To foam or not to foam....

[cpriore]

Hello all, quick question. Im just about done restoring a 20' Novi hull. Fiberglass over wood, work boat. There is a bilge below the decks. I was wondering if i could remove that and fill the entire hull with foam. Is it worth it? Im not sure why they even have a bilge in there,the boat has freeing ports at the stern. I found a good price for some foam, i guess its 95 percent closed cell. so accidental water exposure shouldnt be a problem....Not sure, maybe someone here has done it with good results. thanks

chris

 

[sdunt]

Re: To foam or not to foam....

Its really a personal thing. I would suggest you search and read the old posts.

Personally I am NOT a pour in place foam fan.

 

[Robj]

Re: To foam or not to foam....

Hello there,

If the manufacturer put foam in there, I would replace it. However if there wasn't any foam in there originally, then I would not add any. The manufacturer did not feel it was required when the boat was built, so that is good enough for me. While foam does have some benefits, it can also be a liability if it gets wet.

Have a great day,

Rob.

 

[erikgreen]

Re: To foam or not to foam....

Note that there is a legal issue here. Boats under 20' that are homebuilt are required to have enough foam installed that they float when completely swamped by coast guard regs. I think to legally sell your boat if it's under 20 you need to have the foam installed if it was there originally from the mfgr.

I personally am not reinstalling foam in my 22' boat once removed.. I'd rather be able to inspect my underdeck spaces for water than trust that the foam is dry, and my biggest problem in the event of a sinking is going to be staying warm, not staying afloat.

Erik

 

[Bondo]

Re: To foam or not to foam....

Fill All the available space with Soda Pop Bottles......

They're Free,.....
They'll Last ForEver........
They Self-Drain..... No Water soaking,+ Rotting out your boat.......

 

[cpriore]

Re: To foam or not to foam....

I know it never had any foam so there shouldnt be any legal concerns. Ive heard the bottle thing somewhere else too. Thats a great idea. I wonder if id here them down there below my feet. That would suck to have to take them all out! The boat def wouldnt sink! Probably ripp out the floor.... Thanks for all the suggestions guys. I think im going with bottles. What the hell.

 

[Yacht Dr.]

Re: To foam or not to foam....

Leave it m8..I dont understand the whole pop bottle thingy. I still dont understand stuffing a bunch of bottles in the bilge will do anything..waste of time IMO.

Clean bilge is what I want..

YD.

 

[tmh]

Re: To foam or not to foam....

I put bottles in mine - just sealed it up this past weekend. A few tips i picked up on various sites and by doing it.

1.Open and screw closed the bottles on a cold day! That way, they won't be collapsing when it gets chilly out.

2. Have various sizes, mostly 2 liter. Fits in the tight spots.

3. Get some packaging foam to fill gaps on top to eliminate sliding around. NO WAY mine are moving, which was my biggest worry. They are in there tight. If the foam isn't sitting on the bottom it will not retain water.

4. Have a space a bottle won't quite fit?....open it, crush it into the spot base first, then seal it back up! This technique is how you jam them in tight.

I was very happy how my bottles worked out. They are more durable than you'd think and when fit in tightly they even provide a bit of floor stability! I assume they will also help in noise and vibration dampening, although I haven't been on the water with them yet.

Yacht Dr. soda bottles trap air and float, hense, the "pop bottle thingy", They also add a trapped air barrier for sound and vibration reduction (theory I read, anyhow). They have none of the negatives of poured in foam - water trapping. Now you can understand it, i hope.....still may not agree, but that's why many use this when replacing a floor.

My second choice would be to leave it empty.

 

[Tail_Gunner]

Re: To foam or not to foam....








http://www.nmma.org/government/environmental/?catid=642

forums.iboats.com/bbBoard.cgi?a=viewthread;fid=26;gtid=1247182;gpid=1248055#gpid1248055

 

[reelfishin]

Re: To foam or not to foam....

I sort of like the soda bottle idea, they won't rot, they won't soak up water, and their light.
I would venture to guess they may actually trap more air than pour in foam does, due to the larger volume capacity of each container. I could see using even spray can foam to secure them in place, if not any sticky, water resistant glue would work.

I just tore the floor up on an old aluminum v hull I have and it had some sort of pellet type foam floatation in it, I at first thought it was either white block foam or packing peanuts, but a closer look revealed tiny popcorn like balls. It's either an early style of packing or something that they came up with way back then. They were wet, but not soaked and heavy with water. They did end up everywhere once I exposed them on a windy day. It took forever to round them up and bag them. I'll be finding them around the yard for years.
The forward area did have cut block foam, like the stuff that they pack appliances in. It was cut to fit the bow area and then they decked over it. My old Grumman bass boat had that same type of floatation under each seat box and in all three corners.
I don't like any of the pour in foam floatation, it stops water from flowing out to the rear either to the drain or bilge pump. I wouldn't want anything in the way of clear drainage and would even consider doing anything that may promote some underfloor airflow to help keep things dry.

