What is the best way to prep for use over Dicor's 501LSW lap sealant around vents, skylights etc.?

Question

RV has multiple vents and they were sealed with Dicor's 501 lap sealant.  I just purchased 7 gallons of RV liquid roof and I want the material to be compatible and not come up around these vents.  So far I've gotten three answers that conflict.

Answer 1

Hello The Dicor Lap Sealant contains some solvent so it is not good for filling such a void.

A better method is to fill cavity with spray insulation foam;  seal the end with Butyl Tape and coat over Tape with Liquid Roof.  A Universal Repair Kit has everything needed except the foam.