Hi-Mar DFC-21 Nonionic oil-based Thornley Company Defoamers / Anti-Foaming Agents ADHESIVE Water dispersible nonionic oil-based defoamer for adhesives. It provides quick knockdown of foam and excellent persistence as well as defect free films. Water dispersible nonionic oil-based. Used as defoamer for adhesives. Provides quick knockdown of foam and good persistence as well as defect free films.