replace foam or not?

[2MADAKAT]

I have just had the floor and stringers replaced on a 19' bayliner bowrider. My friend thinks<br />foam is a waste of time and always soaks up the<br />water making the boat heavier in the water, thus<br />slowing it down. He does not want to replace it but will if I insist. <br />Is it absolutely necessary?

 

[sundog]

Re: replace foam or not?

its a long running debate. in a perfect world the foam stays dry and in an emergency displaces water. in real world its going to get wet, eventually (weeks or years)and makes boat heavy, rots wood. its safer to have the foam, even wet (it still displaces water if boat is sinking, may slow the sinking). best compromise it a system of foam with channels drilled to central drain, so foam can air and drain.

 

[kd6nem]

Re: replace foam or not?

Foam usually strengthens the hull also. Newer types of foam are supposedly quite a bit more resistant to water absorbtion, so say some here. I have no first hand knowledge, but some of these guys on this board have really done some good homework on the subject. Use the search feature to find other threads with this info. Personally, I would go ahead and foam it.

 

[Solittle]

Re: replace foam or not?

All foam does is provide boyancy if you get flooded. There are other ways than foam to do that. Guys have posted that they use plastic jugs or whatever in place of foam.

 

[jmattor]

Re: replace foam or not?

Closed cell, polyurethane foam does alot more than provide bouyancy. It adds significant structural strength when used in conjunction with proper design and placement of stringers and ribs, not to mention insulation (both acoustic & thermal).<br />A proper mix of a two-part foam will create very uniform bubbles (thus-closed cell). If ripped or punctured the foam will only permit water to penetrate into those cells that have been pierced. The surrounding cells continue to do the job. The best designs incorporate chambers that are sealed and not open to air or light.<br />Use good quality, low density (not less than 2lb.). two-part foam. Be careful in your measurements so that you do not "over foam" and cause damage as it expands,and your boat will be the better for it.

 

[2MADAKAT]

Re: replace foam or not?

Thanks for the tips, I think I will have it done.<br />Is the two part foam something that can be added<br />after the fact?

 

[Chris1956]

Re: replace foam or not?

2Madakat, The foam should be added after the stringers and frames are glassed in and before the floor is installed. That way, if you pour in too much, it will simply expand above the stringers and may be trimmed to allow the floor to be installed. Some folks cut holes in the floor and pour the foam (in liguid form) in. If you know exactly how much is needed, this works. If you add too much the floor or stringers (even the hull) could be damaged.

 

[delta breeze]

Re: replace foam or not?

2Madakat,<br /> Knowing just how much foam to pour in a hull is a guessing game.Most "Pro's" Pour the foam in the hull after the floor is completed and before the floor is glassed.Pouring of the foam with the relief holes drilled properly,the foam will expand from the holes and can be trimmed and then glassed over the relief holes.I don't know how many people have poured the fom first and then tried to trim it,seems like alot more labor than needed to me?The foam doesn't cut very easy in bulk form.Good luck The Delta Breeze

 

[Boatist]

Re: replace foam or not?

In California for boat to be legal it must have floation. Full of water it must stay afloat.

 

[2MADAKAT]

Re: replace foam or not?

The floor is already in. Will not the sealed sectons under the floor provide some buoyancy provided the hull does not get punctured?<br />Freighters don't use foam. Thoughts?

 

[salty87]

Re: replace foam or not?

i've seen the answer to this one before....you can do whatever you want but there have been professionals and engineers doing it this way for a reason. manufacturers have to meet certain standards and one is for the hull to remain near the surface when fully submerged (boats under 21 feet or something). not being a manufacturer, you aren't held to the same standard. but, you'll be subject to the same laws of physics.<br /><br />your boat, your call.<br /><br />if you don't use floatation and re-sell, would you tell the potential buyer?<br /><br />edit: i guess it's your friend's boat and call

 

[quantumleap]

Re: replace foam or not?

If it didn't have foam in it when it was new, I wouldn't add it. Easy to keep the hull and bilge dry with no foam. Many production boats are built with no foam.

 

[Boatist]

Re: replace foam or not?

It is the law see below that it float. Not only that but it can save you and your Crew. It can save you from being sued should your boat sink and a friend die. If your boat was not legal I do not like your chances.<br /><br /> http://www.marathonmarine.com/Floatation.htm

 

[quantumleap]

Re: replace foam or not?

Boatist- So all of the boats being made today with no flotation foam are not up to code?? Don't think so.

 

[kd6nem]

Re: replace foam or not?

Maybe this applies to boats built after a certain point in time? I cannot imagine any retrofit requirement. (I do not dispute the wisdom of having flotation, just hard to imagine that half of us are unwittingly outlaws because we register, own, and use boats built before the requirement was established) Honestly, I do not know whether my boat has flotation. I stay to small lakes, and all passengers ALWAYS wear PFD whenever on board. Whenever I rip up my floor, no question, it will go back together with foam inside.

 

[Boatist]

Re: replace foam or not?

I have a 1967 14 foot alumimum boat and it has floatation. I have a 1980 21 foot aluminum boat and it has floatation. I found two places where USCG says must have floatation except for special racing craft, but also seem to say under 20 feet and less than 2 hp. Also says can not use enclosed compartments for floatation requirement. NMMA certification which replaced old BIA certification requires floatation, and for outboards requires level floatation.<br /><br />Lund Brochure says "injecting foam floatation into hull cavities allows us to exceed Coast Guard Regulations and along with the smooth riding IPS design, it helps to creat a quiter ride"<br /><br />What boat is sold with out Floatation?<br /><br />For me I know if I am in the ocean where water tempature is 53 degrees and the boat sinks then you have about 30 minutes of life left unless you can get your body out of the cold water in about 10 minutes. That enough for me to want a unsinkable boat for my family.