3M AP115 silane glass treatment is used to promote adhesion of 3M acrylic foam VHB tapes to uncoated glass surfaces. Glass is hydrophilic (water loving) in nature and may lead to performance issues over time in humid or wet environments due to water vapor undercutting the bond line and interfering with normal adhesion forces. 3M silane glass treatment AP115 treats the glass surface (acts as an adhesion promoter or primer) creating a hydrophobic surface that will Act to protect the 3M VHB tape bond line. Coverage provided is approximately 20 to 25 square feet per 4 fluid ounce bottle.