#1  
Old 21-02-2009, 03:14 PM
strongmanmike's Avatar
strongmanmike (Michael)
Woohoo it's clear

strongmanmike is offline
 
Join Date: May 2006
Location: Canberra
Posts: 14,749
Nervous lens cleaning

After 14 years I thought it was time to clean away the junk that had accumulated on the inside face of the objective in my AP 152EDF Starfire. I have tended to store the scope in the upright position for the last few years so any dust or crap that has managed to get in the tube in that time had settled on the inside face of the lens cell. While not bad it wa just time to get rid of it.

I had been nervous about this for a while and didn't have the correct allen wrench to remove the lens cell screws but today I went to the hardware store and grabed the 7/64 wrench I needed (had to buy a whole set though).

Taking out a piece of high precission glass worth several thousand dollars is pretty nerve racking I must say and I had a few beads of sweat running down my cheek.

I first blew off any loose dust and then brushed the glass surface gently with a soft Wooster brush. I used an isoproyl alcohol mix, originally formulated by Dr Clay Sherrod in the US and sold by OPT in California. I used pure cotton swabs to gently clean the glass with the solution.

The Dr Clay solution is a mix of Distilled water, pure isoproyl alcohol, Photo-Flo and Windex.

The process went well and the objective looks like new - clean both inside and out now.

Such a rare event required some photos of course

http://www.pbase.com/strongmanmike2002/6_inch_baby

Mike
Reply With Quote
  #2  
Old 21-02-2009, 04:01 PM
h0ughy's Avatar
h0ughy (David)
DOGHOUSE REBORN

h0ughy is offline
 
Join Date: Apr 2005
Location: NEWCASTLE NSW Australia
Posts: 30,683
hope you wore a mask and gloves, and an operation smock
Reply With Quote
  #3  
Old 21-02-2009, 05:00 PM
strongmanmike's Avatar
strongmanmike (Michael)
Woohoo it's clear

strongmanmike is offline
 
Join Date: May 2006
Location: Canberra
Posts: 14,749
Quote:
Originally Posted by h0ughy View Post
hope you wore a mask and gloves, and an operation smock
No but there was a period there where I didn't breath for a few minutes
Reply With Quote
  #4  
Old 21-02-2009, 07:10 PM
h0ughy's Avatar
h0ughy (David)
DOGHOUSE REBORN

h0ughy is offline
 
Join Date: Apr 2005
Location: NEWCASTLE NSW Australia
Posts: 30,683
Quote:
Originally Posted by strongmanmike View Post
No but there was a period there where I didn't breath for a few minutes
aha so the pulse was there
Reply With Quote
  #5  
Old 21-02-2009, 07:23 PM
leon's Avatar
leon
Registered User

leon is offline
 
Join Date: Apr 2006
Location: ballarat
Posts: 10,824
Know the feeling Mike, I actually caused myself a head ache and held my breath for long periods whilst I replaced the filter in front of the Canon 5D's sensor.

Scary stuff, but now that i had done it a couple of times it was much easier second time round.

Leon
Reply With Quote
  #6  
Old 21-02-2009, 07:26 PM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 10,900
Hey Mike

Nerves of steel from the man of steel – top job; I’m sure glad that the whole process went so smoothly, with such a positive outcome.

Truly a case of nothing ventured, nothing gained!

Cheers

Dennis
Reply With Quote
  #7  
Old 21-02-2009, 08:46 PM
spearo's Avatar
spearo (Frank)
accepts all donations

spearo is offline
 
Join Date: Feb 2006
Location: Braidwood (outskirts)
Posts: 2,280
I think i see a fingerprint on that lens...

no wait, it's my screen...
looks good!

frank
Reply With Quote
  #8  
Old 21-02-2009, 11:47 PM
strongmanmike's Avatar
strongmanmike (Michael)
Woohoo it's clear

strongmanmike is offline
 
Join Date: May 2006
Location: Canberra
Posts: 14,749
Thanks guys

It was an easy thing to do in the end really, the actual lens cell is easily removed by undoing three screws, the main tube end housing was squared at the factory at time of manufacture and this is what sets the front lens cell square and thus collimated, so all that is necessary is to remove the lens cell, clean and replace, collimation is unaffected (hopefully?) Roland Christien assured me so I believe him since he made it...but I'll be happier once I see those tiny perfectly focused dots on my screen

