flotation foam needed for dura craft boat

I ordered some of that Dow-Corning blue foam from my lumberyard. 4x8 sheets, 2" thick. It's stout, high density stuff.

Not all foam is created equal, and some of it isn't suitable for what you want to do with it. Somebody will weigh in with some ideas.

 

found this on the net http://www.jgreer.com/Foam Page.htm havn't got anything from them yet, but they seam to cost the least, I'm in the middle of a big time remodel of my boat and thinking ill need about 10 cubic feet of the stuff, kinda hopen some one else mite know of some were cuz the stuff is not cheep

 

Definately use the closed cell floatation foam. Anything else is insulating foam.

 

Find a supplier of concrete pouring/finishing supplies and such. I buy the 2" pink DOW closed cell foam for about $20. / sheet. (4 X 8) It's used for concrete slab insolation.
simmons18

 

MAKE SURE the Pink Foam WILLNOT get any gas on it, as it MELTS!!!! I tried it with a peice of the Pink Dow Foam, and it turned a 4" peice of foam to a pool of GOO in about 1 second!!! NO B.S. !!!!! oooh: I am still planning on useing it, but I will be sealing it in plastic sheeting to protect it.

I would LOVE to use the Liquid foam, but it would fill the runners from the front to the back of the boat where the splashed in water runs to the rear for the bilge pump to pump out! Also if you ever got a hole in the bottom of the boat it would be a REAL PAIN to dig all of it out so you could weld the hole shut! My 85 Bass Tracker had some foam sheets under the floor and sidewalls that filled the areas nicely and wern't attached, but they were watterlogged and disgusting from the split the previous owner had gotten in the bottom of the hull! So they were garbage! It looked to me that they were made from the liquid foam and cut into sheets by Tracker! I will try to get a hold of Tracker to see if I can buy the correct foam sheets to replace the original ones. I will also post here what I find out so Ya'll will know!

Hope this helps!!
Drew

 

You can make simple release molds for pourable foam.

 

I will never own an aluminum boat that has the expanding foam used between the hull and floor. I know a guy that had to scrap his Alumaweld(Xpress) because the foam had absorbed so much water he was in the process of having it removed and a new floor put in. Once the shop opened it up and removed the floor, it revealed many holes in the floor from what looked to be a chemical reaction with the foam and water. You could literally push your finger through the hull of the boat. The boat was about 8 years old, but it looked great everywhere but the bottom hull.

 

see if you find someone in the area with a foam packaging machine. we have one and it will make bags of foam 16" wide by however long you want.this would keep the foam wrapped in plastic and it would mold itself to whatever is laying against when it expands.

 

See if you find someone in the area with a foam packaging machine. we have one and it will make bags of foam 16" wide by however long you want.this would keep the foam wrapped in plastic and it would mold itself to whatever is laying against when it expands. but it won't stick to it. You would have to take your boat to them though.
This seems to be what they did in the bottom of my sea nymph.

 

Dale...You got any more info about this? Like what type of foam specifically? That sounds terrible, but pourable foam is used in boats all the time. I think if it were all a risk like this, there would be all kinds of warnings about it. Closed cell foam will not become saturated with water, so it kinda makes me think that this foam was not approved for marine applications.

 

Sounds more like damage from electrolosis.
Foam sheets aren't flotation foam. It doesn't have the density that flotation foam has. Its insulation. Big difference.

Many a jon boat has been foamed under the seats without the bottom rotting out.
Improper grounding, skinned wires, No zincs, and bad dock wiring will eat an aluminum boat up in a hurry.
I've seen people use the aluminum hull as a ground. Thats bad JU JU.
Alot of care has to be taken with aluminum when it comes to wiring.

 

If you were closer, you could get it 2 1/2" x 5' x 9' sheets from an auction I go to, factory seconds closed cell foam, used to pack missiles. I get it for 5 dollars a sheet. Darn stuff is unreal, I use it for my jugs, I have some calves using it for flooring and their house. I wired sheets together for there house as I got those darn calves, 8 weeks old, and it was zero. They love sleeping on it covered with straw. The only bad thing I have found with it is a magic marker does not want to write on it. It has a super slick finish, It will bend and you cannot break it. Great stuff. Water/gas/anything but fire won't phase it.

