| lipman |
| (member) |
| 07/01/09 05:32 PM |
Problem with cleaning a barlow
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I got a finger mark on my barlow lens, and attempted to use the Orion cleaning kit to remove the mark. I followed the instructions - put a couple of drops of cleaning solution on one of the lens tissues, wiped the lens very carefully, and then dried with a dry lens tissue. Result - horrendous streaking across the entire lens surface. I tried the same thing again, but same result.
I then tried wiping gently with the cleaning cloth - but the streaks remain.
Did I do something wrong here - or is the Orion kit at fault? Either way - I would appreciate advice on how to remedy this situation!
Thanks,
Paul
| Mike Hosea |
| (Post Laureate) |
| 07/01/09 07:21 PM |
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Re: Problem with cleaning a barlow
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Paul, I do it this way, with Q-tips:
http://www.televue.com/engine/page.asp?ID=143
You can try various solvents, including the Orion lens cleaning fluid, water, acetone, alcohol, etc.
| gnowellsct |
| (professor emeritus) |
| 07/02/09 02:51 PM |
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Re: Problem with cleaning a barlow
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I've used Dr. Clay's solution, windex, alcohol, and acetone. The best is Purosol.
The problem with many of these solutions is that (a) they have water in them, which tends to streak; or (b) they are hydrophilic, meaning, like acetone, they suck water right out of the air and then leave a streak on the glass.
Purosol link
I buy them two at a time to reduce shipping cost per bottle, a bottle lasts me over a year. You can get additional information on the astro-physics web site which sells Purosol as part of its kit. Purosol works so well I've never needed the rest of the kit.
regards
Greg N
| lipman |
| (member) |
| 07/02/09 05:11 PM |
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Re: Problem with cleaning a barlow
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Thanks Greg - I'll try Purosol. I've also heard good things about ROR.
Cheers,
Paul
| gnowellsct |
| (professor emeritus) |
| 07/03/09 10:45 AM |
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Re: Problem with cleaning a barlow
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Yes I've heard of ROR and was going to invest in it but, the reason I've tried all the other options is I was never happy with them. My search point stopped with Purosol because my results have been excellent.
The Edmund Optical web site has a lot of lens cleaning options including EO's own cleaning solution. I would experiment more but jeeze they really hammer you on shipping. So unless you happen to be in the market for an RKE as well as cleaner, I would buy somewhere else.
good luck,
Greg N
| desertrefugee |
| (Pooh-Bah) |
| 07/03/09 12:53 PM |
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Re: Problem with cleaning a barlow
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The TeleVue site offers the definitive answer.
In particular, note the suggestion of "fogging" with breath after use of the alcohol (or other solvent). I have found this to be THE finishing touch on any optical glass I find in need of attention.
It works extremely well.
| gnowellsct |
| (professor emeritus) |
| 07/03/09 06:51 PM |
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Re: Problem with cleaning a barlow
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Been there, done that, still prefer Purosol. Greg N
| zawijava |
| (sage) |
| 07/03/09 07:53 PM |
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Re: Problem with cleaning a barlow
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Quote:
The TeleVue site offers the definitive answer.
In particular, note the suggestion of "fogging" with breath after use of the alcohol (or other solvent). I have found this to be THE finishing touch on any optical glass I find in need of attention.
It works extremely well.
I wholeheartedly agree, fogging with the breath and wipe off gently with a lint free lens tissue will remove nearly 100% of residue from cleaning fluids. Even Purosol will leave a residue, it's harder to see but it's there but your breath fog will remove it as well. And, as a last resort, for those pesky stubborn spots that just won't lift off....human spit on the end of a clean finger rubbed gently on the spot and 9X out of 10 the spots gone. Then clean that spot again with cleaning fluid followed by breath fog.
Tim
| Luigi |
| (Post Laureate) |
| 07/04/09 08:58 AM |
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Re: Problem with cleaning a barlow
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Decent grade methanol used with lens tissues will not leave streaks. It's very commonly used in the industry for this reason. Simple, cheap, highly effective. To reach down into a recess to clean an optic, fold the lens tissue as many times as necessary to get it to an appropriate size and use plastic forceps to hold it. Place a drop or two of methanol on the folded tissue and gently wipe. When folding the tissue, don't touch it anywhere near the part that will be used for cleaning. Preferably fold it while wearing gloves so as not to transfer oil and salts from you skin to the tissue.
| gnowellsct |
| (professor emeritus) |
| 07/04/09 08:34 PM |
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Re: Problem with cleaning a barlow
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Methanol is hydrophilic like isopropyl alcohol. I suspect that many alcohol formations don't streak in dryer areas but do streak in more humid areas. This partly would account fo or the popularity of alcohol--a confirmed user base that has good results in certain regions. regards Greg N
| Mike Hosea |
| (Post Laureate) |
| 07/04/09 09:25 PM |
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Re: Problem with cleaning a barlow
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What causes streaks is not water but residue. It's important to remove the solvent from the lens before it completely evaporates, regardless of what the solvent is. By definition, the more volatile the solvent, the quicker it evaporates, so your technique needs to be good. If you're having problems with streaks, you're letting the solvent evaporate on the lens, which is going to happen if you wipe it to a thin layer and just leave it. That's why Tele Vue's instructions don't say anything about doing it like that. Most of the cleaning products made for the general public are formulated NOT to evaporate quickly. That way, people who don't even know they need to can usually get it wiped off before it evaporates.