Tomorrow?...install the Astronomik narrow band filter set, giving me L R G B Ha SII OIII in my 7 position filterwheel, stay tuned I have the HBetta too but it won't fit in the wheel unless I remove a filter

Mike
Reply With Quote
  #9  
Old 22-02-2009, 09:49 AM
Tilt's Avatar
Tilt (Michael)
Registered User

Tilt is offline
 
Join Date: Jan 2008
Location: Canberra
Posts: 548
Woah! I bet that was uber scary.

Nice work, I just love good glass.

Michael
Reply With Quote
  #10  
Old 22-02-2009, 11:32 AM
Quark's Avatar
Quark (Trevor)
Registered User

Quark is offline
 
Join Date: Apr 2008
Location: Broken Hill NSW Australia
Posts: 4,012
Hi Mike,

No doubt a very stressful process but looks like a top job

You mention in your post the cleaning mixture you used, can you clarify whether you acquired the raw materials and mixed it up yourself or if you were able to source the cleaning mixture already mixed.

Regards
Trevor
Reply With Quote
  #11  
Old 22-02-2009, 02:12 PM
strongmanmike's Avatar
strongmanmike (Michael)
Woohoo it's clear

strongmanmike is offline
 
Join Date: May 2006
Location: Canberra
Posts: 14,749
Quote:
Originally Posted by Tilt View Post
Woah! I bet that was uber scary.

Nice work, I just love good glass.

Michael
Ooooooh yeh! 6" of oil spaced priceless triplet magic

Quote:
Originally Posted by Quark View Post
Hi Mike,

No doubt a very stressful process but looks like a top job

You mention in your post the cleaning mixture you used, can you clarify whether you acquired the raw materials and mixed it up yourself or if you were able to source the cleaning mixture already mixed.

Regards
Trevor
Hi Trev

I got it from OPT in kit form back in 2004'ish but it is still available exactly as I purchsed:

http://www.optcorp.com/product.aspx?pid=1952

Was a good bargain when we were at AU$1 = US$0.90c+ but now it'd be about AU$90 delivered I guess? Still an excellent product and lasts a long time, I've used it to clean most of my optical components and some a few times and there is still plenty left

Mike
Reply With Quote
  #12  
Old 22-02-2009, 06:47 PM
Geoff45's Avatar
Geoff45 (Geoff)
PI rules

Geoff45 is offline
 
Join Date: Jul 2006
Location: Sydney
Posts: 2,414
You could try windex and a tissue! Quote from Al Nagler " If the eyepiece or objective lens has particles stuck to it that can't be blown off, moisten (do not soak) a tissue with Windex and gently blot the surface, without rubbing."
See here for more details.
Geoff
Reply With Quote
  #13  
Old 22-02-2009, 07:21 PM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 10,900
Quote:
Originally Posted by ghsmith45 View Post
You could try windex and a tissue!
Geoff
I understand that some recipes of Windex may contain ammonia as an ingredient and from what I have read, ammonia should not be used for cleaning coated optics.

Some time ago, in a previous post about cleaning LCD’s, I was advised not to use Windex on my LCD screen, due to its ammonia content.

It seems there may be Windex sans Ammonia and Windex with Ammonia?

Cheers

Dennis
Reply With Quote
  #14  
Old 22-02-2009, 08:49 PM
avandonk's Avatar
avandonk
avandonk

avandonk is offline
 
Join Date: Aug 2005
Location: Melbourne
Posts: 4,786
It depends on what is contaminating your optical surfaces. Isopropyl Alcohol is great for only one good reason, it's rate of evaporation is such that there is no condensation of nasties from the atmosphere as is produced by ethyl or methyl. The rate of the evaporating isopropyl is such that it's evaporating cloud shields the surface from condensation due to evaporative cooling.

To remove non polar nasties analytical quality petroleum ether is good. A very dilute non ionic detergent such as Teepol is also good. These should be very gently cycled until all residue is removed.

