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

Nippon Kogaku - 65mm - An advice on how to clean or refurbish it?

  • Please log in to reply
46 replies to this topic

#26 wfj

wfj

    Surveyor 1

  • *****
  • Posts: 1568
  • Joined: 10 Jan 2008
  • Loc: California, Santa Cruz County

Posted 29 October 2018 - 10:10 PM

By the way, does anyone know if it would be okay to use a fine grit sandpaper and some oil to remove rust on the telescope and tripod? Maybe some light sanding and mineral oil or teak oil on the wooden case and tripod legs? The wood appears to have a very thin grain, and I thought I read somewhere that it is a teak case. 

 

The enamel is thin. If you have a "browning" spot, don't rub it out because that's actually the brass showing through very thin enamel. You'll just get a bigger brown spot.
 



#27 Dave Trott

Dave Trott

    Mariner 2

  • *****
  • Posts: 244
  • Joined: 30 Dec 2009
  • Loc: Colorado

Posted 29 October 2018 - 10:23 PM

It looks like you have many important accessories. The little reflex finder is quite unique to this scope. To see it in action check out my video: https://www.youtube....4xsZICqPNY&t=6s. The clamp-on finder was an option with these scopes so it is not "missing" from your outfit.

- Dave


  • rolo, Bomber Bob and bdaniele79 like this

#28 quantum_spintronic

quantum_spintronic

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 29 Oct 2018

Posted 30 October 2018 - 09:44 AM

That objective definitely needs cleaning and they are tricky. I don't think there's a way to remove it without first removing the dew shield and then the complete cell. I had to remove the cell,three collimation screws that hold it place. It will probably need to be collimated(aligned) afterwards so if you don't have the tool it may be off.

I had one recently and I had to clean it, the views were excellent. In that condition the value is greatly diminished.

 

Here's the link to my post on this scope. It may be helpful to you.

 

https://www.cloudyni...-nippon-kogaku/

 

Rolo

Rolo,

 

Great post, I read through the whole thing. I have a couple questions, if you don't mind. Do you think it is worth it to buy a collimator and try to clean the lens myself? Also, I saw in your post that you used a Takahashi eyepiece with your scope. Would any 1.25in eyepiece work with this telescope?



#29 quantum_spintronic

quantum_spintronic

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 29 Oct 2018

Posted 30 October 2018 - 09:47 AM

The enamel is thin. If you have a "browning" spot, don't rub it out because that's actually the brass showing through very thin enamel. You'll just get a bigger brown spot.
 

Do you mean a browning spot on the chrome? What do you suggest as the best way to clean the chrome/metal to prevent rust from spreading?

 

It looks like you have many important accessories. The little reflex finder is quite unique to this scope. To see it in action check out my video: https://www.youtube....4xsZICqPNY&t=6s. The clamp-on finder was an option with these scopes so it is not "missing" from your outfit.

- Dave

Dave, I watched your video. That little finder is pretty neat. So the finder was not an included part of the kit? Do you know what all would have been included in the normal kit, or what might be missing? I know I am missing the fine tuning knob, and I think the eyepiece used for projecting an image of the sun. Do you know where I might be able to get parts, or is it just luck in finding something on ebay?



#30 Dave Trott

Dave Trott

    Mariner 2

  • *****
  • Posts: 244
  • Joined: 30 Dec 2009
  • Loc: Colorado

Posted 30 October 2018 - 11:02 AM

The brochure you have in one of your pictures will list the "normal" accessories and the clamp-on finder will be mentioned as a option number 2. I think you have the complete set of eyepieces but you may be missing the sun filter. You don't ever want to actually use the sun filter anyway ( see https://www.cloudyni...ce-sun-filters/ ) but it is nice to have it to make the outfit 100 percent complete. It's also nice to have the clamp-on finder but it is an add-on.

- Dave


  • Bomber Bob likes this

#31 wfj

wfj

    Surveyor 1

  • *****
  • Posts: 1568
  • Joined: 10 Jan 2008
  • Loc: California, Santa Cruz County

Posted 30 October 2018 - 11:57 AM

Do you mean a browning spot on the chrome? What do you suggest as the best way to clean the chrome/metal to prevent rust from spreading?

