On my slimed unwashed sides of my Jon boat, when I have to stick my yearly state and launch decals, I wipe clean, and peel and stick. They won’t come off without heat and a raiser blade to put the new ones on. Peel and stick 3 m is the same, clean the surface on your jon boat and stick it on without air bubbles under it. Marshrunner757 is right. When I pull my glued carpet up, I will have to really work the surface clean. That will take some elbow grease!