Opinion on foam core

[SS MAYFLOAT]

On my 27' I have just about finished with re-glassing the area where my fuel tank lays. First let me explain the secenerio. Under the fuel tank (which is 8' long) has 1/2" plywood. Next under the plywood are stringers that are about 8" on center and are only 2 1/2 inches high. So this leaves me with 8 spaces of dead air space that are 8'x6"x 2 1/2". At the ends of these spaces it is sealed off. This is the way the boat was manufactured. All other spaces have been filled with foam core except for these spaces under the fuel tank.<br /><br />So my question is this "Should I foam core these areas? With these areas being at the lowest part of the hull makes me leary of these areas eventually water logging the foam core. Then another opinion from a fellow boater suggested that at the ends of the spaces (which would be located in the bilge) to drill holes in each one of them and epoxy in a sleeve for a drain plug. Then after use, pull the plugs every once in a while to check for water leakage. This seems to be the way I wish to go. These 8 spaces each would work like water tite compartments. If I did get a puncture to one of them while it is in the water, at least the boat wouldn't sink. With the drain plugs being installed, it would then help me isolate which area has failed.<br />Thanks for any input..SSM

 

[Hawkeye1]

Re: Opinion on foam core

I like your drain plug idea.

 

[crab bait]

Re: Opinion on foam core

i don't know if this helps but the different things i read says NOT TO FOAM IN A TANK. it'll cause condensation in a major way to fuel..but that's think is when folks lay down expandable foam then set in tank usin' foam as a bed.. to drill holes an plugs,,,,,, sure why not..... just make sure you use epoxy...

 

[Spidybot]

Re: Opinion on foam core

At least you wouldn't want to use foam in a way that it'll get in direct contact with your tank as it you'll never get the tank out agin.<br /><br />I'd go for the plug & drain solution. It's even easier...

 

[SS MAYFLOAT]

Re: Opinion on foam core

Maybe you didn't understand me. The fuel tank sits directly on the 1/2" plywood. It is not foamed in nor do I plan to foam in the tank. The foam I am asking about would be located in the 8 cavities between the plywood and the hull. Again each individual cavity is roughly 2 1/2" x 6" x 8'. These spaces or cavities run length wise of the boat. Does this help explain things further?<br /><br />Thanks again....SSM

 

[crab bait]

Re: Opinion on foam core

sure does... that 2 part foam is high dollar.. but better than an air space for floatation.. if breeched...

 

[evin300]

Re: Opinion on foam core

SS MAYFLOAT, I like the drain idea too, It will be a good way to monitor for leaks.<br /><br />I must share with you what happened on my one and only floor, transom and stringer job. First of all, yes, I had rotten wood, and I assumed that it must have come from the boat sitting outside in the rain. (there were a couple of abandoned screw holes in the floor etc.)<br /><br />When I put the new floor in, I glued plywood pads to the floor glass with 3M 5200 and mounted the seats etc. to these, as to not have any floor penetrations.<br /><br />However, I ignored the gelcoat chips on the outer bottom of the hull, and a 2" x 2" area of gelcoat missing at the keel where it meets the stern. Well guess what? my foor cavity got wet again! I later found out, that water will wick through the exposed fiberglass fibers.<br /><br />This is just a Heads-Up, as I dont want you to be as dissapointed as I was, after all of that work. Good Luck, and thanks for the compliments for the chainsaw idea, Mike