How do you take care of you scop after a viewing session?

[Chillie (Henry)]

Hi,

I had my collapsible Dobsonian telescope out tonight to have a look at Jupiter (more in another thread).

The conditions were still and a bit dewy. Dew started to form on the scope and covers. When I brought the scope back into a warm room the front lens on the finder scope fogged up.

At the moment, I have the OTA sitting on it's end, fully extended, pointing up with all covers off. This is to try to get rid of the condensation.

Did I do the right thing? It's probably too late now if I did. But if I did do the wrong thing, what is the best way to care for a telescope when bringing it in from the cold into a warm room?

[citivolus (Ric)]

Personally I stick my gear uncovered in a room with the ceiling fan on low until it is dry. However, nothing of mine has exposed mirrors.

OTAs get a quick once over with a hair dryer on low.

Nothing gets capped up until is is fully dry. If any optical surface accumulates a bit of dust during this time, it can be easily blown or rinsed off once there is enough to worry about.

No fungus or rust yet, and I've lived in marine climates since 2000.

You probably have less dust floating through the air in your house than you expose it to outside, unless you are a smoker or have the scope in the kitchen.

Regards,
Eric

[Chillie (Henry)]

Thank you for that Eric. All the condensation is gone and was capping everything up when you replied to my post in another thread.

Normally IIS is the third (but only astronomy) forum I visit outof five forums in total. But I was a bit worried about the condensation, so IIS is first on the list tonight.

I don't smoke and I keep the bass and OTA in the lounge room.

[Jules76 (Julian)]

Your post just gave me an idea. I work with Computers, so I can get hold of moisture absorbing Silicia Gel Bag's quite easily. And not those small ones you might get in multivitamin packets, but good size roughly 7x5cm bags which you'd need for such a large area inside a scope.

I'm wondering, if I attached one of these to the inside of the scope cover (on my reflector), and with something strong enough that it won't fall down to the mirror during transport, would this be a good idea? I was thinking of perhaps using an invoice plastic sleeve (you know the plastic sleeve you often find stuck to boxes with your shipping invoice inside) as it would be a perfect size for the Silicia bag and they stick very well. To help the bag "breathe" I could always punchure the sleeve with holes to allow moisture to get to the bag.

How does that sound? As much as you can take great care to remove all the moisture that may be inside your scope, at least with a Silicia Bag, you have something in all the time to remove any residual moisture that may have escaped your attention.

I'll have to give this a try when I return to work next week.

[astro_nutt]

I place my 10" dob in a warm room with the Moon filter removed from the dustcover and place a cloth over that so it will dry and prevent any extra dust sticking to the mirrors surface.

[rmcpb (Rob)]

If you have dew leave the scope open till its dry but tilt it over so the mirror is on its side. This will allow any real excess dew to run off and not pool in the bottom of the mirror curvature. In all honesty though, I have never had it run off as that would be a LOT of water.

To stop dust when the scope is open I use a bit of thin curtain cloth that is well washed. Just drape this over the openings and it allows the water out but not the dust in. No problems so far.

[CoombellKid]

I just cover mine where I was observing from and pack it up the next
day or afternoon. The morning sun dries it out in no time if Dew has
settled.

Cheers,CS

[dannat (Daniel)]

I would suggest pointing it down - or turn the scope over so the secondary if dewed can run off & it also runs off the mirror

[Chillie (Henry)]

Thanks for all of your tips.

There wasn't a lot of dew. It just felt slightly damp and the front lens on the finder scope fogged up when I brought the scope back into a warm room.

[hulloleeds]

Originally Posted by Jules76

Your post just gave me an idea. I work with Computers, so I can get hold of moisture absorbing Silicia Gel Bag's quite easily. And not those small ones you might get in multivitamin packets, but good size roughly 7x5cm bags which you'd need for such a large area inside a scope.

I'm wondering, if I attached one of these to the inside of the scope cover (on my reflector), and with something strong enough that it won't fall down to the mirror during transport, would this be a good idea? I was thinking of perhaps using an invoice plastic sleeve (you know the plastic sleeve you often find stuck to boxes with your shipping invoice inside) as it would be a perfect size for the Silicia bag and they stick very well. To help the bag "breathe" I could always punchure the sleeve with holes to allow moisture to get to the bag.

How does that sound? As much as you can take great care to remove all the moisture that may be inside your scope, at least with a Silicia Bag, you have something in all the time to remove any residual moisture that may have escaped your attention.

I'll have to give this a try when I return to work next week.

Unless the scope is really, really dry you will find that the silica will quickly be used up. It will work better in a sealed environment, too.