foaming question

[justride]

I did a search, but don't have time to read everything to find it.

How much 2 part foam do I need to order to refoam a RN.
I have all the foam out of the back,
Thank's...

 

[douglee25]

4 cu. ft of foam should cover you.

Doug

 

[sjetrider]

1 gal. total 1/2 ga of ea. part.

 

[justride]

from uscomposites.com will the 4lbs kit work or do I need the 16lbs kit.
Thank's for the help.

 

[douglee25]

from uscomposites.com will the 4lbs kit work or do I need the 16lbs kit.
Thank's for the help.

Based off of their 4lb. density chart, you will probably need the 16lb kit.

Doug



4 LB Density Urethane Foam
Common Applications: This 4LB density foam is suited well for most flotation applications that require more support than the 2LB offers. This foam is recommended to be used when supporting gas tanks and some deck areas. Choose this density if you feel that the foam will be required to withstand minor to moderate loads. The 4LB density also works well in floating decoy or taxidermy applications as well as many other sculpting, casting, carving and other filling applications. More questions? [Try our Foam FAQ.]

Cat No. Kit Size Approx. Coverage Price
FOAM-0404 4 LB Kit 1 Cubic Foot $18.50
FOAM-0416 16 LB Kit 4 Cubic Feet $54.00
FOAM-0480 80 LB Kit 20 Cubic Feet $215.00
5 or more kits of the FOAM-0480 $205.00 / Kit
Product Information:
Free Rise Density: 4.0 lbs cubic ft.
Expansion Rate: Approx. 15x Liquid Volume
Buoyancy (flotation): 58 LBs per Cubic Ft.
*Physical Properties:
Parallel Compressive Strength: 90 psi
Tensile Strength: 110 psi
Shear Strength: 70 psi
Flexural Strength: 120 psi

 

[Crab]

4 lb foam is really strong. anything denser is going to set like concrete.

 

[beachedflunkey]

Did you do a full or partial refoam? I just refoamed about a third of my ski the other night with a 16lb kit of 3lb foam and only used maybe 20oz of each. So I should have 2/3 of the kit left over if you are interested.

 

[justride]

I did a full defoam in the back, So I need to refoam it all.
Will what you have work,
if so we can work something out.

 

[beachedflunkey]

Sounds like you need a full kit for a full refoam :dunno:

 

[Shonuff]

2 pound, 3 pound, or 4 pound will be fine.

Do not get 16 pound.

4 cubic feet in plenty.

 

[justride]

2 pound, 3 pound, or 4 pound will be fine.

Do not get 16 pound.

4 cubic feet in plenty.

so 2 4lbs kits will work,

 

[douglee25]

2 pound, 3 pound, or 4 pound will be fine.

Do not get 16 pound.

4 cubic feet in plenty.

You're getting density and cubic feet mixed up. It's 2 lb density, 3 lb density, or 4 lb density that rang in sizes from 1, 4, or 20 cubic feet. If you want 4 cu. ft, you need the 16 lb kit.

Doug

 

[justride]

what's the stuff that blowsion sell's?
I would like to spend my money with people that support your sport!!!

 

[yamaslut]

I used Hi-Bond 2lb Density foam to refoam my tray area....
It took a half gallon, maybe a tad more, but I had a bit
more waste than I wanted... It's light as hell...



so, it takes 4 cubic feet to do the whole tray?????

 

[beachedflunkey]

If it takes 4cu ft and the buoyancy is 60lbs/cu ft, where does the other 80 or whatever pounds of buoyancy come from to float an sj?? Does the nose foam help that much? Aftermarket poles don't have foam - not sure about a/m hoods.

Am I doing correct math according to uscomposites' info?
4cu ft = 8lbs of 2lb foam = 12 lbs of 3lb foam
4cu ft of 2lb = 240lbs of flotation
4cu ft of 3lb = 236lbs of flotation

 

[douglee25]

I used Hi-Bond 2lb Density foam to refoam my tray area....
It took a half gallon, maybe a tad more, but I had a bit
more waste than I wanted... It's light as hell...



so, it takes 4 cubic feet to do the whole tray?????

Between 3 - 4 cubic feet for the gunwhales and tray I believe.

Doug

 

[chrisdoc0608]

hate to thread jack, but im abt to do this also, if i have some water penetration ( leaking out of exhaust exit on sj) is it necessary to completely refoam? it floats well and dosent lean to one side or the other, i was thinking abt just doing the gunwhales. would that be enough as long as i seal it well afterwards?

 

[RideItLikeYouStoleIt]

I am definatley sure you need the 4 cubic feet of foam to do teh entire tray. 100% so if your using 4lb foam then you need the 16lb kit. Whoever said the thing about the buoyancy from the foam you should understand that the foam isnt making the ski buoyant. The fact that it is displacing water is whats making it buoyant. The volume that the ski displaces in water is what the ski weighs. The foam is in there incase you get a crank ro something and it fills with water the volume that the foam displaces in water is more than the ski weighs so it will still float.

4 cubic feet of water is 4 ft^3
Density of water is 1000kg/m^3

Unit conversion (4ft^3)* (.3096^3*m^3)/ft^3 = .1187 m^3

(.1187m^3)*(1000kg/m^3)= 118.7 kg

I think a kilogram is 2.2 pounds so 118.7*2.2= 261.1 lbs

The foam in the back can hold up 261.1 lbs so if you throw in some of the other things that are hollow or foamed like teh handle pole the ski will float if you sink it.

 

[ANT]

u dont need all that math just buy a 16lb kit of 4lb density foam. You get two gallons, one gallon of part a and one gallon of part b.

 

[RideItLikeYouStoleIt]

the math wasnt to explain 16 lb kit of foam.:biggthumpup: