Getting muck off filters

[Carole]

I have an IR filter which seems to have a couple of larger bits of dust stuck to it. 

I have some lens cleaner and some cotton buds, is it safe to do this, or is it better to live with the dust?

Carole

[Mike]

Clean the filter gently under warm (not hot) running water and a tiny bit of washing up liquid, use your fungers, be gentle.

Rinse off the filter, rinse it off again but this time with distilled water (you can buy it in Halfords), now dry it with a hairdryer on the cold settings.

I've washed both filters and scope mirrors using the above and it works a treat.

[Carole]

Thanks Mike.
I did clean one of my objective lenses using my suggested method recently and that worked a treat too, but wasn't sure about filters.

Carole

[Carole]

I have distilled water in the house, so have done it and it worked fine.

Thanks Mike

Carole

[The Thing]

For the greasy bits, acetone works very well. Do not use it on anything with paint though!

Be aware washing up liquid contains salt which can damage coatings and corrode fittings. If you can get it, photographic wetting solution is best (a sort of detergent used in the days of film and wet paper processing). Trouble is it's almost impossible to find these days.

[mickw]

Just a thought - I think salt is used as a water softener (no idea how), what are the contents of the "eco" cleaners ?

[JonH]

Pretty much all chemicals and solvents carry a risk of some sort, i personally would stay WELL clear of acetone though as that is nasty stuff!
From what i was told at work decent quality optical wipes which are dust and fibre free (i have loads if anyone wants one or two) and your breath will always give excellent and safe results!

[MarkS]

Just a thought - I think salt is used as a water softener (no idea how)

The water in our house is softened - the salt replaces the calcium and magnesium ions with sodium ions - so you don't get limescale.

Our kettle, our kitchen and bathrooms all look as good as new ...

We have a tap with unsoftened water for drinking.

Are we sure Halfords sell distilled water - I've only ever managed to get de-ionised water - which still has salts in it which can leave deposits on your mirror/lens.  But much better than tap water.

Mark

[Ian]

hehe, there's a topic in itself.

What's the difference between deionised water and distilled water?

I understood that it's merely the process used to purify the water. The end result is the same stuff.

Discuss.

(hate it when someone ends a comment with "discuss", don't you?)

[JonH]

Well I don't know about how deionised water is 'deionised' but I thought distilled water was 'made' by boiling it and condensing the steam thus leaving all the crud behind.

[RobertM]

Are we sure Halfords sell distilled water - I've only ever managed to get de-ionised water - which still has salts in it which can leave deposits on your mirror/lens.  But much better than tap water.

Mark

De-ionised water will only have (dissolved) salts in if it isn't de-ionised any more.  On the other hand if there are undisolved particles in it then the residue isn't great for optics.

Personally I use Baader wonder fluid for cleaning optics.  It's easy to apply via the spray and easy to wipe off and dries without leaving a film.

Robert