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I'm in the Wrong Business...


niallk

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Just now, Steve Ward said:

Rather dry powder than foam ... :icon_biggrin:

I would have thought at the speed the dry powder travels at from a discharged extinguisher that it would scratch up the ultra thin mirror coating therefore foam is probably safer although messier! Plus I was under the impression that foaming cleaners lifted debris away from the surface?

 

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On 03/10/2016 at 19:25, niallk said:

I'm looking to clean my mirrors, and trying to source distilled water.  Boots chemists will sell me 2litres for €17 :eek:

Please tell me this price is ridiculous and that I should be able get it somewhere much cheaper...

The price is not ridiculous ! What is ridiculous is going to Boots for mirror cleaning water !!

In respect of front-surface aluminised mirrors the terms "distilled" and "de-ionised" are legacy descriptions, from when that was all that was available and from when distilled clean water was common practice and thus cheap.

Since then distilled water for common practice has become a lost art and only used for exotic laboratory requirements. Similarly de-ionised water was often used for replacement activities such as steam irons and battery top-ups in places where motor mechanics lurked ( would you?) and where posh householders wanted to have soft water on tap. The latter used salt ion exchange and the former (&more discerning chemists) used strong cation and anion exchange (hydrochloric acid and caustic agents etc some of which can/may persist in the product if rigorous lab practice is not maintained) resins ( I still have some !)

The upshot is (as previously said) Reverse Osmosis (RO) water commonly available, not least in your local tropical fish emporium, is more than adequate.   It is all down to common usage, time was when RO was exotic and expensive, if yer marine trops can live in it your average speculum can :)

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2 hours ago, SilverAstro said:

The price is not ridiculous ! What is ridiculous is going to Boots for mirror cleaning water !!

Ha ha!

Thanks for the comments & explanations - doesn't seem as straight forward to source distilled here in Cork, so I tried the often suggested route of pharmacies.

I'll see how thing go on my 10".  Given that it must be ~7yrs without cleaning, residues from RO water would have to be pretty significant to be worth talking about when it comes to the before and after comparison :)

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5 hours ago, Paul73 said:

Just checking that we are talking about the final rinse so that the mirror is free of deposits and streaks?? I use warm tap water and washing up liquid for the main wash which is as close to zero contact as possible. Then rinse.

Paul

Hi Paul - yes the final rinse :)

So looking at the surface of my 15", I think it needs to soak, and I want to get a clean container and will do like you say - after an initial rinse off of any 'loose' particles.

Ideally I'd avoid touching the front surface all together, and just swish water around. Looking at my mirror, I'm apprehensive that it will take some 'rubbing'. How do you do it? Eg lightest rub with fingers, or cotton wool under just its own wet weight?

I'm thinking of fully submerging the mirror - anyone with concerns about doing this?  While I could wash in situ in its cell, I will be removing it to re-spot.

 

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Just use 100% natural cotton wool and drag it lightly across the surface whilst under water - zero pressure. This is the gentlest way that I have found. A mirror has got to be pretty dirty before it is worth washing.

Paul

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12 hours ago, Steve Ward said:

Hardly pure , likely to be contaminated from the metal condensing plates and other internal surfaces , not to mention the mould and bacteria that lurk in such appliances .

Not safe to drink so certainly wouldn't use it myself , classed as 'grey water'.

Could well be ideal conditions for legionella as well.

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6 hours ago, niallk said:

Ha ha!

Thanks for the comments & explanations - doesn't seem as straight forward to source distilled here in Cork, so I tried the often suggested route of pharmacies.

All understood. Yes, in the cold light of day re-reading my comment it may not have come over as the chuckle I intended at the lengths we go to to take care of our nearest and dearest :)

Also, I dunno about in Cork, but tropical fishkeeping is not as common as it once used to be either :( , but a fishkeeper would be able to give you gallons of the RO.

Aluminium, with its coating of oxide, is remarkably durable so the main worry is abrasion from particles and streaks from evaporation deposits ( of calcium/magnesium - 'hardness' components) and non of those will be in RO water (nothing much gets through the osmotic membrane, even bacteria are too big to get through some of them)

As for distilling, it is technically illegal to possess a still still ! over here, but never prosecuted unless engaged in "other" activities, so you could go that route for the rinse water, maybe  ?!

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On 03/10/2016 at 19:25, niallk said:

I'm looking to clean my mirrors, and trying to source distilled water.  Boots chemists will sell me 2litres for €17 :eek:

Please tell me this price is ridiculous and that I should be able get it somewhere much cheaper...

The price is ridiculous naillk, and you can get it much much cheaper elsewhere.

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I did a quick calculation and  it would cost about £1 a pint if you distilled your own (triple pass) but as with most things in the UK certain chemicals that have other uses like Distilled water and IPA are hard to get.

Alan

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Surely one pass would be sufficient ?

The sun is free ( and appropriate dont you think :)  ) Solar Still https://en.wikipedia.org/wiki/Solar_still  For those of a nervous disposition they can be made out of glass, but the plastic versions are quick and easy, though quick may not be the right word and frequent is not needed lol!

Oh! I know a dew collector ! Put it to a good use for a change :D

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On 10/4/2016 at 12:27, scarp15 said:

I get my RO distilled marine water for free from an aquarium retailer in a local Garden Centre. I just made an initial purchase for a 5lt container and take that with me each time. 

Ditto

 

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3 hours ago, Stub Mandrel said:

LOL!

Just put a bowl under your telescope...

 

3 hours ago, SilverAstro said:

Would you believe, the very next topic I went to read after posting my "Dew" bit was the Telrad one https://stargazerslounge.com/topic/278927-is-wiping-the-dew-from-your-telrad-the-done-thing/ so I was on my way back here to suggest small gutter ( dolls house?) a pipe and a bucket.

You beat me to it :)

Ha ha ha!

I've even got two Telrads, so I could go into mass production :grin:

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8 hours ago, Pippy said:

But dew would contain the very bits and pieces and lumps from the atmosphere that you do not want in your cleaning water ?

I dont think we were being entirely serious about dew :)

But since you ask - no, it doesnt drip out of the sky like rain, it condenses directly from the vapour in contact with the cold surface, so provided you keep your telrad glass clean (and dont do it next to a bonfire or similar) you would be ok ! I think !!

Rain water would be ok if filtered. But I dont think anyone is going to do that, so best not start one of those here :angel4:

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