Hi all new to Tin boats and I got a question. I took my Sylvan Aluminum 14 foot apart this week to tackle the 'sinking' issue I've been having. I found a bunch of rivets missing and leaking in the front and fixed those. In the back water enters from under the transom where the two pieces of aluminum join. I've removed the entire transom and now i'm ready to put it back together. What I would like to know is can I use Butyl tape to form a gasket between the two pieces of aluminum prior to riveting? If not butyl can i just use 3m 5200?? I would like to do this only once as the neighbors are getting mad at all the banging and cursing. Thanks and a great site you have here.