3M Primer 94 Pen is used to promote the adhesive of 3M tapes to surfaces like polyethylene, polypropylene, ABS, PET/PBT blends, concrete, wood, glass, metal and painted metal surfaces. The bonding surface must be clean when using the primer pen. If the surface is contaminated it should be cleaned with a 50/50 isopropyl alcohol and water mixture. You should also use a clean lint-free cloth to clean the surface as well. To apply the product, shake the primer before using. Then apply a thin uniform coating to the bonding surface by using the minimum amount that will fully coat the surface. The primer must dry before applying the tape. It typically takes 5 minutes at room temperature for the product to dry. It is important for the primed surface to dry before applying the second coat. The primer can be applied using a brush, swab, pressurized flow gun, knurled roller, or a similar type of application equipment.