[Shiraz (Ray)]

I normally stagger out to cover the scope (Newtonian) at around dawn, turn everything off, roll over the roof and go back inside for a cup of coffee. Today I did the normal procedure, but went out again at about 10am to check on a slight collimation issue - and found the mount to be dripping wet and the mirror with rivulets of water on it!!!! How come, since I don't have dew trouble when imaging and it was dry 3 hours ago.

What seems to have happened - and possibly has been happening for months without me being aware - is that dew from the previous night had settled all over the interior and floor of the obs and then evaporated as the sun warmed the walls and roof. This airborne water then condensed on the nearest cold things - the mount and the mirror, both of which were still at night temperatures.

I think that I will have to install fans to blow ambient air across the mount and scope to warm it up more quickly as the air in the obs warms - and to exhaust the humid air as well. I already have chloride absorbers (laundry style) in the obs, but they did not do the job in this case. Any other ideas?

thanks, Ray