Another thing it will expand and contract with temperature changes. A friend of mine stuffed it between rafters in the summer and it the winter it wanted to fall out. lol It shrunk some. lol

 

Polyurethane is what they use for flotation, sometimes incorrectly called urethane. I've used this product. Good reading anyway. Only other advise is USE GLOVES! It's like getting super glue all over your hands.
http://www.shopmaninc.com/foam.html

But I'm still not sure you can't just a few cans of Great Stuff from Lowes.

Good luck with your project!

 

Depends entirely if you are insulating your boat or putting flotation in your boat.
Great stuff is insulating foam. Its also not closed cell. Its like a sponge.
Just any ol foam is not flotation foam.
Trust me. Boats are not something new or is building or restoring them.
Every conceivable way to cut a corner has been tried throughout the years and the vast majority of those cutting corners met with failure or disaster.

We see this all the time in stitch and glue boats particularly in the fillets.
People dont want to spend the money for epoxy and filler so they cut a corner with trying to make fillets with construction adhesive.
It dont work. They've just wasted the entire cost of the hull materials over a couple a hundred bucks.

There have been attempts at building boats using insulating foam sheets instead of using the marine foam sheets designed for building boats with.
It dont work. Its been tried.

The list of failures is long and extensive with loss of real property included.

If the goal is to float the boat dont use anything not labeled as such.
Its that simple.

There are other options. Its hard to beat good ol air for flotation. Sealed airtight compartments will float a boat as well or better then foam will.

Although I wouldnt do it because its just not my style, some people use plastic drink bottles with the tops screwed on to partially fill a compartment and then foam in and around them.
I've not done any testing but the weak point would be in the plastic cap. At some point its going to degrade. Quicker then the bottle itself will.

The whole idea of flotation foam is to float some portion of the boat or the entire boat in an upright attitude.

If my life or anyone else's life is dependent on the foam job I'm putting in there isnt but one way to do it.
The right way, with the right materials. If its expensive, well its just expensive. I'll save my pennies even if it means I may not be able to complete the project for another 6 months or year.

The last thing I want say is that the foam may be critical to the hull.
In other words the foam may be relied on structurally as a stiffener or support. You dont want insulating foam or foam sheets for this job.
An example of a boat that does this is the Carolina Skiff.
Many other boats use foam for sole (floor) support as its lighter then framing.

Once you need that foam job thats not there for you, its too late. Sink or swim.

 

The cheapest place I have found, by far. They ship UPS daily. Hope the moderstors don`t have a problem with me putting their # on. The only thing I would add is be sure to mix EXACTLY 50/50. And order twice as much as you think you need. Good luck

FIBERGLASS COATINGS
800-272-7890

 

These guys make the stuff.

http://greatstuff.dow.com/greatstuff/cons/faq.htm

How are latex products different from GREAT STUFF?

There are two key differences between latex foam and GREAT STUFF, which is a polyurethane foam:

1. Latex foams are typically “open celled” and, as a result, can take on water. In fact, the same properties that allow you to wash latex foam off your hands with water also mean that the cured foam can absorb water. This can cause wood rot or deterioration in areas where wet latex foam is next to wood, such as a window frame. In contrast, GREAT STUFF is closed-cell foam. It forms a water-resistant outer coating when cured.
2. Latex foam does not expand. GREAT STUFF expands to thoroughly fill all voids and cavities making it an ideal air-sealant.

 

The floor of that boat was welded and the foam was applied between the hull and floor, it was a factory floor. Closed cell foam will absorb water if there is any compression to it what so ever. If the aluminum flooring lays in direct contact with any closed cell foam, it's only a matter of time before it acts as a sponge. Some boat manufacturers use closed cell by making a mold and using this under decks where there isn't a compression problem.

It very well could have been a type of electrolysis because the foam held water and could not drain from bow to stern.

Both Sea Ark and War Eagle use a different type of foam sheets under their floors and not closed cell unless they have changed very recently. I know Xpress is still using closed cell which isn't a good idea. Go-Devil quit using closed cell because of water absorption.

 

Granted it's not labeled for flotation. But the link I had in the first post was to the real flotation foam. I've never used Great Stuff for repairs. I just didn't see the difference in the product formula. Still don't. Just because it's used as insulation doesn't mean it's not closed cell. I'm with you using the product that's designed for it.