3M Scotchrap Pipe Prime is a quick drying, non sag rubber base primer that permeates metal surface pits and irregularities, preparing the surface for tape application. Compatible with the special adhesive on 3M Scotchrap Tapes, it enhances adhesion. To be used with 3M Scotchrap Corrosion Protection Tapes 50 and 51. 1 gallon can.Compatible with the special adhesive on 3M Scotchrap Tapes, it enhances adhesion. To be used with 3M Scotchrap All Weather Corrosion Protection Tapes 50 and 51.