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Tuesday: 40F, heavy overcast, gales and rain. I shall have to tie down the dome again! Another excuse for working on the telescopes. Or not. It was noisy, draughty and cold up there!
I clamped a laser level onto the dome to see if there was any movement of the red spot on the observatory's far wall. There was, but not much. Mostly slight rotation in fiercer gusts. Little obvious lift. At least, not according to the optical leverage available over this distance. [About 10' or 3m] I decided to play safe anyway and used two ratchet straps to tie the dome down to the massive pier.
With the shutters facing the prevailing wind [SW] there was a fair bit of rubber skirt flapping just below the shutters. Perhaps I should double the skirt just there? It is a short, separate length. The more continuous skirt, on the rest of the dome, is under geometric tension from the nearest sides if it tries to lift.
Brief glimpses of the sun do not tempt me to open the dome in this wind! Normally I'd be out there like a shot! Besides, there are frequent, short showers as well.
The aluminized, foam camping mat has arrived. It looks very smart and practical for DIY dewshield use. Talking of which: Shiny aluminium would reflect the sky and nearby trees. Suggesting, to me at least, that it would be less visible, from a distance, than a snow white dome.
Would space blankets work to hold solar heat away from the dome? The lightest survival blankets are quite inexpensive. Only one half of the dome needs protection from the sun. Could be doable, but what about the active lifetime in all weathers? The shutters are more easily covered than the trapezoidal panels. Staples?
There might even be a small increase in waterproofing if the material sheds the rain effectively. However, I can imagine it will flap wildly in the wind with being so thin. Can it be tensioned enough to stop it disintegrating? Tape rapidly become expensive, even from just taping the edges over a large area.
Covering only the shutters has double the value. Or even triple. They would be much cooler when closed in sunshine. When open they shield the dome with their own shadows. If they are also cool from reflective materials, then they have even better value. Cool shutters mean cooler shadows from reduced radiation passing through the shutters to be absorbed by the obscured panels behind them.The panels, which are outboard of those which are shaded, are at a much greater angle to the sun. Meaning less heat absorption. Drawer slides could provide double width shutters on added crossbars. Or the shutters could be made wider to match a wider observation slit. Major work!
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