Where or how to recoat my mirror?

[12inchDoB]

Hi All, hoping this is the right place..

I need to get my 12" mirror recoated or ground? I just know it needs something lol

As you can see..

I live just north of London, and wondered if anyone could recommend a way of doing it or know of where i could get this sorted plz..

I can't remember much but is it coated in silver or something?

What options do i have..

Thanks

Stu

[GazOC]

Try Galvanopics Stu.

telescope kits, build your own. newtonian , dobsonian

(Welcome to SGL BTW!!)

[beamish]

Try Vacuum Coatings or Orion Optics as a starting point

[Moonshane]

hi Stu

I know of three that can sort this out :

Orion Optics UK Orion Optics UK

Galvoptics Galvoptics Ltd. Scientific and industrial optical components. lenses, mirrors, filters, prisms etc

Oldham Optical Oldham Optical Web Site

there may well be others.

[nightfisher]

you could try an email to orion optics in cheshire they do a recoat service and have a great reputation for mirrors

[beamish]

[Moonshane]

ps I agree your coatings need doing but I bet you'll be surprised at how good the view is even in this condition

[GazOC]

Like Shane says, you be surprised how bad a mirror can get without affecting the views too much. I'd try cleaning it first before you decide if recoating is needed.

[Moonshane]

here's a good method - important to do it the right way to avoid damage.

[12inchDoB]

Yea i was very surprised to see anything out of it,, i need to line it all up properly but not sure how to best do that either lol..

I cleaned it quite a bit but im kind of hoping a recoat will improve it dramatically!

Ill try them links..

thanks a lot!

Stu

[12inchDoB]

here's a good method - important to do it the right way to avoid damage.

OMG, wish i watched this first..

There was me with my brillo yesterday!

and no i aint joking!

[John]

OMG, wish i watched this first..

There was me with my brillo yesterday!

and no i aint joking!

If you really did do that the you may have to get the mirror re-polished as well as re-coated. Depends whether you have left any scratches on it.

Imagine a mirror 1 mile across. To be good for astronomy the variance in surface accuracy needs to be around the same as the thickness of a playing card on that scale. Thats why a brillo pad is not a good idea !.

[umadog]

If you used a Brillo on it then you ought to tell the coater what you did: get them to test the mirror before recoating.

[G4YVM]

I can vouch for Galvoptics. They did a cracking job on my 16" and for a very reasonable sum (two years ago).

David

[haitch]

OMG, wish i watched this first..

There was me with my brillo yesterday!

and no i aint joking!

Not wanting to be the bearer of bad news but on the other hand it's probably best not to skirt around it and just let you know (and also to warn others!)...

If you have used anything abrasive on the surface the cost to repair the damage will probably be expensive.

[ronin]

As you are in Cuffley then Galvoptics have to be the best option for a first contact.

You could drop the mirror off at their place, even take it there for them to assess and give some feedback or information before deciding.

Have to say it looks like it needs a recoat.

[swamp thing]

I can vouch for Galvoptics. They did a cracking job on my 16" and for a very reasonable sum (two years ago).

David

I'll second that, they've done my 10" cracking job.

Regards Steve

[12inchDoB]

Just been on the phone to Galvoptics..

Sound like nice people..

£112 + vat for a recoat of both mirrors..

takes 2-4 weeks to do and then apparently i shouldn't use it for a further 4-6 weeks to make sure it's hardened off..

Ill be pulling my hair out knowing thats sitting there all new n shiny!..

Ill have to borrow Davids 16" for a couple months lol

thanks guys

[Moonshane]

result!

you'll see a big difference.

[12inchDoB]

result!

you'll see a big difference.

Really? im getting all excited lol

as a %, how much better will it be after this mirror is redone compared to now? like

10%

15%

25%

30+%

:icon_scratch:

[Moonshane]

it's very difficult to estimate an exact figure to be honest but there's a lot of areas with no (or little) reflectivity and some scratches etc so I would expect it to be noticeable.

[GazOC]

Have you thought about hanging back until the summer and recoating it then when the nights are too light to get much use out of the scope any way?

[haitch]

It's not just the lack of reflectivity but the edge of patches where the coatings have gone (outside the secondary shadow) will be causing diffraction that will be degrading the contrast. I would guess it'll be in the 30% + range (going on my own experiences with a 14" mirror with coatings in similar condition apart from the scratches).

I am assuming for that the scratches are only in the coating and not through to the glass otherwise the recoat may not completely resolve things.

PS is the secondary held on by insulation tape? I wouldn't want to risk it falling on the primary!

[todd8137]

I'll second that, they've done my 10" cracking job.

Regards Steve

hi Steve what sort of price did they charge you i downloaded there file but could not open it