I'm considering buying a Bluberry Buzzsaw and wanted to understand something about the coverstock. It is referred to as a reactive urethane coverstock. Is this the same as reactive resin? I'm used to differentiating between reactive resin and urethane, but I'm not sure what is meant by "reactive" urethane, can't tell if this is normally what I think of as resin or urethane, or something completely different. This may be a dumb question, but any help would be appreciated.