Will they survive wet weather?
There's a discussion about waterproofing etc here, in the SpokePOV Forum on ladyada's site.
Here is someones feedback from when they were using it:
"The contacts and components will corrode. You will need to waterproof it."
There are a few different answers for different variations on this question.
Q: Will they survive a rain shower if they're outside and off while I'm inside at school or work?
A: Sure! Nothing on the PCB isn't waterproof, with the exception (possibly) of the switch, and switches which are sealed are available. Make sure the battery cases don't hold water. It would probably be best to replace the switch with a jumper in this case.
Q: Will they survive a hit from passing a sprinkler while powered on? What about saltwater, which is conductive?
A: This probably won't cause lasting electrical damage. I doubt that they'll continue to work while this is happening, but the low voltages everywhere mean that nothing is going to be arcing too badly.
Q: I like to ride on the beach, sometimes in the ocean. I do it every day. My bike frame crumbles in my hands, but I'm OK with it. Will my SpokePOV be damaged by this use?
A: Um, yes. Components on the PCB will corrode, like other metal objects, when exposed to water. If this is the case, or you'll be riding in the rain often, consider applying a clear conformal coating to your board. They're available both as aerosol sprays and in pens. Make sure that you pick a clear one, or your LEDs will be dim! You might also test a polyurethane clear coat, typically used in wood finishing, if you don't want to order conformal coat.