We have an epdm roof with a metal scupper. We had to to use Dicor Lap Sealant at the seam where the epdm meets scupper. Can we use Butyl MS Caulk over the existing Dicor Lap Sealant? The goal is to cover the Dicor Lap Sealant with the Butyl MS Caulk at the seam first, then eventually use the Liquid Butyl over it for a seamless finish and seal it in completely.