I first over hauled my trailer and then I did the steelflex. Turned tin upside down, painted the hull and up sidewalls a couple of inches with steelflex. Once tin was turned back right side up I then painted inside and out covering everything except the hull. I even carried the finish coat down 3 feet on the front of the hull so now you can't see any steelflex. I thought these steps was better so once I finished with the final coat I did not have to handle the tin no more. Final coat was done on my trailer.
https://www.tinboats.net/forum/viewtopic.php?f=21&t=14366