Foam Floatation or Not?

[mcattac]

I am rebuilding my 18' Starcraft aluminum boat.
After ripping off the old rotted flooring I noticed that all of the Styrofoam sheets that Starcraft used under the flooring were saturated with water.
No doubt the water soaked floatation under the flooring contributed heavily to the rotting of the floor. Besides, I am positive the Styrofoam wouldn't float anyway it was so water-logged!

My question is whether or not to replace it?

I replace it and the same darn thing happens.
It gets wet and water-logged over time and serves no purpose except to rot my new flooring from the underside. And then doesn't keep the boat afloat anyway.

Or.......leave it out so the bilge stays relatively dry.

Just a side note - my boat really never stays overnight at a dock. Not that it never will, just that I prefer to haul it out each night. Also, I have two (2) bilge pumps, one that is 1-2" higher than the other. And I have two (2) batteries tied to them.

I know the law says that commercial boat builders must install floatation on boats smaller than 22', but does that also pertain to the private individual building/rebuilding his or her own boat?

I'm torn here.

What's the sense installing floatation that will only soak up water and become useless anyway? Especially if it will contribute to ratting of the flooring down the road?

Thoughts?

Mac

 

[sschefer]

Re: Foam Floatation or Not?

I'm doing my 91 MonArk 1800 (about the same as the Star Craft). Mine has poured in foam in the bilges and foam blocks everywhere they could put it above deck.

The way I see it is that the floatation needs to be there and removing it could put you at risk for at least Civil charges should your boat sink and an occupant was placed at risk because of it. I also doubt if an insurance company would pay off if they found that the floatation had been removed.

I don't know how far the Coast Guard would go to check your boat for proper floatation but I wouldn't want to have to worry about it either. There is an excellent thread about pouring foam that you should read. It's pretty easy to do.

As for the foam blocks, all mine were above deck. Before I put them back I'm wrapping them in shrink wrap but that's mainly to control the shedding. I hate working with that stuff. I may end up just pouring some new blocks and using them instead.

One of the things I've been also thinking of doing is putting down a layer of Tyvex moisture barrier between the wood and bilge and then venting the bilges with 3" non-perf Corex drain pipe. I think I can vent them up to the shelf brackets and leave it at that. Comming from a family of Contractors I know the importance of proper ventalation in the prevention of mold and dry rot.

You can watch my thread on the 1991 MonArk restore to see what I end up doing.

Steve

 

[mthieme]

Re: Foam Floatation or Not?

Plastic bottles are an alternative. 2 Liter soda bottles, laundry detergent bottles, etc.

I've always wondered about using Tyvek to wrap and seal the foam.

 

[mcattac]

Re: Foam Floatation or Not?

Plastic bottles are an alternative. 2 Liter soda bottles, laundry detergent bottles, etc.

Now this I like!
Great idea for sure!
Provides the flotation but not the water retention.
And the way my wife drinks diet Pepsi..........

Thanks!

Mac

 

[Mike Robinson]

Re: Foam Floatation or Not?

I'm no naval architech but I do know that the bilge is not the best place for floatation anyways. You put a bunch of water inside a boat and you get what's known as "free surface effect" (try carrying a pan of water to get the idea) and the boat capsizes.

sschefer has the right idea, get the floatation up higher and it'll help keep the boat upright if it floods.

Just my 2 cents worth

 

[sschefer]

Re: Foam Floatation or Not?

Agree 100% - I think putting foam in the bilge area is more of a structural effort. It adds deck support which in turn causes the combination of the two to act as bulkheads. The way I see it, the floatation is only going to do you any good if it is above the normal waterline.

I don't know for sure, (don't intend to test it), but I'm pretty sure that if I were to take all of the floatation that came out of my boat and tie it all to my Yamaha F150, 476lb, motor and then throw all that into 60' of water, I'd probably have to buy a new motor.

Steve

 

[Bondo]

Re: Foam Floatation or Not?

