Hi Kevin please see below. the product can go directly over pin holes
Preparation. Although light rain can directly fall on the Butyl Liquid Rubber 2-3 hours after it has been applied (assuming temps above 60°), we suggest you plan a day when rain is not in the forecast. Butyl Liquid Rubber may be applied at any temperature above 50°, but we suggest between 55°-80° for best results. Butyl Liquid Rubber needs a temperature at least 55° for the product to cure. Many people have asked us if they can apply it below that temperature. The answer is of course, "YES", but the curing process won’t commence until it is above 55°. Assuming you have a smooth surface that needs to be coated, the coverage per gallon is approximately 50 square feet. For rough substrates, the coverage is 40 feet per gallon. An example of a rough substrate is BUR (built-up roofing). After you have completed the application, we suggest waiting approximately 24 hours before walking on the surface. It will develop a skin within 2-3 hours. For any separation in the joints, we suggest filling them with Rubex caulk found on or order form. This caulk has been field tested and is compatible with Butyl Liquid Rubber and will not void its warranty. It is free of any solvents or isocyanates and is 100% volume solids.
Any rips in seams or spacing more than 1/15 of an inch, we suggest reinforcing with either poly-fabric or butyl two-sided tape. Both are available on our order form. Any holes, gaps, seams or tears (of more than 1/16-inch) should be repaired or reinforced. Rusted areas on your metal roof need to be brushed with a wire brush to remove as much of the oxidized rust as possible. Any light corrosion that is not loose is fine for applying Butyl Liquid Rubber over. For heavy rust, a rust inhibitor is suggested prior to coatings with Butyl Liquid Rubber.