Meant the white enamel on the tube. For spots on it you have to clean and “feather” in white appliance paint.

 

For rust on chrome rub the dull side of cooking aluminum foil. Creates a combustive process similar to thermite to “burn” away rust.



#32 rolo

rolo

    Cosmos

  • *****
  • Posts: 7677
  • Joined: 14 Jan 2007
  • Loc: GA

Posted 30 October 2018 - 12:20 PM

Rolo,

 

Great post, I read through the whole thing. I have a couple questions, if you don't mind. Do you think it is worth it to buy a collimator and try to clean the lens myself? Also, I saw in your post that you used a Takahashi eyepiece with your scope. Would any 1.25in eyepiece work with this telescope?

I had a difficult time getting 1.25" eyepieces to reach focus, some would most wouldn't .The Takahashi tool is expensive so I wouldn't recommend buying it just for that scope. There are cheaper Cheshier eyepiece that you can use but it may be difficult for a begginer to understand the process and the push pull collimation screws.Maybe someone at your local Astronomy club can help. 


  • wfj likes this

#33 wfj

wfj

    Surveyor 1

  • *****
  • Posts: 1568
  • Joined: 10 Jan 2008
  • Loc: California, Santa Cruz County

Posted 30 October 2018 - 03:00 PM

Look on my thread for handling 1.25 EPs. Use a normal diagonal with a long filter holder to act as a reducer for the 36mm focuser diameter down to 33.6mm standard. You can then also unscrew the 40mm from the erector and slide in a standard 1.25 barrel and use that in the standard diagonal for excellent low power views.


Edited by wfj, 30 October 2018 - 09:45 PM.


#34 quantum_spintronic

quantum_spintronic

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 29 Oct 2018

Posted 31 October 2018 - 10:03 AM

The brochure you have in one of your pictures will list the "normal" accessories and the clamp-on finder will be mentioned as a option number 2. I think you have the complete set of eyepieces but you may be missing the sun filter. You don't ever want to actually use the sun filter anyway ( see https://www.cloudyni...ce-sun-filters/ ) but it is nice to have it to make the outfit 100 percent complete. It's also nice to have the clamp-on finder but it is an add-on.

- Dave

Dave, gotcha. I did look through catalog that came in the box. It would be nice to have the finder, but it isn't that big of a deal. I used the little prism on the eyepiece last night, and it didn't work half bad.

 

I had a difficult time getting 1.25" eyepieces to reach focus, some would most wouldn't .The Takahashi tool is expensive so I wouldn't recommend buying it just for that scope. There are cheaper Cheshier eyepiece that you can use but it may be difficult for a begginer to understand the process and the push pull collimation screws.Maybe someone at your local Astronomy club can help. 

Rolo, I'll have to look around for a local astronomy club. I'm not in a high density area, so I may have to travel a bit. The cheshire collomitor is the one I was looking at purchasing. They look pretty cheap. By the way, how did you get the resin or glue off of the screws to remove the lens?

 

Look on my thread for handling 1.25 EPs. Use a normal diagonal with a long filter holder to act as a reducer for the 36mm focuser diameter down to 33.6mm standard. You can then also unscrew the 40mm from the erector and slide in a standard 1.25 barrel and use that in the standard diagonal for excellent low power views.

Would I be able to mount a camera if I were to use a reducer? I have a Nikon D7100 that would be nice to use with a telescope. Also, when using the scope last night, the focuser kept moving. Is there a way to tighten it?


Edited by quantum_spintronic, 31 October 2018 - 10:13 AM.


#35 quantum_spintronic

quantum_spintronic

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 29 Oct 2018

Posted 31 October 2018 - 10:12 AM

Looks like classic mold all over the lenses.  Get expert advice on how to clean it.   Do not try and rub it off.   

 

The problem with taking out the lenses to clean is that it's easy to chip the lenses, especially the flint (inner) one.  One can unscrew the dewcap tube in front of the lens if you wish to halt the growth of any mold (a few hours exposure to the sun can helpt with that without harm.

