Dobsonian dust cover - ideas?

[stevejack]

Hi guys, I have a 14" Skywatcher GOTO scope (the collapsible type). It has a hard cover for the top of the base tube which is supposed to protect the Primary but it doesn't do a lot. The mirror is filthy at the moment, after only about 5 months.

The base is open at the bottom and I can imagine that dust gets blown onto the mirror from there as the floor is swept and so on.

Has anyone made a cover just to cover the mirror itself? Is there a particular material to avoid/use to prevent damage to the mirror surface?

If that's a bad idea, I guess a cover to go over the whole scope would be an option.. as long as it tucks in and covers up that gap at the bottom. Again, is there a preferred material to use to avoid problems like moisture retention etc?
Any ideas would be appreciated.

Cheers

[Satchmo]

http://www.telegizmos.com/Tube%20Dob%20Covers.htm

[erick]

Solid tube dobs are nice in this respect since you can normally seal them by putting the endcap on, fitting a plug to the focusser and putting a "shower cap" or similar over the mirror end. I've heard of too many scope with spider webs, insect eggs, cat on the mirror etc!

But truss dobs and those with lots of open areas around the rear of the mirror are a problem to seal. Even the wonderful telegizmos covers won't seal that gap at ground level. In my experience, the draw string is useful, but not perfect.

I was out at a bush site for many days and every time I removed the telegizmos and other covers off the the scope, I checked carefully, expecting to find a snake sleeping peacefully on my mirror. Thank goodness, none found!

Storing at home, I:-

1) place it up on a low table to get it of the ground.
2) place the scope on a sheet, the edges of which I then lift and cover the scope (rocker/mirror box), or at least tuck in somewhere a bit higher on the scope. Then another cover could be thrown over top and a draw string pulled, or elastic rope wound around the scope to seal it inside the covers.

Neither of these steps are conveniently done in the field, unfortunately.

I'll love to see a designed solution that would allow the entire scope to be wrapped in a breathable cocoon after use each night.

[dalemadison]

I went to BBQ Galore and bought a cover for a weber kettle. I covers the scope well when it is collapsed. use a elastic cord to keep it tight.

[Sarge]

Steve,
For my 12" SW, my wife made a calico loose fitting cover, that goes right to the floor. Keeps out dust but does not sweat. :thumbsup:
Also purchased a vynal cover for a upright gas heater cover from K-mart ($8), the patio type. Does not quite fit to base, but fits comfortably over the OTA and does keep moisture and dust out when not in use for long periods.
All in all 2 covers for less that $20.

Rod
:D:D