Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_lunar_landings.thumb.jpg.b50378d0845690d8a03305a49923eb40.jpg

Norfolk star gazer

Moisture On Primary Mirror

Recommended Posts

I had an early morning session with the scope today (very cold) and got in at about 7.30.

I left the dust cap off the 10" dob so that the moisture could evaporate, but 5 hours later it is still there.

Should I just leave it alone in the cold garage and see what happens (probably will want to use it tonight) or bring it in the house to warm up or take a hair dryer to it?

If the hair dryer is the best option, should I lay the scope flat on the dob mount and blow down the tube or blow the hot hair at the mirror end?

Share this post


Link to post
Share on other sites

If you want to use it tonight, perhaps put the tube level and blow the hairdryer down towards the mirror, just on a cool or warm setting, not hot. The air circulation should help clear the dew.

  • Like 1

Share this post


Link to post
Share on other sites

If you want to use it tonight, perhaps put the tube level and blow the hairdryer down towards the mirror, just on a cool or warm setting, not hot. The air circulation should help clear the dew.

I assume just leaving it alone (if I don't use it tonight and give it a chance to thaw out - so to speak) won't harm the mirror if the moisture doesn't go? It's quite a cold garage today.

Share this post


Link to post
Share on other sites

I assume just leaving it alone (if I don't use it tonight and give it a chance to thaw out - so to speak) won't harm the mirror if the moisture doesn't go? It's quite a cold garage today.

My preference would always be to clear the moisture relatively quickly to prevent it accelerating any deterioration in coatings. A few nights won't hurt but over a prolonged period it is less good. If not using tonight I'd be tempted to bring it into the house to clear it

Share this post


Link to post
Share on other sites

Thanks. I gave it a quick blow dry on a low setting as suggested and it cleared in minutes. Just left with a slightly dirty mirror that has accumulated some dust. Nothing major like a dead fly, so nothing to affect the view too much.

When I'm feeling brave, I might give it a clean, but know that isn't easy!

Share this post


Link to post
Share on other sites

Good stuff. Don't worry about a bit of dust, no need to clean it for a good while yet

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.