Byk -315 Polyester modified poly-methyl-alkyl-siloxane BYK Chemie Flow / Levelling agent >> Silicone Coatings >> Solventborne Automotive OEM Automotive refinishing Methoxypropylacetate / Phenoxyethanol 1/1 Byk® -315 is a solution of a polyester modified poly-methyl-alkyl-siloxane. BYK®-315 is a silicone levelling additive with only slight reduction of surface tension. It is especially designed for usage in automotive coatings. It improves flow and leveling as well as increases gloss. BYK®-315 does not show blushing in clear coats after water immersion tests. Solution of a polyester modified poly-methyl-alkyl-siloxane. Used as a levelling additive for automotive coatings. Provides a slight reduction of surface tension. Improves flow and levelling. Increases gloss. Does not show blushing in clear coats.