recoat or new scope?

[Jedite83]

I was given a telescope by my FIL a few years back that he had been storing in a back room in his  house. I cleaned it up and it worked great. However I ended up having to store in in a storage unit for a couple of years, taking it out from time to time to use it. I have been able to take it out and am planning on using it regularly but I noticed that the secondary (and to a lesser extent the primary) mirrors look like they are oxidized or somthing. I tryed to clean them, but it made zero difference. I am thinking that I should have the mirrors recoated and I can afford it. However I was wondering should I recoat or just buy a new telescope. The scope I currently have is a Telestar 114AZ (114mm diameter). Looking at amazon I could pick up a new scope for to to much more the the recoat would cost.

Is it worth it to recoat or replace?

[RT65CB-SWL]

First off @Jedite83 welcome to SGL.   If you can add some photo's than we can advise better.

• Second: if it is sentimental value; then maybe keep it... I will leave that decision for you to decide.
• Third: what did you use to clean it? - there are plenty of sites, including here, on how to clean mirrors.
• Fourth: what do want to view. 114mm will show the Moon in greater detail; the phases of Venus, Jupiter and its Galilean Moon's; i.e. Io, Europa, Ganymede & Callisto; Saturn and it rings... and maybe its largest moon Titan, some DSO's. 
• Fifth: any 'scope is better than none.

Other SGL'ers will hopefully suggest what is best for you and what else you can view with it.  

Wishing you and your family clear skies.

Edited April 18, 2020 by Philip R

[NGC 1502]

Firstly perhaps you could post some pics on here of the mirrors.  Mirrors that appear not so good can still work surprisingly well.   Most optical surfaces look less than pristine especially when viewed with a bright light.

However, if the coatings have deteriorated too far -

If you can replace for similar cost to recoat, I’d definitely replace.   Much simpler too, saves you dismantling, packing the mirrors securely for posting, reassembly later.   You could keep the old scope as a memento of your relative.

All the best with your decision, Ed.

[Carbon Brush]

As NGC1502 said, degraded and mucky mirrors often still work remarkably well.

Dismantling, cleaning and re-assembly on a simple newtonian scope is an excellent learning experience.
Then one day when you dismantle a big expensive scope, you have an idea of what you are getting into.

My last mirror clean was on a very neglected (not by me) 10" reflector. I wondered if the mirror was damaged beyond hope.
It took a long time to soak off the bugs, dust and everything else. But at the end it is still a really good mirror.

HTH, David.

 

[Jedite83]

i'll take some photos and post them in a bit. (have to wait for my camera to charge). I know that even dirty mirrorsw still can work, but the secondary is not reflective, but has a frosted look to it.

My wife had asked if just replacing ht mirrors was an option and looking online it does look like it could be more affordable of an option, but all th emirros I am finding have a different focal lenght (they are 900mm and my scope is 910mm).

Edited April 18, 2020 by Jedite83

[Jedite83]

Here are some shots of the primary

[hawksquawks]

If the recoat is cheaper than buying a new scope of the same size then I would go for a recoat, the benefit of doing so will save another scope from the land fill. That said you may be able to find a second hand telescope that's cheaper than a recoat id consider that option also.  I managed to pick up a 120mm refractor with an EQ3-2 mount for £125, and in the past a 130mm reflector for just £60     

[Jedite83]

I ended up ordering a replacement secondary mirror and spending more time re-cleaning the primary.
Got the replacement mirror yesterday, installed it and culminated it. Took it out last night and was able to view the moon, Venus, Jupiter and Saturn. 

[RT65CB-SWL]

William Parsons, £rd Earl/Lord Rosse, 'Leviathan of Parsontown' telescope at Birr Castle, Offlay Eire 🇮🇪 ; had two primary mirrors made for it, and the coatings were made from speculum* and because it degrades rather quickly and is extremely fragile. I assume the secondary was also speculum* too. (I need to research this). I can imagine you and him comparing notes and exchanging ideas. 

 

* the ingredients for speculum are: 2/3 copper - 1/3 tin