Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

Anyone know where to get BPC cotton wool ?

perrin6

Recommended Posts

perrin6

perrin6

Posted
Posted

(Blimey - took about 15 mins to find out how to start a thread !)

I need 'BPC cotton wool' for cleaning mirrors ('BPC' is a standard that has no abrasive fibres in it). Cannot find it in any chemists even major chains (get blank looks). I ordered some on the net but the post office lost it so I just want to walk into a shop & buy some if poss.

Thanks,

Alan.

Link to comment
Share on other sites
Andrew*

Andrew*

Posted
Posted

I've never found BPC over the counter. Just try online again. Post office lose very few parcels, so second time lucky!

FWIW, I've used the dreaded infamous ordinary cotton wool on lenses without issues - never seen a scratch and always got pristine results. Mirrors is a different matter of course.

Andrew

Link to comment
Share on other sites
Moonshane

Moonshane

Posted
Posted

I always thought that it just mean 100% cotton wool? here's something off the net re BPC - I am not sure it really means anything?

Proper noun

British Pharmaceutical Codex

  1. the BPC - a book of reference, published by the Pharmaceutical Society of Great Britain, intended to aid those engaged in the prescribing and dispensing of medicines. It had a companion volume, the British Pharmacopoeia.
Link to comment
Share on other sites
Tantalus

Tantalus

Posted
Posted

I was looking for some last year. Tried nearly every chemist in town, until I eventually found one that sold me some over the counter. They didn't have it on the shelf, but a helpful member of staff did manage to find a pack in their stock room. I don't think they normally sell it to the general public because it wasn't priced up, and it took them some minutes to find an invoice. I think i paid around £2.38 for a 100g pack.

IIRC the difference between BP (same as BPC) cotton wool and the stuff you buy in the shops is the BP stuff is also sterilised and contains no oily residues. What surprised me is how few pharmacists seemed to have heard of BP. As someone who's been a First-Aider for some years, I come across the BP mark frequently.

Link to comment
Share on other sites
MG1

MG1

Posted
Posted

Try talking to the pharmacist....I managed to get it from our local pharmacy in Bristol....now IPA is another matter!

When I asked for that first I got the third degree...do I look like a druggy or terrorist? ....then was told it's not available for purchase.

They did sell me some distiller water though.

However regarding cotton wool. Just be careful not to get fibres caught around the lens cell edge. A real [removed word] to get out.

Someone recommended the paper wipes used for CCD cleaning, not tried it myself though.

Most importantly though....does it really need cleaning. It is possible to get a little obsessive over a little dust etc...and I consider every clean a risk. Therefore I don't do it very often, once or twice a year if needed.

Michael

Link to comment
Share on other sites
perrin6

perrin6

Posted
  • Author
Posted

Thanks Kev but not sure that lens tissue is suitable for cleaning astro mirrors, don't know why though exactly, perhaps cos it's too thin and contaminants seep through from fingers ?? (pec pads - sounds like something body builders clean their muscles with ! :))

Michael - blimey! IPA must be powerful stuff ! - I'll treat it with more respect next time I use it.:) I think I need to clean the mirrors more often as they get a lot of tiny spots on them which, if oily, must be a lot worse than dust as they prob. refract light rather than just block it like dust does. Not sure what they are, was wondering if they come off nearby trees or bushes. They're a devil to remove as washing-up liquid nor alcohol dissolves them alone, only with cotton wool or similar plus some considerable pressure.:p

Thanks Tantalus for info.

Alan

Link to comment
Share on other sites
Moonshane

Moonshane

Posted
Posted
Try talking to the pharmacist....I managed to get it from our local pharmacy in Bristol....now IPA is another matter!

When I asked for that first I got the third degree...do I look like a druggy or terrorist? ....then was told it's not available for purchase.

They did sell me some distiller water though.

However regarding cotton wool. Just be careful not to get fibres caught around the lens cell edge. A real [removed word] to get out.

Someone recommended the paper wipes used for CCD cleaning, not tried it myself though.

Most importantly though....does it really need cleaning. It is possible to get a little obsessive over a little dust etc...and I consider every clean a risk. Therefore I don't do it very often, once or twice a year if needed.

Michael

Shiny Hardware Limited were very good when I bought some Acetone recently.

they stock IPA which is 99.9% pure, I presume the 0.01% is water?

Link to comment
Share on other sites
MG1

MG1

Posted
Posted
Maplin Sell IPA either as an Aerosol or in 500ml tins without giving you the third degree...

Peter...

Cheers Peter

That's where I went in the end....I've been told to avoid the aerosols though as the propellant might damage coatings, but don't know if this is true?

There's no indication of the purity of the tin though, but since I'm diluting it with distilled water I'm not sure it matters that much. Unless the non IPA is something nasty.

Link to comment
Share on other sites
Carbon Brush

Carbon Brush

Posted
Posted

Beware IPA!

If it is pure (isopropanol) there are few issues. But if you buy from a dubious source, it may contain other things. In good quality form it is used as a cleaner/solvent in electronics work. But for lens coatings. Not so sure about problems.

Two of us at work used it for cleaning our spectacle lenses. Over a period of time the anti reflective/hard/whatever coatings started to come off. A few cleans were no problem. But after a lot of use, it was new lens time. These were lenses of diffferent ages from different manufacturers, so it was not a batch problem.

For astronomy & camera) optics I would suggest minmial use of IPA. Mixed with distilled water if possible.

Next problem. Buying distilled (rather than de-ionised) water.

Link to comment
Share on other sites
MG1

MG1

Posted
Posted

Distilled water definitely available from chemists...you have to ask though.

This time when they queried my usage I just told them I was fussy about my tea!

Got a raised eyebrow which is as far as our droll pharmacist gets towards an outward display of emotion!

Was planning to mix IPA 50/50 with distilled water, does that sound okay?

But might wait until I can find some purer stock.

Michael

Link to comment
Share on other sites
perrin6

perrin6

Posted
  • Author
Posted
I suspect this is tree sap?

I mentioned this prob before on here and a kind & bright soul suggested experimenting by placing an ordinary mirror outside overnight so that I could use it to try different techniques/chemicals on the spots so I have put an old 8 - inch mirror in the garden for a couple of days. (Please be calm all you optic-sensitive astronomers out there - I ruined the figure when experimenting with various ways to remove the coating while planning to refigure my 350mm !:)).

Alan

Link to comment
Share on other sites
perrin6

perrin6

Posted
  • Author
Posted
Distilled water definitely available from chemists...you have to ask though. Michael

Michael,

I am using ionized water obtained from an aquarist as it is much cheaper than from other sources. I forget the exact cost now though.

Alan

Link to comment
Share on other sites
dph1nm

dph1nm

Posted
Posted
Two of us at work used it for cleaning our spectacle lenses. Over a period of time the anti reflective/hard/whatever coatings started to come off.

Indeed - I mentioned to my optician that I use those alcohol soaked wipes to clean my glasses. He said don't - modern lens coatings are soluble in alcohol!

NigelM

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.