Re: Lens Cleaner

Christopher Erickson

I really appreciate your report too!


On Fri, Jul 17, 2020 at 5:57 PM Woody Schlom <woody_is@...> wrote:



Well I for one am VERY glad and thankful for your long detailed report.  Yeegads – not what I want happening to any of my scopes.




From: [] On Behalf Of Jerry Floyd
Sent: Friday, July 17, 2020 6:07 PM
Subject: Re: [ap-gto] Lens Cleaner


I don't know whether Rolando will venture an opinion on this off-topic question, but I certainly will.


My William Optics FLT-132 (mounted on an AP1200GTO) is 13 years old and the objective badly needed cleaning.  I tried the standard method - alcohol and cotton balls - and got nowhere.  The flat fields looked as if the objective had been used for target practice.  I ordered a First Contact kit from Photonic Cleaning and, after practicing on magnifying glasses and old binoculars with very satisfactory results, I finally got brave enough to apply it to the refractor.


Big mistake.  The vendor recommends using an O-ring to keep the First Contact polymer fluid away from the rim.  They sell custom-sized O-rings for that purpose and the one I ordered from them seemed to fit well.  Unfortunately, it didn't work.  I applied the fluid to the objective with the scope leveled in the vertical position so it wouldn't run off to one side.  It did anyway, and the O-ring did not prevent the fluid from reaching the rim and penetrating underneath.  When the polymer dried, I lifted it off in accordance with the prescribed procedure (you embed dental floss and/or mesh in the polymer) and the objective looked alright. But when I moved the scope away from the vertical position, the fluid which had leaked over the edge, which as it turned out had not dried, ran down over the back side of the objective, with the result that the stars in all my images are smeared and distorted mercilessly.  In other words, the scope is ruined.  If I could disassemble the scope and take out the objective, I could clean the wayward polymer off the back of the lens, but I have no idea how to do that - it's not straightforward, no screws or anything like that, and since the scope is a triplet there are probably serious ramifications involved in taking it apart and reassembling, recollimating the elements, etc. that I know nothing about.  So I'm looking for an outfit which has the expertise to do that, if it is even feasible, i.e. less expensive than buying a new scope.


So the bottom line is that I don't recommend using this product on expensive telescopes, especially refractors.  Sorry about the long-winded reply to an off-topic question, but I thought it important to prevent someone else from making the mistake that I did.


Jerry L. Floyd 


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