Black Rubber Speaker Repair Glue L3045 is formulated to meet high performance, durability and industrial requirements geared towards the loudspeaker industry. Its fast setup and medium viscosity are ideal for attaching surrounds of almost any composition to cones Also works great when attaching dust caps. Surface should be clean, dry and free of dirt. For best results, lightly roughen surface before use. For dust caps we recommend scuffing the lip with sand paper. When gluing surround to frame first apply glue onto the frame and let it air out for a minute. Then apply surround and press firmly onto frame. Fixture cure time is 10 minutes. The softening point for this glue is 230° F and max temperature resistance is 250° F Once applied it usually tacks up in 4 minutes and allowing for plenty of time to make any adjustments needed before parts fully cure. Allow 24 hours for curing. Depending on materials and temperature, maximum strength may not be reached for 48 to 72 hours.