The anti reflection coatings on your optics are porous at a molecular level to the contaminants that really take hold. Only the best methods of coating can minimise this porousity. RF ion bombardment coating helps.

Unless you know what you are doing do not do it. Get advice.

Sometimes even a tiny bit of caustic in a cleaning solution is better than repeated attempts that cause physical (abrasive) damage to the AR coatings. The AR coating is unaffected by weak caustic solutions. It is the bond between the glass and the AR coating that is damaged as any caustic solution will dissolve glass at the molecular level at the glass AR coating surface interface! This of course will vary by how much Sodium is in the glass. Yes sodium silicate is soluble in even a mild caustic solution. Remember those 'tree gardens'.

After all that, I bet Mike is glad he has already done it! He used a tried and true method.

I have found one of the stickyest contaminants is a vapour or micro drops? That comes from gum trees.

I have had all sorts of contaminants on my 300mm lens including a very big deposit left by a magpie just after dawn. There is no point having good optics if you dont use them. The cunning design of the canon 300mm lens is that the front element is a flat and is 'relatively' cheap to replace. It does the same job as a UV filter.

Sorry for the rave. I have had too many cough medicines .

Bert
Reply With Quote
  #15  
Old 22-02-2009, 09:45 PM
renormalised's Avatar
renormalised (Carl)
No More Infinities

renormalised is offline
 
Join Date: Apr 2008
Location: Townsville
Posts: 9,698
Smile

Quote:
Sorry for the rave. I have had too many cough medicines
Been sampling some of that Isopropyl alcohol, hey Bert

Your "optics" need cleaning
Reply With Quote
  #16  
Old 22-02-2009, 10:41 PM
avandonk's Avatar
avandonk
avandonk

avandonk is offline
 
Join Date: Aug 2005
Location: Melbourne
Posts: 4,786
No I was having a go at the former Japanese Minister for Trade who claimed he had too much cough and cold medication.

bert
Reply With Quote
  #17  
Old 22-02-2009, 10:48 PM
renormalised's Avatar
renormalised (Carl)
No More Infinities

renormalised is offline
 
Join Date: Apr 2008
Location: Townsville
Posts: 9,698
Smile

Quote:
Originally Posted by avandonk View Post
No I was having a go at the former Japanese Minister for Trade who claimed he had too much cough and cold medication.

bert
Probably why he looks so shady....all that alcohol base and he's plastered!!!. Squinting too much
Reply With Quote
  #18  
Old 23-02-2009, 12:18 PM
turbo_pascale's Avatar
turbo_pascale (Rob)
Registered User

turbo_pascale is offline
 
Join Date: Apr 2006
Location: Melbourne, Australia
Posts: 355
Quote:
Originally Posted by strongmanmike View Post
I used an isoproyl alcohol mix, originally formulated by Dr Clay Sherrod in the US and sold by OPT in California. I used pure cotton swabs to gently clean the glass with the solution.

The Dr Clay solution is a mix of Distilled water, pure isoproyl alcohol, Photo-Flo and Windex.
I believe (I am willing to stand corrected), but you cannot get all the bits you need any longer as some of it is considered prohibited to ship. I was going to buy it a few years ago (via Scopestuff I think), but apparently it all got too hard as it was unclear what would and wouldn't be shipped. Check before you order as it might get all the way to customs and then get turned back. Mike I think may have been lucky.


Quote:
Originally Posted by Quark View Post
You mention in your post the cleaning mixture you used, can you clarify whether you acquired the raw materials and mixed it up yourself or if you were able to source the cleaning mixture already mixed.
I am lead to believe when I enquired (again, I'll stand corrected), but the UHTC Cleaning solution that Bintel sells is made to the same formula.

I have a bottle of the stuff sitting on my shelf, unopened. I reviewed how dirty the corrector was, and then decided against it. I think it might be getting time though...

Turbo
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 06:29 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Lunatico Astronomical
Advertisement
Celestron Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
Meade Australia
Advertisement
Astromechanics
Advertisement
SkyWatcher Australia
Advertisement
Astronomy and Electronics Centre
Advertisement