My girlfriend has a canoe that hasn’t been used in about 10 years, we decided to use it, so I patched some small holes and took it apart to clean it and in the front and back point of the canoe there was foam to the shape of the canoe, behind a screwed in piece of plastic, is that necessary for the canoe to be usable?
If the canoe is made of fiberglass or solid plastic like polyethylene it is heavier than water and will sink if fully swamped. The foam is referred to as flotation to prevent that. Some fiberglass boats have air tight tanks that serve as flotation.
Some plastic boats look solid but are constructed of a multi-layer sandwich with a foam core that looks like swiss cheese. This type of material is lighter than water so such boats don’t require supplemental flotation.
Shoor it be useable…
But since dats flotation, yer canoo might sink ta de bottom iffin' it tips over. Ah's reckon yer canoo be aloominiooom or fibberglas? (dun't recollect iffin de Coleman's had plates over de flotation.
so it isn't necessary? The canoe is planstic but it seems like only one layer. Your answer was very helpful though.
The canoe was plastic, but the foam was cockroach infested and half eaten.
just for temporary extra floatation …
… consider tying an old auto inner tube (blown up of course) under the yoke (thwart) in the center .
That way you got some extra floatation while you think about replacing the original (real) floatation in the stern and bow holds . That stuff is kinda expensive now a days but the new stuff dosen’t rot out like the old stuff did .
Having floatation in a canoe is a good idea . If you swamp it , the floatation makes a big diff. in getting emptied out an floating again . Like FE said , keeps it from going to the bottom .
You should replace it
Large blocks of foam which can be trimmed to fit are available, but I don't know where. A fairly simply alternative is to buy sheets of Styrofoam insulation at a home-improvement store (actually one 4x8 sheet, two inches thick, may be enough). Cut a series of pieces, shaped to fit, and stack them from bottom to top to fill the available space. The thicker the sheet of material you start with, the fewer the layers you will need and the less cutting you will have to do. Closed cell insulation (true Syrofoam sheets, normally either blue or pink in color) is easier to cut and shape than the cheaper stuff (normally white in color) which is made of compressed beads. The stuff made from compressed beads falls apart when you try to cut it. The price difference is minor for the amount of material you need, so make the job easier and get the good stuff.
It is flotation and should be left …
there or replaced with new.
It would help if you mentioned the make and model of the boat. That way, we could tell you how it was constructed.
If the boat has aluminum thwarts, seat frames, vertical braces, gunwales, or a keelson it might require flotation to maintain positive buoyancy even if it is made of 3 layer rotomolded polyethylene with a foam core. More likely, it is solid poly, which is usually denser than water, and again needs flotation.
Actually, just about anything that displaces water and does not become totally saturated will work. The Ethafoam type material used for packing can be used. The less expensive Ethafoam might take on some water, but you might be able to get it for free. I have seen mesh bags full of ping pong balls used also.
this is the type of stuff you want …
...... to re-fill the stern and bow holds .
Mix and pour in fast . 1 cu.ft. (fully expandeded) in each end is about what you need . Make sure it can't leak out anywhere before pouring in . Only mix up and pour in one end at a time . 2 cu. ft. of 2 lb. density foam (weighs 2 lb./cu.ft.when expanded fully) offsets about 100 lbs. of weight for bouyancy . Each cu.ft. floats 50-60 lbs. . You don't need higher density foam like 4 , 6 or 8 lb. ... those foams are used for structural purposes . 2 lb. foam is fine for canoe ends , it cost the least and expands to the greatest cu. ft. as well .
West Marine stores (if you got one local to you) should have the same type stuff , probably Evercoat brand . The stuff is called expandable polyurethane 2-part (mix A+B) "pouring" foam floatation . This stuff is not sprayable and needs to be mixed 50/50 , then poured in from the top (fast) , so plan your attack ahead of time .
Aero Marine is another brand (same stuff) ...
Wear a respirator and keep it away from yours eyes ... you don't want a drop of this stuiff to accidently go down your throat .
for all of the input, I took it out today using the same foam stuff but filled in some of the holes with expanding foam and it worked, I’ll be looking forward to taking it out again.