From   www.Spartantrailer.com  (interior restoration)

Before any refinishing was done all leaks in the trailer had to be sealed. I used a liquid seam sealing product called Capt. Tolly’s. This is a marine product which has a capillary action by which it draws itself into the crack and hardens. Vulkem 116 Sealant was used for larger seams.. Another option is to coat the interior with a gas tank sealer such as POR-15. to create a water tight seal.

This post is part of a series documenting Sam Breen’a Spartan Restoration Project. Please see his first post here and check out the archive here. The CSPA is helping Sam by serving in an advisory role, offering modest support and featuring Sam’s Progress by syndicating his feed from http://spartantrailerrestoration.wordpress.com as part of our CSPA Supports Program.