I am an artist, not a sign maker. But my kids charter school asked me to create an outdoor sign which I did using a sheet of plywood (with a finished side). I painted the heck out of it--primed, multiple layers of paint and then of course handpainted the logo. I used outdoor paint from Sherwin Williams. I finished the edges of the sign with a vinyl J trim. You can stop laughing now That was my big mistake. Of course a year later there is water damage. The plywood all along the lower edge of the sign is admitting water and the paint along the lower edge is bubbling. What is the recommended product to finish and seal the edges of an outdoor wood sign? I want to fix it! I am looking at "backhand trim" at my local lumber yard but don't want to make more mistakes. Please send your advice! Thank you in advance.