Cleaning Excess Butyl from RHT Roof Shells. Butyl adhesive is used to secure the seals of the retractable hardtop (RHT) to the steel roof shell panels. Particularly at high ambient temperatures, if excess butyl is present, it may start to seep out from between the seal and the roof shell. This butyl may be black or gray in color. Excess butyl applied to the roof shell during assembly