 

The cell is a temperature compensating one with little "fingers" that can be bent or broken by accident. Not the best scope to learn how to clean lenses with.

 

Mine had a similar appearance, and it turned out to not be mold but smoke residue that comes off with a few drops of Dawn in a bowel of water. But I used it for years w/o cleaning it. Suggest you let it be for the moment.

So, I emailed a telescope company near me, and they informed me that based on the pictures, the coating may or may not be ruined. Their take on it was that paying them to just clean the lens would be expensive and may not fix the problem completely. Having the company to do it the right way would end up costing more than the telescope was worth. They advised that I look for an astronomy club, and try to do the cleaning with some help.



#36 Garyth64

Garyth64

    Mercury-Atlas

  • *****
  • Posts: 2926
  • Joined: 07 May 2015
  • Loc: SE Michigan

Posted 31 October 2018 - 12:29 PM

Hmm, some thoughts:

 

What was the name of the company?

 

If a lens is sent out to be coated, doesn't it get cleaned first?

 

I think a lens can be recoated, or isn't that a good idea.

 

EDIT:  I'm thinking of maybe having my 5" Apogee lens cleaned and recoated.


Edited by Garyth64, 31 October 2018 - 01:55 PM.


#37 starman876

starman876

    Hubble

  • *****
  • Posts: 17958
  • Joined: 28 Apr 2008
  • Loc: VA

Posted 31 October 2018 - 01:44 PM

So, I emailed a telescope company near me, and they informed me that based on the pictures, the coating may or may not be ruined. Their take on it was that paying them to just clean the lens would be expensive and may not fix the problem completely. Having the company to do it the right way would end up costing more than the telescope was worth. They advised that I look for an astronomy club, and try to do the cleaning with some help.

Where are you located. 



#38 DAVIDG

DAVIDG

    Cosmos

  • *****
  • Posts: 8266
  • Joined: 02 Dec 2004
  • Loc: Hockessin, De

Posted 31 October 2018 - 02:24 PM

Hmm, some thoughts:

 

What was the name of the company?

 

If a lens is sent out to be coated, doesn't it get cleaned first?

 

I think a lens can be recoated, or isn't that a good idea.

 

EDIT:  I'm thinking of maybe having my 5" Apogee lens cleaned and recoated.

 Majestic Optical coating does  MgF2 AR coating on lenses but they don't strip the old coating off. You have to do that. 

https://www.majestic...tings.html#MGF2

 

          - Dave 


  • Garyth64 likes this

#39 Garyth64

Garyth64

    Mercury-Atlas

  • *****
  • Posts: 2926
  • Joined: 07 May 2015
  • Loc: SE Michigan

Posted 31 October 2018 - 02:43 PM

 Majestic Optical coating does  MgF2 AR coating on lenses but they don't strip the old coating off. You have to do that. 

https://www.majestic...tings.html#MGF2

 

          - Dave 

Thanks Dave.  I've had Majestic do all of my mirrors, I guess I didn't look any further into the website.

I'll wait for them to get relocated and make contact.



#40 quantum_spintronic

quantum_spintronic

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 29 Oct 2018

Posted 31 October 2018 - 02:59 PM

Hmm, some thoughts:

 

What was the name of the company?

 

If a lens is sent out to be coated, doesn't it get cleaned first?

 

I think a lens can be recoated, or isn't that a good idea.

 

EDIT:  I'm thinking of maybe having my 5" Apogee lens cleaned and recoated.

The person I emailed was Martin Cohen with C7 in the Baltimore-Washington metro area. His answer was twofold. First, based on the images I sent, the anti reflective coating is likely stained, and the glass may even be etched by the mold. Additionally, cleaning the lens may not solve the mold problem long term unless the entire telescope was treated. Two, his company is geared towards professional equipment, and is expensive for amateur astronomers. In general, he didn't see the point in paying to have the lens professionally cleaned if there was potential for the glass to be etched and if it may not solve the mold problem. He didn't seem to think the lens and scope were beyond repair, just that it didn't make sense to pay someone to do it when someone with a little more knowledge could do an okay job.

 

I may have better luck with another company, but quick google searches aren't giving me any hits closer than his shop in MD.

