I may have made a mistake. Had about 15 to 20 CertainTeed Sealdon 25 Organic Asphalt shingles that had not sealed properly. They have been on for almost 10 Years. Some of them the whole tab and some just at the corners. I used Dap Watertight Asphalt Sealant to hold them down instead of a asphalt cement. Will the Sealant work or will I need to redo what I have done? I called DAP Customer Service and was told their product should be ok for repair of just a small number of shingles but not recommended for complete installation. I haven’t told my wife yet and sure hope I won’t have to tell her that I goofed badly.