If it turns out that the new version PPG Gripper is not as good as the original Glidden Gripper, this is my current top choice research candidate
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I'm looking at a moisture-cured polyurethane aluminum filled paint called Aluthane.
From a private-label coatings chemist, Paul Oman, MS, MBA -- NACE (National Assoc. of Corrosion Engineers), SSPC (Soc. of Protective Coatings) aka "Professor Epoxy"
real character but super customer-service oriented, 603-435-7199
his company called Epoxy Products.
A excellent primer, very adhesive to almost any surface, will completely encapsulate the foam + canvas like an epoxy primer
and can also be a very tough top-coat if you like the color, over a rough surface comes up shiny.
Used on industrial vehicles and restorers, water tanks, train cars, engines, bridges, boats etc. Specifically also wooden decks and floors, pilings & piers, underwater no problem.
https://www.epoxyproducts.com/dataaluthane.pdfhttps://www.epoxyproducts.com/aluthane.htmlI realize this is not a cheap product in the original spirit of Glidden's "hardware-store primer".