 

Where are you located. 

I'm on Delmarva.


Edited by quantum_spintronic, 31 October 2018 - 03:01 PM.

  • Garyth64 likes this

#41 starman876

starman876

    Hubble

  • *****
  • Posts: 17958
  • Joined: 28 Apr 2008
  • Loc: VA

Posted 31 October 2018 - 03:18 PM

The person I emailed was Martin Cohen with C7 in the Baltimore-Washington metro area. His answer was twofold. First, based on the images I sent, the anti reflective coating is likely stained, and the glass may even be etched by the mold. Additionally, cleaning the lens may not solve the mold problem long term unless the entire telescope was treated. Two, his company is geared towards professional equipment, and is expensive for amateur astronomers. In general, he didn't see the point in paying to have the lens professionally cleaned if there was potential for the glass to be etched and if it may not solve the mold problem. He didn't seem to think the lens and scope were beyond repair, just that it didn't make sense to pay someone to do it when someone with a little more knowledge could do an okay job.

 

I may have better luck with another company, but quick google searches aren't giving me any hits closer than his shop in MD.

 

I'm on Delmarva.

So you are not far from Rehobeth beach in DE?



#42 quantum_spintronic

quantum_spintronic

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 29 Oct 2018

Posted 31 October 2018 - 03:30 PM

So you are not far from Rehobeth beach in DE?


I was in Rehoboth over the weekend for the Sea Witch festival.

#43 starman876

starman876

    Hubble

  • *****
  • Posts: 17958
  • Joined: 28 Apr 2008
  • Loc: VA

Posted 31 October 2018 - 05:19 PM

You can try Cumberland optics in MD.  They make the optics for Questar.  Maybe they would clean it at a reasonable price.



#44 wfj

wfj

    Surveyor 1

  • *****
  • Posts: 1568
  • Joined: 10 Jan 2008
  • Loc: California, Santa Cruz County

Posted 31 October 2018 - 09:30 PM

Probably what was meant was that the coating could be damaged (potentially). They really can’t tell until they clean it.

 

The Nikon coatings are very durable so I’m wary of this. Also, old glass does not hold up to recoating - tends to shatter.

 

You need to find someone who handles this kind of thing that you can drop by and get an assessment.

 

As to a focal reducer for digital photography, I’ll look into that. You can get a DSLR to reach focus just fine. But a .3x focal reducer might not work with the stock focuser.



#45 strdst

strdst

    Aurora

  • *****
  • Posts: 4855
  • Joined: 23 Mar 2008
  • Loc: Oregon Territory

Posted 01 November 2018 - 03:11 AM

Hi Q.S.

 

I thought I'd wait to post until you had gotten all the good advice and then give you minelol.gif

 

I bought one of these rare Nippon Kogaku 6.5 CM scopes in 2010. Certainly a quite sought after telescope. I did a lot of  "soughting" after that first purchase and now have...uh... 5. Hardly rare in my house but in the bigger picture probably. They appear on eBay once or twice a year. Sometimes without the mount and tripod. 

 

My best condition/complete telescope and kit is # 2978. It is the exact kit as yours with the 6 eyepieces. The export tag is dated Nov. 14, 1956. I paid by far the most for that scope. Not understanding how reserve bidding works I put in my worst case scenario bid on eBay. I think the auction had a few days to run and was at like $500. To prepare for the inevitable snipe I typed in $2000 and "ding ding ding" I met the reserve which meant even if no-one bid against me I was in for 2K! And no one bid against mefrown.gif Oh and then there was the shipping costs! My other less complete kits came in for about $1000 each through Craigslist postings. I'm sure they are worth less as I'm always willing to pay too much for things I really want.

 

That first Nippon Kogaku 6.5 was acquired through an eBay auction. I picked it up in WA. It had been stored at a work site. The work site was a gravel crushing/concrete production plant. The lens, well, I couldn't see anything resembling glass when I looked in. The first views were full of diffusion as the light scattered through the "dust" coat. I posted asking for advice just as you did here on CN. A most prominent member at the time and fearless Nippon Kogaku afficianado Clint Caveman Whitman offered to clean the glass for me. He did a fantastic job. 