I know the law says that commercial boat builders must install floatation on boats smaller than 22', but does that also pertain to the private individual building/rebuilding his or her own boat?

Nope.... Only OEM...

 

[sschefer]

Re: Foam Floatation or Not?

So Bond-O what you're saying is that its pretty much like a Mattress Tag. The manufacturer is required by law to put it on but you can tear it off anytime you want.

I trust your knowledge of the subject and would like to learn more. Could you point me to information that you found that say's it's only a OEM requirement?

Thank you
Steve

 

[Bondo]

Re: Foam Floatation or Not?

Could you point me to information that you found that say's it's only a OEM requirement?

Ayuh,....

Type in Floation Foam into the iboats search engine....
It's a been a Well discussed subject....

 

[Flying Brian]

Re: Foam Floatation or Not?

Hy there. I am going threw the same dilemma on my boat project i have ben riping old wet foam out of my hull and rotten stringers thinking there is got to be a better way. From wat i have reading the new poly foam is more resistant to water then the old stuff so i ordered sum from US composites 2LB two part foam and made a block of it and put it in a trash can of water along with a chunk of old foam that was dry out of the boat after 24hr the new foam was steel dry and the old foam was soaked all the way threw.I was impressed after a lot of messing with the foam i think it will help make my boat more rigid and help absorb sum of the stress on the hull from heavy chop and help in deadening sum of the sound from the hull. that is my 2 cents Worth good luck with your project Brian

 

[mthieme]

Re: Foam Floatation or Not?

I don't know for sure, (don't intend to test it), but I'm pretty sure that if I were to take all of the floatation that came out of my boat and tie it all to my Yamaha F150, 476lb, motor and then throw all that into 60' of water, I'd probably have to buy a new motor.

Steve

Funny.
On my hydroplane I tie a crab float with 25' or so of line....just in case.
(My oldest brother flipped one once and the motor popped off.)

 

[oops!]

Re: Foam Floatation or Not?

bond-o is correct.....it is a munufacturers requirement.....

your boat is not a glass boat....its a tinny...the foam is not used for structure.

you do not have to put it back in.

it is possible there are insurance ramifications if it sinks.....but there is not much they can do about an older boat, so i guess that would be up to your insurance company.


this thread....

http://forums.iboats.com/showthread.php?t=233479&highlight=boat+rot+wet+foam+prevention

is a longer one....it is the most indepth discussion on foam in the forum....read it all for some good ideas

 

[marquette]

Re: Foam Floatation or Not?

i used swim noodles to replace all the above deck flotation and left the little bit of below deck foam out. i bought the noodles at Fleet Farm for .99 each. there are 43 of them stuffed in the boat.
if any body hits my boat and it breaks up it will look like a Rainbow Coalition Navy disaster with all the colors floating on the water.

 

[sschefer]

Re: Foam Floatation or Not?

Wow, that's a great idea. I have em for the grand kids when they come over to swim. They don't seem to break down in chlorinated water and sunlight so they probably wouldn't go all popcorn like the white styrofoam does.

 

[Tacklewasher]

Re: Foam Floatation or Not?

I am rebuilding my 18' Starcraft aluminum boat.
After ripping off the old rotted flooring I noticed that all of the Styrofoam sheets that Starcraft used under the flooring were saturated with water.

This does not sound original to me. Pretty sure they used some kind of pour-in or spray foam.

Sounds like the floor has been done once and sheet foam used.

 

[mcattac]

Re: Foam Floatation or Not?

This does not sound original to me. Pretty sure they used some kind of pour-in or spray foam.

Sounds like the floor has been done once and sheet foam used.

It was a more recent floor - and a crappola job on it too!!!!

But the sheets ARE from the factory.
They did this on the older ones.
Mine is a 73.

Thanks.

 

[bowman316]

Re: Foam Floatation or Not?

Funny.
On my hydroplane I tie a crab float with 25' or so of line....just in case.
(My oldest brother flipped one once and the motor popped off.)

What is a hydroplane?
You sank a gas motor and it still worked?