Flashing your glue for tub surrounds

If you use a solvent based adhesive and squeeze it between two surfaces that will not let the solvent out -- like between tiles and the vinyl -- then the solvent will eventually eat into the vinyl showing up as a ghost line of the glue. Put a trace of glue on the wall. Push the vinyl panel into it and then pull it back. It will leave an exact copy of the glue line on the vinyl. Leave it open like that, without moving the panel, until the glue gets tacky. Then push it together. We call that flashing the glue, or more correctly letting the solvent flash off.