 

You are smart to be asking questions and considering using the telescope as is. As others have said there are risks inherent in removing the lens elements. None of my Nippon Kogaku telescopes exhibit centered "Newton's Rings" indicating that the foil spacers are uneven in thickness. Maybe the optics would be better if the lens elements were separated and new foil was installed but I've chipped too much glass over the last 50+ years to do that myself. I'm sorta fine working with Unitron, Swift, Royal Astro glass but not Nippon Kogaku nor Goto Kogaku, nor Takahashi. Some folks here are fearless and steady handed, I'm not. 

 

To that end I have sent a few lenses to Barry at D&G Optical. There was a time when he would clean and re-spacer and even collimate if you sent him the whole optical tube for a very reasonable price. I'm not sure if that is a service he now performs. D&G is in PA. 

 

I have had a few lenses where the coating had gone south on the crown or sky side element. I soaked them in warm sulfuric acid for a few days and the rest of the coating dissolved leaving a clear lens. These were Swift lenses. Easy to remove from the metal cell unlike Nippon Kogaku. Don't do this to the flint (eyepiece side) element as they are different glass types and the acid will harm the glass, I've read.

 

So my advice. Use the telescope as is. Treasure it as it has family history. If you think the views are being impacted by spurious light consider having the glass cleaned if you can find a lab or fearless individual here. If you do it yourself be very careful and good luck to you.

 

The Nippon Kogaku .965 eyepieces are very fine. The 7mm and 9mm Orthoscopics are divine. The 18mm H and 25mm H are exquisite. The 5mm O offers too much magnification for my seeing conditions. The 12.5 H is a good eyepiece as well but such a tiny hole to look through!  

 

I have wiped down the legs of these telescopes with Murphy's Oil Soap and they respond well. Others here have their favorite waxes and cleaners. 

 

I see Samhain ended. Time to let the bonfire die down and start observing again. Looks safe out here... Good night.


  • wfj, terraclarke, Bomber Bob and 1 other like this

#46 Bomber Bob

Bomber Bob

    Voyager 1

  • *****
  • Posts: 13993
  • Joined: 09 Jul 2013
  • Loc: The Deep South, USA

Posted 01 November 2018 - 06:16 AM

So my advice. Use the telescope as is. Treasure it as it has family history. If you think the views are being impacted by spurious light consider having the glass cleaned if you can find a lab or fearless individual here. If you do it yourself be very careful and good luck to you.

 

Great advice.  If you don't want to try cleaning the lens yourself, Ol' Bomber Bob has cleaned many lenses for CN Members, along with my own Classics -- including the Goto contact-doublet and even the corrector & mirrors of my 1958 Questar.  The biggest risk is shipping rare optics back & forth.

 

If you decide to clean the lens yourself, you'll get lots of help from this Community.



#47 quantum_spintronic

quantum_spintronic

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 29 Oct 2018

Posted 05 November 2018 - 10:06 AM

You can try Cumberland optics in MD.  They make the optics for Questar.  Maybe they would clean it at a reasonable price.

 

I may give them a call. I have an uncle that lives up that way, and my parents regularly go out there. Thanks for the heads up.

 

Hi Q.S.

 

I thought I'd wait to post until you had gotten all the good advice and then give you minelol.gif

 

I bought one of these rare Nippon Kogaku 6.5 CM scopes in 2010. Certainly a quite sought after telescope. I did a lot of  "soughting" after that first purchase and now have...uh... 5. Hardly rare in my house but in the bigger picture probably. They appear on eBay once or twice a year. Sometimes without the mount and tripod. 

 

My best condition/complete telescope and kit is # 2978. It is the exact kit as yours with the 6 eyepieces. The export tag is dated Nov. 14, 1956. I paid by far the most for that scope. Not understanding how reserve bidding works I put in my worst case scenario bid on eBay. I think the auction had a few days to run and was at like $500. To prepare for the inevitable snipe I typed in $2000 and "ding ding ding" I met the reserve which meant even if no-one bid against me I was in for 2K! And no one bid against mefrown.gif Oh and then there was the shipping costs! My other less complete kits came in for about $1000 each through Craigslist postings. I'm sure they are worth less as I'm always willing to pay too much for things I really want.

