trs80 wrote:
I have about a 8' x 4' skylight with opaque white plastic dome. It
has 3 cracks radiating out to about 1'. its intact, just cracked.
Probably the wind blew a pine cone into it.

How can I go about repairing it? The dome is not viewed from inside
the house as there is a colored glass inset in the ceiling. I was
thinking contact cement and laying a flexible membrane over the
cracked area that would withstand the weather and UV. I visited
Lowes but saw nothing like that. It would be great if the membrane
was translucent but not critical. Any hints appreciated on how to go
about this repair. thanks!

You've had good advice from other posters. If the dome is aged, sunlight has
done it's best. Ditch it and replace.