EkoPrime is a single-part, water-based primer designed for use on metal, composite, fabric, wood, vinyl, and many plastics. EkoPrime is primarily designed to provide very effective corrosion resistance for steel and aluminum surfaces and to create an excellent surface for EkoPoly Premium or EkoCrylic to adhere to. The sandability of EkoPrime is exceptional and it can normally be sanded 30-45 minutes after application. EkoPrime is also very flexible and may be used on fabric over EkoFill for the purpose of additional filling and sanding or to provide a light base color for bright colors.
EkoPrime is an excellent product for priming bare metal on steel tube fuselages as well as properly etched aluminum airframes. Steel tube fuselages should be also be top coated with EkoCrylic for maximum durability. It is acceptable to adhere fabric to EkoPrime using EkoBond.
EkoPrime is a wonderful product for home builders due to the ability to pour it directly into the paint gun, spray small parts, and pour the remaining product back in to the can. As with all Stewart Systems products, the paint gun is then cleaned up with water. One limitation to EkoPrime is that it is not resistant to solvents. Lacquer thinner, MEK, or auto gas will attack it. If the primer will be left exposed in an area where it may come in contact with solvents or fuel, EkoPoxy would be a better fit.
EkoPrime is available in four colors: white, smoke grey, charcoal, and zinc chromate green (tinted to simulate ZC primer and does not contain zinc chromate).
Which primer should I use? (PDF)