Having problems sheeting!

[b63215b]

Those of you that have been following my progress I have some more questions. So I started sealing the sheeting metal edges. I did a few test spots. I used a plastic bondo trowel to get it inside the edge. I let it partially dry the used a piece of flat stock with a ground edge to scrap up the extra. I read up says you can sand but reviews online are iffy about that. Any suggestions on better ways to do this swcruiser?

So far in not a fan seems messy and not clean at all. I am open to any suggestions. By the way it is PL premium!