 

[Yacht Dr.]

Re: To foam or not to foam....

sorry..I still dont get the pop bottle thing..I mean..They wont help bouyancy..they wont help much deflecting your 350 CU motor screaming behind you..they wont do anything..oh..unless you slam into a rock and have a part of the hull that still has some bottles for you to hang onto until the Coasties show up ?

really..please..somebody explain why..really why pop bottles are better then nothing at all ? ( securing a tank with bottles wont cut it hehe ) .

YD.

 

[Zetman]

Re: To foam or not to foam....

I think I'm just going to use a bunch of pool noodles...Really!

 

[Tail_Gunner]

Re: To foam or not to foam....

In this forum water is the culprit rot is the enemy, Some of the guy's have been doing this for so long they become a bit opinionated as to foam, I guess there like reformed cigarette smoker's.......Neva Again...

It is good to see someone recommending a high density urethane foam, i put 8lb in a rebuild and was beggininh to feel like i had way over did it.... LOL who care's that hull is like a concrete block now..

 

[treedancer]

Re: To foam or not to foam....

Yacht Dr.

really..please..somebody explain why..really why pop bottles are better then nothing at all ? ( securing a tank with bottles wont cut it hehe ) .


I guess you could put a two liter under each arm and hope the coast Guard gets their quick.

 

[Bob_VT]

Re: To foam or not to foam....

The purpose is flotation.

Most boats have compartments and the bottles fill them up. If the boat has an accident and there is a crack or hole in the hull the floatation will keep it from going to the bottom.

Yo yacht dr. if it is an accident with a 350 and it hits hard enough the engine will seperate - this is floatation not crash protection.

For all the people who slept while in Physics ...... 1 Cubic Foot of air will support 60 lbs without any problem. Does anyone recall the television show Mythbusters when they recovered a sunked hull using ping pong balls?

Read the Coast Guard Rules posted in this forum. It's your choice.

Inflatable boats and pontoon boats use air pockets that does not mean they will sink because of lack of foam.

 

[studlymandingo]

Re: To foam or not to foam....

Fill All the available space with Soda Pop Bottles......

They're Free,.....
They'll Last ForEver........
They Self-Drain..... No Water soaking,+ Rotting out your boat.......

I think Bond-o just waits for the foam topics!!!!!​

 

[waternatureboy]

Re: To foam or not to foam....

I like the swim noodle idea over pop bottles, but the pop bottles will probably last longer. Those things are indestructable! I once fooled around with some by putting an air check valve (tire valve) in some caps, and pressurized them with an air compressor to about 125 psi. I then beat them with a hammer - even hit them pretty hard with the claw end of a straight claw hammer and they didn't pop.

Anyhow, they would keep your boat afloat if it filled up with water, unless your boat had a loose hatch in the floor where they could float out as the boat sunk. For those who don't understand - the bottles or noodles will float. If they are inside the boat where they won't come out, they will provide buoyancy - about 4 lbs. for a two liter bottle. That means that if you had 1000 of these bottles inside the boat (and they couldn't get out, even if the boat was full of water) and the boat with motor weighed less than 4000 lbs. (4 lbs x 1000), then the boat would not sink completely underwater.

Hope this helps someone!

 

[Nova II 260]

Re: To foam or not to foam....

If you should get a hull puncture and perhaps even puncture one bottle, you still have the rest that are not punctured. With foam you would eventually fill up the whole hull with water. I like the the idea of having many non-rotting non-moldy airtight compartments under the deck. At least you can drain it out. Foam traps water..forever!
The way I read the USCG regs Soda Bottle flotation works fine.
ANY floatation is only mandatory for "manufactured" boats of 20' or less. " ..... airtight chambers must not be integral to the hull...."
USCG Reg. Subpart F Para 183.112 (b) There ya are.

My health is ruined because of mold in my lungs. (houses and boats) I am adament about not giving mold & rot a place to grow and flourish! NO FOAM in my boat! A serious breach or swamping will ruin your boat, with or without floatation.

 

[Randyme]

Re: To foam or not to foam....

Guess it depends if you want to pay to have your boat pulled up from the bottom or just towed in to the dock...Hell yeah foam!