Filling your bilge with foam

MIKENVAHBEACH

Petty Officer 3rd Class
Joined
Apr 20, 2003
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84
Why don't manufacturers fill there bilges with foam? It seems to me that areas(particularly on outboards) that are not used for storage, cable runs, or fuel/water tanks could be filled with foam. Therefore eliminating the need for bilge pumps and the risk associated with them. I don't know if this is how Whalers are built, but why is this not done? The boat would swamp, but never sink, right? Could you fill the bilge on an older boat with foam and accomplish this? Just been think about it and wondered what everyone else thought.
 

Bondo

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Apr 17, 2002
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Re: Filling your bilge with foam

wondered what everyone else thought
Click on the red "Search" at the top of this page,+ enter "Foam".........
 

catfish1

Senior Chief Petty Officer
Joined
Jul 23, 2003
Messages
683
Re: Filling your bilge with foam

i like the fact that you are talking about foam, and not ping pong balls. :D the bilge area is your friend, you need it to accumulate water in order to be pumped out. if you didnt have a bilge, how would you get the water out? some people close(glass)the bilge area off so water cannot flow under the floor, which is ok. but you need a bilge area! by the way, whalers are built with foam within the boats hull, thats why you can cut one in half and it wont sink.<br />you mentioned cable runs. yes, you can foam the cable runs. just use pvc pipe for cables to go through. i am toying with the idea of doing that myself, although it is a pain in the rear to remove the top half of the boat, just to pour foam in it.
 

JasonJ

Rear Admiral
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Aug 20, 2001
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4,163
Re: Filling your bilge with foam

I foamed the entire under floor area on my project except the center bilge. That way any water that makes it in has this center bilge to collect in, and it can be pumped out, rather than just festering in with the foam and eventually soaking in. I have enough foam where my boat cannot sink (yeah, we've heard that unsinkable thing before). Just use a good 2 part foam and be done with it. There are a lot of interesting alternative ideas out there, but the foam still works the best or the boat manufacturers wouldn't use it. Good luck...
 

MIKENVAHBEACH

Petty Officer 3rd Class
Joined
Apr 20, 2003
Messages
84
Re: Filling your bilge with foam

Catfish, <br />I know it gives me an area to collect and pump out water, I guess my thought is, if the entire bilge and all void spaces in general on my boat(or any other for that matter) was completely filled with foam, then there is no place for water to collect, at least inside the hull. A closed system of sorts, that prevent the intrusion of water to begin with. <br /><br />I have a 1989 22' 2200wa Pursuit w/a 2004 bf225 Honda and a 2004 15hp honda 4-stroke kicker, these motors are much heavier than the original motor. Currently, my boat sits alittle lower in the water, about 1" lower than it did previously. Its not much of a problem when inshore fishing, but I'm looking to take her relatively far offshore(20-40nm) and I would love to enhance its construction aswell as give it that "unsinkable thing" Jason's talking about. <br /><br />Last week, I had four big boys on board(each weighing in excess of 350lbs) and when they went aft I had more water in the engine transom well than I would like, it flooded and spilled over into the cockpit. I was right at the maximum combined weight limit(engines+gear+guys) indicated on my boat 2500lbs. The bilge stayed pretty dry the entire time, I have two bilge pumps and neither one of them ever pumped water. I know my boat is self bailing and when underway the water drains out nicely, I guess if I did'nt have to worry about the possibility of the bilge filling with water it would be one less thing to worry me when I'm far offshore. <br /><br />JasonJ,<br />I read thru a few of your posts and it sounds like a pretty intensive process. Good job by the way! I think, for my boat, there might be many places within the bilge that might not fill with foam properly or even worse cause a floor or hull blow out. Can this 2-part foam be added into a boat that is not disassembled? I currently have no other reason to tear the boat apart. Not saying that I would'nt just trying to get some opinions.
 

Bondo

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Apr 17, 2002
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71,088
Re: Filling your bilge with foam

Adding Foam will NOT make your boat Float Any Higher..........<br />It'll Actually be Lower in the water.....
 

catfish1

Senior Chief Petty Officer
Joined
Jul 23, 2003
Messages
683
Re: Filling your bilge with foam

i dont think i am understanding you correctly. do you have a leak in the hull? your last reply leads me to believe you do. and also when you say foam the bilge area, are you refering to the stern bilge, or are you refering to the center part of the hull from bow to stern?
 

JasonJ

Rear Admiral
Joined
Aug 20, 2001
Messages
4,163
Re: Filling your bilge with foam

I applied my foam after the floor was installed. I elevated the bow and poured the foam though a series of 2 inch holes between each stringer, starting at the transom. When the foam got to the hole I put the plug in and placed a weight on it until it stopped expanding. I worked my way forward, mixing 1 cup of each part at a time, and waiting until expansion stopped before adding the next batch. This prevented blowout or bulging, but ensured the entire void was filled.<br /><br />If the boat sits lower with foam it will not be by much, as the foam does not weigh very much. If the proper amount is used in the way you are thinking, it will keep the boat from swamping. If you are rebuilding the floor and the floor is not above waterline, you could always build it above waterline and install scuppers, that way any water that gets in will be evacuated out of the scuppers while underway.
 
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