Cleaning OTA

[PeeKayHaitch]

Hi all

I Have just purchased a secondhand Skywatcher 130 reflector and whilst having a good look around I have noticed that there are a number of very thin cobwebs down the length of the tube, obviously did not have end cap in place all the time. What is the best method to remove cobwebs and clean inside of the tube? Should I remove the primary mirror to clean the tube? What is best way to clean the mirrors as I guess if tube has cobwebs then there will be dust on the mirrors?
Many thanks

Paul

[ScottS]

I wouldn't clean the mirror if all you have is some fine cobwebs and a light coating of dust. You may be able to just gently brush/pull the webs from the tube as is. Just be very careful with any optical surfaces though.

[LouisJB]

hi, you could take the mirror cell out (carefully) and store away from the tube. Then you can give the tube a hoover out as required. The cell comes out really easily, just be super careful with it and put it in a safe place (on its back, where nothing can fall on it).

As for the primary mirror, leave it - unless it's really bad, then you can clean with soap and water but find an online guide first and read it. I think also you'd want to rinse with distilled water when clean so you'd need to have some to hand before starting. I think this sort of cleaning is only done when absolutely essential, so unless the mirror is looking so bad it can't be used it's best to leave it alone.

[NGC 1502]

Hi Paul, difficult to be certain without seeing it, but the cobwebs are unlikely to affect the view.  If the mirrors look clean, then they are as clean as they need to be, so I'd leave them alone.

You could, being very careful not to touch the primary or secondary mirrors, tie a small clean cloth on a long stick, then remove the cobwebs. Take your time, no rush, perfection not needed.

Keep a good grip on the stick.   The scope won't perform any better, but you will feel better 

I see you are in Essex. My club has public events you may wish to attend - http://www.cpac.org.uk/opennight.asp  - but please check the weather forecast to save a wasted journey.

Regards, Ed.

[ScottS]

Hi Paul, difficult to be certain without seeing it, but the cobwebs are unlikely to affect the view.  If the mirrors look clean, then they are as clean as they need to be, so I'd leave them alone.

You could, being very careful not to touch the primary or secondary mirrors, tie a small clean cloth on a long stick, then remove the cobwebs. Take your time, no rush, perfection not needed.

Keep a good grip on the stick.   The scope won't perform any better, but you will feel better 

Regards, Ed.

I would also, in addition, tilt the tube to the horizontal first to avoid any dropped articles onto the primary.

[NGC 1502]

I would also, in addition, tilt the tube to the horizontal first to avoid any dropped articles onto the primary.

Good point Scott, should have said that myself.

Cheers, Ed.

[Peter Drew]

How about a Ken Dodd type "tickling stick" 

[PeeKayHaitch]

Thans for the advice guys, will give it a go tomorow

Paul