mirror number scribed on the side 9/24/1967. Another thing, I restore muscle cars and restoring this scope is right up there as being as complicated. And a lot more attention has to be paid to accuracy. You just can’t buff your way to mirror alignment. And this scope will last longer than any car.


  • L. Regira and Jeff B like this

#65 Chuck Hards

Chuck Hards

    You don't know Swift from Astrola

  • *****
  • Posts: 27,405
  • Joined: 03 May 2010

Posted 23 March 2020 - 07:40 AM

The convention is to store Newtonian tubes horizontally, so that the mirror surfaces are approximately vertical.  This keeps dust deposition to a miniumum.  The tube can usually be oriented so that the secondary is also vertical, or upside-down, which accomplishes the same thing.



#66 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 23 March 2020 - 12:08 PM

The convention is to store Newtonian tubes horizontally, so that the mirror surfaces are approximately vertical.  This keeps dust deposition to a miniumum.  The tube can usually be oriented so that the secondary is also vertical, or upside-down, which accomplishes the same thing.

Duh! I didn't think of that. See I'm more challenged than you thought. Thanks. It makes me wonder what other things I'm doing that's not too smart? :)



#67 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 23 March 2020 - 09:50 PM

Updated photos

Attached Thumbnails

  • 554E5597-BE37-4DEB-B1B6-89D3591B45FC.jpeg
  • 01D8415F-FB67-4304-9BAB-7AFAF1489365.jpeg
  • 40714CF9-C41B-42BD-8794-E665BF5E359C.jpeg
  • C2AAAC78-E6CF-4B2D-9950-E9AA974D5732.jpeg

  • Joe Bergeron, tim53, Terra Nova and 1 other like this

#68 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 23 March 2020 - 09:53 PM

Quiz Time! What are these?

Attached Thumbnails

  • E817D8AC-488C-49CC-ACBF-590436BEECAA.jpeg


#69 Chuck Hards

Chuck Hards

    You don't know Swift from Astrola

  • *****
  • Posts: 27,405
  • Joined: 03 May 2010

Posted 23 March 2020 - 10:08 PM

Tube holders.  Nice design!  waytogo.gif

 

Is that foam?


  • TOM KIEHL likes this

#70 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 23 March 2020 - 10:21 PM

Tube holders.  Nice design!  waytogo.gif

 

Is that foam?

Yes it is, I figure I can friction fit them in and seal the ends while I refinish the tube. The plywood will add support for the 3/4” pipe running all the way through it. This way it will rotate and I won’t have to spray upside down, and be just plain easier. BTW the rotating rings were really hard to take off. I’m going to experiment with hot water to expand them and see if it they will slide over new paint, if not I’m going to have to Come up with a different plan. 



#71 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 24 March 2020 - 09:07 PM

Any idea how these small bearings come out? Pressed in? This is a photo of the Dec drive.

Attached Thumbnails

  • 9656F506-BC75-4704-81B8-1443E698914F.jpeg
  • 656699C0-8D16-40F8-B750-362D206A2021.jpeg


#72 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 26 March 2020 - 11:20 AM

These little bearings are pressed in with great care. Ordered new ones (77R6). I’ll keep posting as I go. We’ll see how careful I can be. 



#73 macdonjh

macdonjh

    Fly Me to the Moon

  • *****
  • Posts: 5,626
  • Joined: 06 Mar 2006

Posted 26 March 2020 - 11:31 AM

Duh! I didn't think of that. See I'm more challenged than you thought. Thanks. It makes me wonder what other things I'm doing that's not too smart? smile.gif

What you once lacked in storage knowledge you're making up for in restoration knowledge.  Your mount looks great so far.  You cheated, though: no photos of the head getting cleaned up and painted!  At least it looks like you've cleaned it and painted it, I can see part of it in your photos of your pier.



#74 RDFox

RDFox

    Vostok 1

  • *****
  • topic starter
  • Posts: 100
  • Joined: 04 Jan 2008
  • Loc: Indiana

Posted 26 March 2020 - 04:20 PM

More pics

Attached Thumbnails

  • E9FA12D4-7D7A-4016-A8D4-4664DA30D515.jpeg
  • E99FC814-A4EA-4E9B-B8F4-AEA031B9ABE4.jpeg
  • E6C43880-A61D-48ED-8BE0-B3C3301D0043.jpeg

  • L. Regira, Mr Magoo, Jeff B and 3 others like this

#75 Mr Magoo

Mr Magoo

    Mercury-Atlas

  • *****
  • Posts: 2,761
  • Joined: 05 Nov 2005
  • Loc: Indiana

Posted 26 March 2020 - 07:54 PM

Any idea how these small bearings come out? Pressed in? This is a photo of the Dec drive.

I heated the aluminum block up slightly with a heat gun and they fell right out. 


  • tim53 and RDFox like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics