The use of foam as a flotation device?

[jurgenscraft]

I have my doubts regarding the use of flotation foam, I have seen how this type of flotation becomes waterlogged after time or was this just what the early type of foam did act, like a sponge, I am considering using 2 litre plastic bottles crammed into the various compartments through hatches cut into the deck. instead ,of the flotation foam , if the lids are sealed on tightly with something likea silicone sealer they should work pretty well,and last afairly long time,I just have my doubts regarding foam and how do you get that stuff out without removing the deck? if you need to for whatever reason.have any of you guys had bad experiences with flotation foam, Kind Regards William Wright

 

[sport15]

Re: The use of foam as a flotation device?

William,

The "water logging" effect will not occure in closed cell foam that is in good shape. Where trouble begins is when water gets between the foam and what covers it, freezes, separates the foam and begins to break down the cell walls. This will allow water to migrate around, freeze more and make bigger voids. My (new to me) '82 Whaler had a ding throught the gel coat into the mat about where the trailer fore foot roller beat it to death (some people show NOT be allowed to own boats). The previous owner thought the solution was to put bottom paint on the mat. When I dug out the foam I was AMAZED at how little migration there was.

Take a look at this link..
http://www.uscomposites.com/foam.html

The 2 lb foam kit is something I used in a skiff. I would not heasitate to use the stuff again and have been VERY happy with the results. Your plasitc bottle idea is good although I wonder if you would not end up with a lot of noise becasue of resonating rattling plastic bottles and if the bottles contact bildge water will the petrolium goop casue them to break down..
Another alternative is the closed cell construction foam. It can be put in place and removed rather easly.

Does it freeze much down your way?

Regards,
Dave

 

[Tail_Gunner]

Re: The use of foam as a flotation device?

8) Nice post, i had suspected freezing had something to do with the whole rotting process. However i think this has a greater effect on wood than the foam itself.

What would be intresting is to poll this forum on rot damage and see if there is any pattern as to whether it occur's at a much higher rate in the northern climates as to compared to the southern states.

As to the foam used in older boats and maybe still being used by mfg's i seriously doubt they were using a quality urethane closed cell foam............the accountant's who seem to run indrustry are just a bit to froogle for for that kind of foresight or customer satisfaction .........or Seperating there brand image from the rest of the pack..........Just a opinion.

 

[jurgenscraft]

Re: The use of foam as a flotation device?

William,

The "water logging" effect will not occure in closed cell foam that is in good shape. Where trouble begins is when water gets between the foam and what covers it, freezes, separates the foam and begins to break down the cell walls. This will allow water to migrate around, freeze more and make bigger voids. My (new to me) '82 Whaler had a ding throught the gel coat into the mat about where the trailer fore foot roller beat it to death (some people show NOT be allowed to own boats). The previous owner thought the solution was to put bottom paint on the mat. When I dug out the foam I was AMAZED at how little migration there was.

Take a look at this link..
http://www.uscomposites.com/foam.html

The 2 lb foam kit is something I used in a skiff. I would not heasitate to use the stuff again and have been VERY happy with the results. Your plasitc bottle idea is good although I wonder if you would not end up with a lot of noise becasue of resonating rattling plastic bottles and if the bottles contact bildge water will the petrolium goop casue them to break down..
Another alternative is the closed cell construction foam. It can be put in place and removed rather easly.

Does it freeze much down your way?

Regards,
Dave

 

[jurgenscraft]

Re: The use of foam as a flotation device?

Dave thanks for the interesting reply, I had a look at the link you supplied and find it very interesting,Dave we do not get the extremely cold weather here in SOUTH AFRICA, although there are times when we might go below freezing, but not for the period of time you guys have to endure, lakes and rivers do not freeze over like it does up north, the fuel tanks are above the deck and I have bilge pumps fitted below deck I wanted to fit some form of flotation as a added safety feature and I will look int what sort of foam is available boat builders are using a foam as flotation but we have other forms of flotation options, it has become law here in South Africa that all boats will have to be equiped with some form of flotation ,no matter what age or where the boat will be used, regards William Wright

 

[Bob_VT]

Re: The use of foam as a flotation device?

2 liter bottles are a great way to say money. Some people have actually added foam around them to keep them fixed and not moving.

 

[studlymandingo]

Re: The use of foam as a flotation device?

There have been some pretty lively discussions here regarding the use of 2 litre bottles as floatation. I personally think it is a great idea. I had a raft that my grandfather and I built for fishing made out of plastic milk jugs and a pallet. Worked great!

 

[Bondo]

Re: The use of foam as a flotation device?

Ayuh,........ I don't know if it can still be found in the archives or not,....
But,... I've been Screeming the Virtues of Plastic Soda pop Bottles ever since I got here.....

There's No need to use a Sealant on the Caps or Anything but the Bottles,+ their Caps, themselfs.........
If the bottles are Capped with their Own caps in a Cold environment, such as Just out of the Fridge, They'll hold a Positive Pressure for YEARS,....... All By Themselfs......

