Our coach spends a lot of time parked in front of my shop with the bedroom slide facing due south. When I rebuilt the auxiliary compressor I taped over both slide reveals just in case there were problems with the rebuild and it rained during the process.
Looking at the applied painter's tape brought to mind the great potential for the black bladder to suffer UV damage and fail, so what I'm planning to do now is get some white or light colored foam weatherstripping of the right size that I can force it into the crack and protect the bladder from UV while it's parked here.
Can't hurt............right?
I would wipe it with 303 uv protectant.
I used it on my tires, airbags, decals and dash in the coach and my cars for the last 15 years.
It's a non petroleum base product so it seems ok to use on tires. Plus it looks nice.