Reflector refurb

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Joined: 28 Jan 2015, 00:57

Reflector refurb

Postby curlysue » 12 Jan 2017, 14:04

Hi... can anyone recommend somewhere (preferrably in or close to Fife) that can refurbish and realign reflector mirrors? Many thanks, Suzanne :D

Posts: 171
Joined: 07 Sep 2007, 20:24
Location: Rosyth

Re: Reflector refurb

Postby justanotherpete » 16 Jan 2017, 14:14

When you say refurbish are we talking cleaning (washing) which can be done at home once the mirror has been removed from the telescope tube using a process like this one...

Clean the sink out.
Have some dry clean towels handy, thin ones are best.
Cotton wool (surgical grade is best if you can get it).
Dish soap.
A 5 Litre canister of distilled water.
Fill the sink up with luke-warm water (you don't want to add any thermal shocks to the mirror) enough so that it will cover the mirror plus an inch or so.
Add a small squirt of dish soap to the water and swish it around a bit.
Lower the mirror into the water, hold it by the edges, do not touch the mirrored surface.
Let the mirror soak for a few min, then holding it by the edges swirl it around a bit in the water.
Take a some cotton wool and gently, with no pressure on the mirror surface, just move the cotton wool over the mirror surface.
Lift the mirror out of the sink, again holding by the edges, and place it, face up, on one of the towels.
Empty the sink and rinse it, then refill with lukewarm water to the same depth, no dish soap this time.
Lower the mirror in, again holding by the edges, and swirl it around to rinse the previous soapy water off.
Lift the mirror out of the sink, again holding by the edges, and place it, face up, on one of the towels.
Empty the sink and rinse it.
Lower the mirror into the empty sink, again holding by the edges, and rinse again, this time by pouring distilled water directly from the container over the mirror surface.
Once it's rinsed off, lift the mirror out onto another towel and then stand it on it's edge, let the mirror dry off in the air, do not wipe it or use a hair dryer on it. Make sure it's supported and chocked so it won't roll. This will avoid shattering experiences :)
Once it's dry you can re-assemble it into your mirror cell and replace it on the telescope tube.

If the mirror actually needs recoating then that has to be done by specialists and you'll need to send it away for that. Usually this only needs doing every 3-5 years depending on storage conditions.

For re-alignment Paul Holmes is probably your best bet, I know the theory but being a refractor man, have little actual practice.
Hope that helps.

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Joined: 15 Nov 2006, 22:03

Re: Reflector refurb

Postby admin » 18 Jan 2017, 00:10

As Pete says, yes I can do Newtonian alignment - just bring your scope along and leave it with me for a day or two.

Cleaning can be done in the kitchen sink (see above, or this video), and Orion Optics in Newcastle-under-Lyme do re-coating.

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