Said to be safe for use on all aircraft alloys, stainless steels, aluminum alloys, magnesium alloys, carbon steels, cadmium-plated steel and titanium alloys, EFS-2500 is a waterborne aircraft paint stripper designed to replace hazardous methylene chloride-based stripping chemicals. The chemical contains no chlorinated components or carcinogens, is environmentally friendly, non-toxic and biodegradable and does not cause hydrogen embrittlement of aircraft alloys, according to developer Molecular-Tech Coatings Inc. (M-TC; Maple Ridge, BC).
The company says EFS-2500 is also applicable for stripping automotive, building and other coatings. It is said to work on surfaces including brick, cement, ceramic, concrete, fiberglass, masonry, plaster, stone, wood, furniture, gelcoat and paint film.
Developed after extensive testing on painted exterior surfaces of commercial aircraft and military helicopters, the compound contains no methylene chloride, formic acid, carbonic acid or N-methyl pyrolidone. Ingredients used in the formulation comply with U.S. Environmental Protection Agency rules on emissions, and the product is said to fully conform to Boeing D6-17487M specifications. M-TC says wastewater from stripping met requirements for discharge into storm sewers (pH 6.5–8.5) or municipal treatment works (pH 5.0–11.0) as specified in the British Columbia Waste Management Act.
The chemical is said to efficiently remove several layers of aircraft paints, including epoxy primer and cross-linked polyurethane top coats. It’s also applicable to remove top coats containing high-solid fluorides and polyurethanes, and is effective for softening and removal of aircraft adhesives.
The stripper works by breaking the bond between the substrate and primer, leading to a secondary action which causes the paint to lift off the surface as a single film that includes the primer and top coat. Once the paint is lifted, it is said to be easily removable with a rubber squeegee or high-pressure water spray.
Application is via airless spray, immersion or dip and hang. The product clings to vertical and overhang surfaces, has a long active life and slow evaporation rate and can keep lifted paint moist and pliable for well over 24 hours, the company says. Paint lifting can be accelerated by elevating surface temperature to 85°F.
One gallon of material is said to cover 80–100 sq ft of surface depending on thickness of the paint film being lifted. The product must be applied approximately twice as thick as the layer(s) of paint to be removed.