Repair old foam boat

[sco907]

Hello, brand new to this forum, it was the only one that I could find that had much of anything posted about foam boats (http://messing-about.com/forums/topic/8423-a-foam-boat/, most seem to not like it). I have come into a free solid core foam boat, i.e. left at side of road with free sign. It was apparently a sailboat somehow. It is pretty small, maybe two people, about 3 foot beam, 10-12ft long. It appears to be entirely made of some quite solid foam encased in a thing flexible plastic shell made of two parts, a liner and an outer shell. The outer shell has been ripped badly on the bottom in a big section. I would like to repair this so that the foam does not get worn away quickly, as it surely would. My idea was to use truck bedliner to spray on the exposed foam. Does anyone have any thoughts on that/ alternative ideas? 

This boat looks pretty ideal for my use which is not demanding, just something to drop in the water and paddle out a bit with my dog, basically a foam canoe that I can lift on my own. I will simply be throwing it in my truck bed (worked well picking up from side of road) and carrying it down to drop in the water, long term if I like it I would perhaps build a bicycle trailer for it, like some of the kayak bike trailer builds you can see online.

TLDR; Can protect the bottom of solid core foam boat with truck bedliner or is there a better coating? All I require is basic functionality, with an eye towards durability (as much as is even possible with a foam boat lol)

 

I can upload pictures later when I take some if there is interest.

[PAR]

Welcome to the forum.

 

It depends on the foam and the truck bed liner formulation, but there's a probably the truck bed liner will likely attack the foam. Maybe you can post some images, as it sounds like this might be a rot-mold build. Most of these boats are a polystyrene or polyethylene shell, filled with foam. Some of these are "cross linked" and can't be welded, but other formulations of these plastics can and this is the usual repair for this type of boat. Of course, this assumes this is what it is, which is difficult from your description. Some, including myself have had some success with epoxy repairs, but these two plastics are some of the toughest to bond to.

 

Simply put, truck bed liner is a coating and you seem to be missing some portion of the skin or it's damaged. If the boat is what i think it is, the foam is a core and the skins, in concert with the core provide the hull's stiffness. Damaged or missing sections need to be repaired, to return strength and stiffness (even if it's just locally oriented), which a gooey, extra thick paint coating isn't going to provide.

[Barnacle]

I repaired just such a boat. It was a "Mayflower"  made by the same people that made the "Sunfish" I think.   Snark?

 

Anyway, the top half plastic was still good, so I stripped away the lower half, and covered it with fiberglass.

HERE IS THE TRICK!  After I stripped off the plastic, I covered the styrofoam with Vis-queen plastic. The Vis-queen protects the styrofoam from the fiberglass resin. I think I made a paper patern of the bottom of the boat, and transfered that to my plastic. Then I put it together with wide, clear plastic tape. You might use some spray adheasive to hold the plastic to the hull, if you can find any that is approved for styrofoam. You are basicly using the hull as an interior mold, and you have to use great care and a lot of sanding not to get a rough finish.

I had a lot of fiberglass experence before I tried it. This is not a project to be taken lightly.

 

But I loved that boat.

 

Ps. this method would propably work on something like the Hottub...

[Chick Ludwig]

You could use epoxy resin. It won't attack the foam so you won't need the plastic.

[Barnacle]

A thick coat of Latex paint might also work. But I haven't tried that method.

[Chick Ludwig]

Yes, the latex paint will work. I've used it in the past.