sdowney717
07-06-2009, 06:43 PM
http://www.jgreer.com/Foam%20Page.htm
This keeps coming to mind with me and my 37 foot egg harbor power boat.
Ok, my engines weigh 1050 pounds each and the gen set 500 lbs so
sp perhaps 2600 pounds dead weight. Would it be reasonable to consider using some of this foam at all? Would this "closed cell" foam ever soak up water?
[QUOTE]Q. How do I know how much foam I need to float my boat? I mean the wood is dry so it would float or be neutral.
A. Great question! Get your calculator ready, you will need it. A cubic foot of foam will float about 60 pounds of "dead weight". The wood parts of your boat will probably float, so you don't need flotation foam to offset that weight. The fiberglass parts of your boat will barely sink, so you really don't need much foam to offset the fiberglass- maybe one cubic foot of foam per two hundred pounds (or more) of fiberglass hull. The metal parts of your boat are what you really need to account for. A small (4-6hp) outboard may weigh 45-55 pounds. A 50hp outboard will weigh about 200 pounds.
So a 16 foot fiberglass skiff with a 50 horse outboard will need about six cubic feet of foam to keep it afloat. A 12 foot plastic kayak will only need one cubic foot. A 30 foot fiberglass sailing sloop with a diesel engine and lead keel would need about 150 cubic feet of foam. Actually, very few 30 foot keelboats have positive foam flotation, but it's not out of the question- especially when you consider all of the air pockets that would exist, as well as all of the wood interior components that provide some positive flotation./QUOTE]
This keeps coming to mind with me and my 37 foot egg harbor power boat.
Ok, my engines weigh 1050 pounds each and the gen set 500 lbs so
sp perhaps 2600 pounds dead weight. Would it be reasonable to consider using some of this foam at all? Would this "closed cell" foam ever soak up water?
[QUOTE]Q. How do I know how much foam I need to float my boat? I mean the wood is dry so it would float or be neutral.
A. Great question! Get your calculator ready, you will need it. A cubic foot of foam will float about 60 pounds of "dead weight". The wood parts of your boat will probably float, so you don't need flotation foam to offset that weight. The fiberglass parts of your boat will barely sink, so you really don't need much foam to offset the fiberglass- maybe one cubic foot of foam per two hundred pounds (or more) of fiberglass hull. The metal parts of your boat are what you really need to account for. A small (4-6hp) outboard may weigh 45-55 pounds. A 50hp outboard will weigh about 200 pounds.
So a 16 foot fiberglass skiff with a 50 horse outboard will need about six cubic feet of foam to keep it afloat. A 12 foot plastic kayak will only need one cubic foot. A 30 foot fiberglass sailing sloop with a diesel engine and lead keel would need about 150 cubic feet of foam. Actually, very few 30 foot keelboats have positive foam flotation, but it's not out of the question- especially when you consider all of the air pockets that would exist, as well as all of the wood interior components that provide some positive flotation./QUOTE]