Replacing soaked poured in foam

[davidj65]

Started to do a DC install, pulled the deck and the bottoms of the plywood were just laying on wet foam. Some much worse than others, but all of it is wet to some degree. Mercifully, most of the marine plywood(at least that's what the label says) is fine. A lot of recent surface mold, and superficial rot around the edges that's probably been happening for a while. I'm the second owner, and I think the first owner kept in in a berth on a private lake in PA all summer, so it saw a lot of rain.

The foam installation by Alumacraft really doesn't seem so well thought out. I know nothing about this but my own common sense, but it seems that foam that absorbs water is a stupid design decision. And why they would enclose the foam in the pods in a plastic bag, no idea. Just filled with water and sat there. The foam on the floor is installed in all the framing crevices and drain points, so when water seeped between the gunwales and the edges of the floor, it had no way to drain, just seeped in-between the bottom of the floor and the foam and just sat there. Ticking time bomb

I found this by accident and if I had more experience, I probably would have known to check it as soon as I bought it last year. It is not a big deal, major pain to remove the foam but it will save the floor and I'm glad I caught it when I did.

I'm planning on replacing the soaked foam with blueboard wall foam insulation, leaving the drain channels open. I have heard that the poured in foam between the ribs provides hull rigidity. How critical is that? The floor is screwed into the ribs pretty thoroughly.

Thanks for the feedback.

 

[Tin Man]

Looks like you have a Alumacraft V14 or V16. I had a 2017 V16 and did a few mods that you can search for on this forum. My foam was in good condition. Like you said, not such a big deal to replace, just takes some time. Great boats BTW! Sitting in the rain definitely caused your issues! Mine was garage kept (by me and previous owner) so no issues about water intrusion into foam/decks.

I believe most small tins and small fiberglass boats used this same foam, I believe even Boston Whaler. I believe this type of foam is used for buoyancy, rigidity, USCG regs, ease of use in production, and cost. If you can keep it garaged, I would replace with same and in same locations. If not, and boat will be left outdoors in the rain, research best type of foam for replacement for this application and use a high quality cover made of Sunbrella. Not sure I'd call it a bad design, and when taken care (out of rain), the foam can last for decades.

When I was learning and researching my V16, I ran across this guy who COMPLETELY tricked out his V16!!! Over 20 chapters on various sections of his build. Great ideas if you own a V16 and want to mod it.

https://www.youtube.com/@ricardasbubulis3944

Good luck and enjoy a great boat!!

 

[Tin Man]

IMO....If you plan on changing to a different type of foam, I would check on buoyancy, weight, USCG approved, etc. per cubic foot for the type of foam that came with boat from factory and any replacement foam. Apples to apples comparison.

 

[davidj65]

IMO....If you plan on changing to a different type of foam, I would check on buoyancy, weight, USCG approved, etc. per cubic foot for the type of foam that came with boat from factory and any replacement foam. Apples to apples comparison.

It is a 2017 V-14, and I do like it a lot. I don't have the option to garage it, but I cover it when it rains with a good cover. Not sure what kind, but it wasn't the hundred dollar one.

For the moment I will probably install blueboard foam in the floor. I just can't see installing another pour/spray foam deal that blocks all the drain channels and locks up the water. I really don't get that design idea at all. Plenty of people park their boat at their summer camp lake for a few weeks or more, it's not crazy to expect that water is going to get under the floor. My concern with loose blueboard foam is hull rigidity, and how much the factory foam relies on that. There are lots of tin boats with no floors at all, just ribbing, no? The floor is 3/4" plywood and still very sound, the mold is superficial.

Thanks for all the info.

 

[lightflyer1]

My foam is up under the seats and doesn't touch the floor, keeping it from getting water logged from sitting in standing water. I believe the previous owner kept it garaged and I keep it covered with a heavy duty tarp with pvc supports. Seems to be working well for me so far.

 

[FuzzyGrub]

It is a 2017 V-14, and I do like it a lot. I don't have the option to garage it, but I cover it when it rains with a good cover. Not sure what kind, but it wasn't the hundred dollar one.

For the moment I will probably install blueboard foam in the floor. I just can't see installing another pour/spray foam deal that blocks all the drain channels and locks up the water. I really don't get that design idea at all. Plenty of people park their boat at their summer camp lake for a few weeks or more, it's not crazy to expect that water is going to get under the floor. My concern with loose blueboard foam is hull rigidity, and how much the factory foam relies on that. There are lots of tin boats with no floors at all, just ribbing, no? The floor is 3/4" plywood and still very sound, the mold is superficial.

Thanks for all the info.

I understand Tin Man's point, but on the other hand, new blueboard is more buoyant than old waterlogged foam. If you hadn't checked, you would be under a false security, thinking it was good.

 

[davidj65]

I understand Tin Man's point, but on the other hand, new blueboard is more buoyant than old waterlogged foam. If you hadn't checked, you would be under a false security, thinking it was good.

Exactly, and the floors would have rotted. I plan on installing as much Styrofoam as I possibly can.