Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_dslr_mirrorlesss_winners.thumb.jpg.9deb4a8db27e7485a7bb99d98667c94e.jpg

perrin6

Anyone know where to get BPC cotton wool ?

Recommended Posts

(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.

Share this post


Link to post
Share on other sites

Looks like a lot of 'blank looks' on this site :p

Dont know how to clean it without BPC c. wool.:D Am scared to use the ordinary',:)

Alan

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

Thank you Andrew and Shane. Will maybe perhaps chance it online again possibly......or not.

Alan

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

For cleaning lens and ccd sensors I use a product called Pec pads which are lint free tissues and Eclipse fluid which is 100% pure methanol. Both are readily available from photographic centres like warehouseexpress

Edited by Photosbykev

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites
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?

Share this post


Link to post
Share on other sites
...... (pec pads - sounds like something body builders clean their muscles with ! :)).....

Alan

You've put me right off them now :)

Share this post


Link to post
Share on other sites
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.

Share this post


Link to post
Share on other sites

Its a litre tin not 500ml and it lists lens cleaning as one of its uses...

I used to spray the aerosol one into a container and let it vent off before using it for lens cleaning...

MSDS info here...

http://www.semenedis.com/include/hs/AID3034.php

Methanol is much nastier stuff...

Peter...

Edited by Psychobilly

Share this post


Link to post
Share on other sites

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.

Edited by DavidValentine

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites
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

Share this post


Link to post
Share on other sites
Maplin Sell IPA either as an Aerosol or in 500ml tins without giving you the third degree...

Peter...

I hope no one tries to clean their delicate optical surfaces with Indian Pale Ale !:)

Alan

Share this post


Link to post
Share on other sites
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

Share this post


Link to post
Share on other sites
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

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.