I'm assuming your talking about the clearance lights, not the porch lights? I had the front top red clearance light almost lose the lense, there's no noticeable sealant on mine. Or at the very least there's just a dab to hold the lens in place, until it doesn't.
2014 Redwood 38BR, Fulltiming
2013 Ford F-350 CCSB 6.7L 4x4 SRW, B&W Companion Hitch, Air Bags