New 10" Dob - Cold and Dew conditions

[209herschel (Herschel)]

Hi all, I've spent a few hours this past week learning about my new 10" dob and I love it. Now that it's the weekend, I worried about leaving it outside too long as it gets pretty dewy out there. I took my scope into the yard, gave it 30min to reach outside temp, and watched the moon rise. Incredible fun. That was two hours ago and I'd like to go out again at around 11pm when the neighbour's lights are off, etc. Is it okay to leave the scope outside with the cover on for a few hours in this cold, moist environment? I know people spend all night out at star parties so I thought it should be fine. I just thought I'd ask as I already noticed a couple of spots on the primary. Thanks in advance.

[N1 (Mirko)]

Good to see you are enjoying your dob. The OTA can handle a bit of moisture. I just keep it horizontal when not in use and left out for a while. The mount is another story. Apparently the finish is one of the areas where GSO had to cut some corners to achieve the competitive price. The MDF of the mount will not respond well once water does get to it. I haven't sealed mine yet, but it's on my to-do list. I'm thinking something silicone based.

[209herschel (Herschel)]

Originally Posted by N1

Good to see you are enjoying your dob. The OTA can handle a bit of moisture. I just keep it horizontal when not in use and left out for a while. The mount is another story. Apparently the finish is one of the areas where GSO had to cut some corners to achieve the competitive price. The MDF of the mount will not respond well once water does get to it. I haven't sealed mine yet, but it's on my to-do list. I'm thinking something silicone based.

Thanks very much for the reply. Actually, it reminds me of a few posts I came across about sealing the base. I'll look into that now. Cheers.

[glend (Glen)]

Hmm, where did he say it was a GSO? The assumption regarding the base applies to all of the production dobs that use a pressed chipwood panel covered in laminate. Your dob should have a cap to close off the tube end and it will actually gather less dew on the tube if left parked in an upright position. External dew can always be wiped off. If you are storing it inside it will fog up substantially when you bring it in. Just wipe off the external moisture when you bring it in and leave the cap off so that any internal moisture can evaporate as it equalises. I have left my dobs outside all night at star parties and dew has never been a serious issue. One thing you might look into is getting a camping popup toilet cubicle to put over the dob if you want to leave it out unattended for long periods. These cubicles are always vented and when closed will keep dew from settling on the scope. Good luck with the new scope.

[209herschel (Herschel)]

Originally Posted by glend

Hmm, where did he say it was a GSO? The assumption regarding the base applies to all of the production dobs that use a pressed chipwood panel covered in laminate. Your dob should have a cap to close off the tube end and it will actually gather less dew on the tube if left parked in an upright position. External dew can always be wiped off. If you are storing it inside it will fog up substantially when you bring it in. Just wipe off the external moisture when you bring it in and leave the cap off so that any internal moisture can evaporate as it equalises. I have left my dobs outside all night at star parties and dew has never been a serious issue. One thing you might look into is getting a camping popup toilet cubicle to put over the dob if you want to leave it out unattended for long periods. These cubicles are always vented and when closed will keep dew from settling on the scope. Good luck with the new scope.

Thanks very much the information. I've just taken the cap off and I'll leave it off for an hour or so to help any moisture evaporate. Cheers.

[N1 (Mirko)]

Glen, I see what you are saying. I'm just not sure what's better - more moisture on the tube when parked horizontally, or moisture travelling down the outside of the tube and accumulating along the edge of the mirror cell, where it joins the tube. I suppose the best solution is to just cover it when not in use.

Re mount, I recall the OP contemplating a GSO in another thread. The fact that other, more expensice dobs have the same problem only shows that GSO dobs are damn good value.

[Scott_VanColeco]

I have a 10" dob also and I leave it out all the time. My only advice would be to keep the base up and out of the wet grass if it's on your lawn. I keep my dob on a small garden cart.

[Skuppy (Chris)]

Hey Scott,

I am interested in what you have been seeing with your 10" dob.
And what sort of quality viewing
As I am shopping myself for one

cheers

[209herschel (Herschel)]

Originally Posted by Scott_VanColeco

I have a 10" dob also and I leave it out all the time. My only advice would be to keep the base up and out of the wet grass if it's on your lawn. I keep my dob on a small garden cart.

Thanks very much. I ended up buying one of those small dolly platforms from bunnings and I'm happy with the solution. I was wondering if it matters whether the scope is level? My yard has quite a slope. I've been out 3 times now in the yard. Yesterday I finally saw the rings of Saturn. But I was concerned I should have seen more detail. Even with the 9mm it was quite small and I don't think I could really make the Cassini division. Can you give me an idea of what Saturn looks like in yours? Thanks again?

[209herschel (Herschel)]

Originally Posted by Skuppy

Hey Scott,

I am interested in what you have been seeing with your 10" dob.
And what sort of quality viewing
As I am shopping myself for one

cheers

Hi Chris, I'm interested in this also. I was viewing Saturn last night and saw the band but I couldn't make out the Cassini division even with the 9mm. Can you give an idea of what Saturn looks like in yours? Cheers