I watched this video, and I cringed about all the foam they seal into the hulls and stringers of boats these days. It's great when new, but if water does get into this foam, it's not going anywhere. My recent project has shown me that.
Here's where I break into a sealed compartment in my 1996 Sprint Fiberglass boat and "find a lake".
My stringers were rotten too, and they are supposably sealed as well, but nothing is really sealed. Water gets everywhere, and that foam just acts like a sponge, once it enters into that foam, it is there forever! The absolutely terrible thing is, to inject the foam on my boat, they drill a hole. And they did not even attempt to seal that hole up. So every drop of water that sank into it, was still there.
I'm still watching this guys series of videos about his bass boat getting built. I wanna see if they seal up those foam injection points in that boat. I will see.
I just seen where they cut the foam where they sprayed it on the bottom of the cap compartments, before seating the cap. All I see is that they unsealed that foam by cutting into it, and made it more sponge like!
Yes I'm ranting again, but foam holds water. They need to come up with a better solution.
I know this is an aluminum boat, but it's shows how bad foam is once it gets wet:
And yeah, you can seal fiberglass, but can you guarantee it's sealed, cause water gets everywhere on a boat, after all, it's a boat.