Originally Posted by dmhenderson

Tip I came up with that I figured I might pass along to folks doing these themselves who worry about condensation:

Buy this stuff:
Amazon.com: Rust Oleum 274232 Never Wet Multi Purpose Kit: Home Improvement

Now buy this stuff for good measure:
Sonax 223100 Black Polymer Net Shield : Amazon.com : Automotive

My lights have been opened about 4 times now and have pretty significant heat warping along the seams. After you re-seal the lights with butyl, apply 2 coats of "never wet" (drying in between coats) along the seams of the lights. Once dry, apply a coat of the polymer net shield. Drove around a bit in the monsoon we had in DC last week and both lights are dry as a bone.