Floor - underbelly coating

[JeepThing]

OK so Thanks for all the advice!, I have finished coating the bottom using Henry's asphalt evil smelling black goo. After talking to several different people at the Big Box stores both in Canada and across the boarder it seams most agree that the white Elastomeric Roof Coating does not adhere to the wood as well as the evil black goo, problem is if it ever starts to peel off it could come off in large section as it creates a continuous membrane. That was enough to scare me away from that idea. Your right tried and tested works best. I'm not about to re-wright the book on this. So thanks to all for your input.