Zinsser Peel Stop Triple Thick 3.78LZinsser Peel Stop Triple Thick Primer 3. 78L Stop peeling paint in its tracks with Zinsser Peel Stop Triple Thick Primer a high performance, water based binding primer that locks down cracking, flaking, and weathered surfaces. With 3x the thickness of traditional primers, it fills minor cracks and gaps to create a smooth, consistent base for topcoating. Designed for flexibility and long term adhesion, it prevents future peeling and withstands surface