Peter and I are renovating a Surfside
trailer and we used Rustoleum Topside to paint it.
We tried both thinned and not thinned. We preferred the way it rolled when thinned and used 5% mineral spirits as recommended on the can.
Following the advice we found on the Amazon.com reviews, we used a brush only for the edges and used a foam roller everywhere else. This worked quite well although a bit frightening at first! The paint 'bubbles' quite a bit as it is rolled on, but then it levels out and the bubbles disappeared. We sanded between coats and did 4 on top and 3 on bottom. Initial coats looked a bit like orange peel finish but each additional coat (with sanding between) came out smoother and smoother.
The paint gets very hard . . . over time. I tested it in an inconspicuous location and found I could still dent it with a fingernail after several days, but it was much harder by the end of a week, and after a few weeks it was almost impossible to dent. So be sure to give it time to 'cure' after painting.
We used ~6 quarts of Topside. We also used 2 quarts of the Rustoleum Marine Primer before switching to Topside to finish. We made our initial purchase on Amazon.com before finding it on the shelf at our local Ace Hardware store (call and check - only some Ace stores carry it).
We are happy with the results. It isn't super smooth like an automobile paint job. But it looks very good and we like the idea of being able to do a touch-up whenever we need.
--Lynne (and Peter)