The main difference between Rustoleum Rocksolid and Dymark epoxy kits is the type of epoxy they use. Rustoleum uses a two-part epoxy system, while Dymark uses a single-part epoxy. This difference in the type of epoxy used means that Rustoleum will offer a stronger bond and is more resistant to the elements and wear and tear.
Additionally, Dymark epoxy kits are not as durable as Rustoleum.
Epoxyshield is also made by Rustoleum and is similar to Rocksolid in that it is a two-part epoxy system. It is is more flexible and offers more protection from the elements that Dy-Mark kits. In addition it is also more durable and offers a stronger bond than Dymark. It is also resistant to heat and chemicals, making it suitable for a variety of surfaces.