Advice on cleaning microscope optics

[brettpim]

I have a Reichert Zetopan and I recently spent some time cleaning its optical pathway. Things went pretty well overall but I have some questions.

• The top surface of the top lens of my BPK 10X ocular has a spot that did not wipe away, see picture. I am using Foxwest Optical Lens Cleaner Cat. No 1100 with optics cleaning swabs. I am not sure if this spot is a stubborn stain and I should use some other chemical to budge it, or if it is a loss of anti-reflective surface coating.
• I got the optics cleaning swabs in a box that came with my used scope. At some point I will run out. I am assuming that I should **not** use regular coton Q-tips because they might scratch but I wanted to check in case this cheap option is fine to use. If I should **not** use Q-tips, where can I get optics cleaning swabs?
• For stubborn residues stuck to lenses and objectives can I use isopropyl alcohol to clean them off? If not isopropyl alcohol; what "stronger" cleansers can I use if I need more power than the Foxwest Optical Lens Cleaner.
• When I started to disassemble one of my BPK 10x oculars I found that the metal ring which held the very first lens was stuck fast to the ocular's tube which means I cannot access the lenses beneath it for cleaning. What are my options to try to get it moving again? I cannot tell if someone in the microscope's past glued it or if it is just grime that has cemented it? If it is just grime, can I use isopropyl alcohol to try to soften the grime?

[Gatorengineer64]

My tried and true for stubborn camera lenses was always Butane, but it hasn't been as effective on Microscope optics.... but I would still give it a shot....doesn't look like coating loss which tends to look more like a rub

[ClassMSpecie]

Try to look under a microscope at max mag to reveal more information. If the surface is not smooth, you may have physical damage. Then it may not be worth refurbishing. There are some bargains that can be had on older eyepieces, so it's no big deal if you happen to damage the lens while refurbishing.

[brettpim]

Is isopropyl alcohol safe to use to clean microscope lenses? Will it damage the lens coatings?

[BramHuntingNematodes]

Not the coatings usually but high concentration isop can melt cements sometimes. A dilute amount in distilled water freq cleans better and is fine to use. Don't apply directly to optics!

[apochronaut]

Isopropyl is good but is not particularly good as a solvent for fats or oils, which form a good portion of residues on older optics. It tends to leave a film. That can be removed with a mixture of IPA, H2O Acetic acid and dish detergent, followed by H2O and IPA as rinse solvents.

The H2O, IPA, CH3COOH, detergent mixture can be adjusted according to the strength of the detergent. I use a mixture of about 50% water+ 25% of 70% IPA plus 25% CH3COOH, so essentially a 17 1/2% IPA, 1 1/4 % Acetic acid aqueous solution plus 6-10 drops clear unscented detergent.
That cocktail cleans most stuff off. Sometimes I have to resort to Ethanol where it is safe to use but not often. Ethanol is not safe on certain enamels, particulatly on objective lettering, on lens cements and on most coatings. With care it can be used on cemented uncoated optics, since it evaporates so quickly.

[brettpim]

Isopropyl is good but is not particularly good as a solvent for fats or oils, which form a good portion of residues on older optics. It tends to leave a film. That can be removed with a mixture of IPA, H2O Acetic acid and dish detergent, followed by H2O and IPA as rinse solvents.

The H2O, IPA, CH3COOH, detergent mixture can be adjusted according to the strength of the detergent. I use a mixture of about 50% water+ 25% of 70% IPA plus 25% CH3COOH, so essentially a 17 1/2% IPA, 1 1/4 % Acetic acid aqueous solution plus 6-10 drops clear unscented detergent.
That cocktail cleans most stuff off. Sometimes I have to resort to Ethanol where it is safe to use but not often. Ethanol is not safe on certain enamels, particulatly on objective lettering, on lens cements and on most coatings. With care it can be used on cemented uncoated optics, since it evaporates so quickly.

I just want to make sure that IPA in the above recipe is isopropyl alcohol?

[apochronaut]

That would be correct.