 

That first Nippon Kogaku 6.5 was acquired through an eBay auction. I picked it up in WA. It had been stored at a work site. The work site was a gravel crushing/concrete production plant. The lens, well, I couldn't see anything resembling glass when I looked in. The first views were full of diffusion as the light scattered through the "dust" coat. I posted asking for advice just as you did here on CN. A most prominent member at the time and fearless Nippon Kogaku afficianado Clint Caveman Whitman offered to clean the glass for me. He did a fantastic job. 

 

You are smart to be asking questions and considering using the telescope as is. As others have said there are risks inherent in removing the lens elements. None of my Nippon Kogaku telescopes exhibit centered "Newton's Rings" indicating that the foil spacers are uneven in thickness. Maybe the optics would be better if the lens elements were separated and new foil was installed but I've chipped too much glass over the last 50+ years to do that myself. I'm sorta fine working with Unitron, Swift, Royal Astro glass but not Nippon Kogaku nor Goto Kogaku, nor Takahashi. Some folks here are fearless and steady handed, I'm not. 

 

To that end I have sent a few lenses to Barry at D&G Optical. There was a time when he would clean and re-spacer and even collimate if you sent him the whole optical tube for a very reasonable price. I'm not sure if that is a service he now performs. D&G is in PA. 

 

I have had a few lenses where the coating had gone south on the crown or sky side element. I soaked them in warm sulfuric acid for a few days and the rest of the coating dissolved leaving a clear lens. These were Swift lenses. Easy to remove from the metal cell unlike Nippon Kogaku. Don't do this to the flint (eyepiece side) element as they are different glass types and the acid will harm the glass, I've read.

 

So my advice. Use the telescope as is. Treasure it as it has family history. If you think the views are being impacted by spurious light consider having the glass cleaned if you can find a lab or fearless individual here. If you do it yourself be very careful and good luck to you.

 

The Nippon Kogaku .965 eyepieces are very fine. The 7mm and 9mm Orthoscopics are divine. The 18mm H and 25mm H are exquisite. The 5mm O offers too much magnification for my seeing conditions. The 12.5 H is a good eyepiece as well but such a tiny hole to look through!  

 

I have wiped down the legs of these telescopes with Murphy's Oil Soap and they respond well. Others here have their favorite waxes and cleaners. 

 

I see Samhain ended. Time to let the bonfire die down and start observing again. Looks safe out here... Good night.

strdst, thanks for the reply. I'm going to check out D&G, it looks like they're not too far away if I need to have the lens professionally cleaned. Also, I will definitely be keeping the old nippon. It's a nice piece of family history. The fact that my great uncle, who worked as an astronomer for the Naval Research Laboratory, as well as my grandmother, grandfather, aunts, uncles and other extended family have all used this telescope to look out to the stars, planets and moon is kind of enchanting. The fact that my kids, and maybe some day my own grandchildren, will also be able to look out through the same glass is also a great reason to keep it.

 

So my advice. Use the telescope as is. Treasure it as it has family history. If you think the views are being impacted by spurious light consider having the glass cleaned if you can find a lab or fearless individual here. If you do it yourself be very careful and good luck to you.

 

Great advice.  If you don't want to try cleaning the lens yourself, Ol' Bomber Bob has cleaned many lenses for CN Members, along with my own Classics -- including the Goto contact-doublet and even the corrector & mirrors of my 1958 Questar.  The biggest risk is shipping rare optics back & forth.

 

If you decide to clean the lens yourself, you'll get lots of help from this Community.

Bob, thank you for the offer. I think I'm going to do as much light cleaning as I can to get rid of the dust/debris, and then leave as is for now. Taking out the old telescope has renewed my interest in astronomy, and I might end up purchasing a larger newtonian telescope until I get a chance to have the nippon cleaned well. I have two young kids, and while they're a little young now, I think they'll appreciate keeping the scope around when they're older.


  • wfj, terraclarke and Ben Bajorek 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