And,...... As long as the Sun doesn't shine on them,....... They'll Last ForEver.............
Sunlight is about the Only thing that Rots them.......And there Ain't much Sunlight in My Bilges........

 

[danpemby]

Re: The use of foam as a flotation device?

With the added benefit of keeping them out of Landfill

 

[jurgenscraft]

Re: The use of foam as a flotation device?

Well thats it then, plastic two liter bottles are what I am going to use, I have a lot of these bottles ( 200 plus) I will use them to add flotation as well as cleaning up the
enviorment, kind regards William Wright

 

[jurgenscraft]

Re: The use of foam as a flotation device?

Sorry I forgot to ask the following, how much lift ( flotation) from 200+ two liter cool drink ( soda) bottles? how do I know how much flotation a boat requires? I know the fully laden weight in kilograms how do I relate / equate, volume of flotation against weight of boat?to obtain a possatively bouyant boat ? confusing this lot is it not ? kind regards William Wright,

 

[Mr Hands]

Re: The use of foam as a flotation device?

I have my doubts regarding the use of flotation foam, I have seen how this type of flotation becomes waterlogged after time or was this just what the early type of foam did act, like a sponge, I am considering using 2 litre plastic bottles crammed into the various compartments through hatches cut into the deck. instead ,of the flotation foam , if the lids are sealed on tightly with something likea silicone sealer they should work pretty well,and last afairly long time,I just have my doubts regarding foam and how do you get that stuff out without removing the deck? if you need to for whatever reason.have any of you guys had bad experiences with flotation foam, Kind Regards William Wright

I actually used both.
I bought the US Composited foam, added every empty plastic container I had available, then pored the foam over it. 1 piece of advice: the bottles will float to the top of the foam so pour in a shallow layer of foam over the bottled first, then fill in the rest when the first batch sets up.

 

[Bondo]

Re: The use of foam as a flotation device?

1 Cubic foot, of Air,... will float about 63Lbs,...............
In Freshwater,.... Saltwater will be Considerably Higher........

You can do the conversions..................

 

[bassboy1]

Re: The use of foam as a flotation device?

Doesn't the Coast Guard require that there has to be foam in pleasure boats? I thought sealed air compartments can only be used in racing boats.

 

[AguaSki]

Re: The use of foam as a flotation device?

This is an interesting idea that I may consider. Does anyone have any ideas on what happens to the bottles if the boat is moved to a different elevation? When I drink a soda during a trip, I notice the empty bottles collapse as I drive from one elevation to another. My only concern with this idea is that repeated changes in elevation (pressure) could cause the bottles to expand and contract to the point that the plastic becomes weak and no longer holds air. This concern may not be well founded, but thoughts are appreciated.

 

[crunch]

Re: The use of foam as a flotation device?

opps........

 

[crunch]

Re: The use of foam as a flotation device?

This is an interesting idea that I may consider. Does anyone have any ideas on what happens to the bottles if the boat is moved to a different elevation? When I drink a soda during a trip, I notice the empty bottles collapse as I drive from one elevation to another. My only concern with this idea is that repeated changes in elevation (pressure) could cause the bottles to expand and contract to the point that the plastic becomes weak and no longer holds air. This concern may not be well founded, but thoughts are appreciated.

It's very well founded, if, as one poster suggested, you cool them first, they will develop a higher pressure when warmed, lower when cooled.

If you fill and cool them at sea level and then go up to higher elevations, and high temps, you might have a bomb under the deck.

This may also be why closed cell foam breaks down. (Combination of elevation and temp changes)


if it ain't broke, don't fix it.

 

[HookMaster]

Re: The use of foam as a flotation device?

Seems to me that the use of closed cell foam serves two purposes.........one for flotation and the other is structural value. Poured in between stringers, if done correctly, will add a ton of stiffening to the hull and if the floor is sealed properly water entry will not occur. It also adds a sound proofing effect as well. I am a firm believer in this product. Just finished using it recently....

 

[Bondo]

Re: The use of foam as a flotation device?

Doesn't the Coast Guard require that there has to be foam in pleasure boats? I thought sealed air compartments can only be used in racing boats.

Only if you're a Boat Manufacturer,...........
And,.... Even Then, All you're Required to end up with is Neutral Buoyancy..........
How you get there is up to You........

Once it's Your's,....As a Private Owner,.... You can Do as you Please........

 

[Purduebarry]

Re: The use of foam as a flotation device?

I think your nuts, soda bottles in a boat? Many here don't advocate foam at all. I'd leave it empty before I'd fill it with soda pop bottles. Wood floats, most old wood boats don't have foam. Floatation foam became a requirement with the popularity of fiberglass boats. The foam comes into play if you start to sink. The coast guard thinks this might keep you above water until help arrives. How many soda bottles can you hold and will they hold you up? Have plenty of PFD's on board and go with no foam!