We have an full EPDM flat roof where the rain drains to metal scuppers. Due to the construction style, there’s always a little bit of water sitting at the base of the scupper entry area (about 3/8”)” of pooling. Over the years, many sealants have been tried and failed at the scupper seam where it meets the EPDM. Most recently we used Henry 209XR last fall but it does not work well ( we see some lift already) and to make matters worst, a representative from Henry stated that their product will damage EPDM rubber over time on a Q&A on the Home Depot website this month (contrary to their TDS which we referred to before proceeding to use it). I purchased a gallon of Liquid Butyl hoping to resolve this issue once and for all. Do you know of any issues applying this over Henry 209XR? I’m not sure if we can 100% scrape that stuff off the areas we applied. I read that the Liquid Butyl will adhere to metal without the primer so we didn’t order any with our Liquid Butyl.