Do I need foam in my hull??

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Do I need foam in my hull??

I've heard stories of people hitting partially sumberged RR ties, stumps, logs, and other debris. My thinking was that if something punched a hole in the hull, closed cell foam would prevent total flooding and allow me to motor back to shore. The flip side is that with ping pong balls or empty pop bottles, they would at least be able to tell where the boat went down.

Pour foam definately adds some time to a restoration project and it makes you want to cry to be putting those holes in your brand new deck. But for me, the safety aspect was more important. I spent a tremendous amount of time on boats that were designed to go underwater and come back up. My 18' runabout isn't one of those :D.

Of course, everyone is certainly entitled to their own opinion.

I agree 100%. If you are rebuilding your boat, put in new stringers and deck, if done right, (IE pressure treated ply or other rot proof materials) than a full foam job should not be a cause of concern about water absorption and rot.

Do it right, and make it safe. Also, its best to foam above the deck if possible, as per the USCG.
 

109jb

Lieutenant Commander
Joined
Jul 15, 2008
Messages
1,590
Re: Do I need foam in my hull??

Figuring out the flotation of anything is relatively easy. One cubic foot of water weighs 62 pounds. Now if you have a one cubic foot piece of foam that is 2 lb density it weighs 2 pounds. It can hold up 62-2=60 pounds after taking into account its own weight.

One thing to consider is that the pourable foam comes in many densities. The 2 lb foam is most commonly used, but the 4 lb is much more resistant to water absorbtion. I opted for the 4 lb pourable foam in my rebuild.

In my opinion, the foam isn't there to make it easier to retrieve if swamped. This is a nice side benefit, but the real reason for it is so that if it does get swamped, or capsizes, the occupants have something to hold on to. To me this iis most important if you boat in a smaller boat in "big" water. I take my 16' boat out on Lake Michigan occasionally and weather conditions can change in a hurry making swamping a possibility. If it happens to you and you are far enough from shore and help, you will be glad to have the boat still there even if half under water.

People will say that bbigger boats don't have foam so why put it in smaller boats. Well my opinion is that the bigger boats can handle much rougher water before getting to a dangerous poiint, and smaller boats are operated by begining boaters more often than larger boats. 2 good reasons in my opinion to have the foam.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
13,114
Re: Do I need foam in my hull??

When I was doing mine over I contacted 4-Winns and they said it was both structural and for flotation...so I replaced it....and found it easiest to just pour it befor the deck was installed and then cut it flush with the tops of the stringers...then install the deck...made a very solid boat...
 

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