Dingy conversion
- Thread starter dLj
- Start date
Yes, but then you end up with old Hypalon inside which is useless mass. At least the foam serves a purpose.
That is not what I was thinking. Use the inflated tubes to create a mold. You would have to put a releasing compound on the Hypalon and remove the original tube. Probably need to cut the mold down the center and then reassemble and pour in the foam. Now you have the right shape and don’t have to shape the foam with a sander. Now it is time to glass.
Seems like a lot of work for a slightly nicer dinc YBYC
The dingy I was on that had it done to, showed nothing of the concerns you mention above. As far as bouncing off motherships, it would be similar to a hard dingy. The dingy my friend had was a number of years old, had traveled a notable amount, had been used to dive from, and was in quite good condition.
I asked my friend at the time and all he could remember was it was done down south. I don't remember if it was in the islands or Central America.
The only questions in my mind are how was it done and is it worth the effort.
dj
I'd be worried about the weight of the final product and the cost. According to the ads, pourable foam has a density of about a kilo per cubic foot, and 10 cu ft costs $250 at Defender. I'm guessing for a typical 10 foot dinghy with 18 inch tubes that you would need 40+ cubic feet of stuff, or 40 kilos = 100 lbs. Of course that is the optimal inflation and assumes no compression so each cell inflates fully. That's like carrying another outboard motor in the dink, so performance would be reduced for planing, but not for harbor puttering. This would cost about $1,000.
Hi-Bond 2-Part Pour In Place Liquid Urethane Closed Cell Foam - Makes 10 cu ft
Hi-Bond 2-Part Pour In Place Liquid Urethane Closed Cell Foam - Makes 10 cu ft
- Applications: Fills Boat Hulls and Cavities for Flotation or Insulation
- Resistant to Gas and Oil, Cured Volume: 10 Cubic Feet Displacement
- Container: 2 Gallons - (1) Gallon Part A and (1) Gallon Part B, Mix Ratio 1/1
This weight question got my wheels turning....SO! ... I'm taking a dive down the rabbit hole. (How many metaphors can you cram into one introduction?)
I have used expanding foam over the years in a few of my boat restorations. For big volumes I would first stuff in bits and pieces of the pink foam board used for foundation insulation and then pour in the expanding stuff and “glue” it all into a solid chunk. But when thinking about floatation, what you really want is a very low-density material that will be structurally sound.
What if you first filled in the space with something like ping-pong balls and then poured in the expanding foam? I guess the first question to answer is will the ping-pong balls dissolve in the liquid foam solvent before it sets up. That would end that experiment. According to google tennis table balls are made from Acrylonitrile butadiene styrene. That would definitly dissolve in strong organic solvents ... I could not easily find the solvent used to carry the monomers for the polyurethane expanding foam... but old-school ping-pong balls were cellulose and you can still buy cellulose ping-pong balls.
If you are filling a BIG space, I think you could also use PVC ball pit balls... like the kind kids jump into for ball pits....but I would worry that the polyurethane foam would not stick to that as well. Maybe also worth a small scale experiment????
I’ve even imagined using small 12 oz PETE soda bottles as the gap filler. I know PETE is resistant to most solvents but the "stick" issue might still be a problem.
(It must be winter)
I have used expanding foam over the years in a few of my boat restorations. For big volumes I would first stuff in bits and pieces of the pink foam board used for foundation insulation and then pour in the expanding stuff and “glue” it all into a solid chunk. But when thinking about floatation, what you really want is a very low-density material that will be structurally sound.
What if you first filled in the space with something like ping-pong balls and then poured in the expanding foam? I guess the first question to answer is will the ping-pong balls dissolve in the liquid foam solvent before it sets up. That would end that experiment. According to google tennis table balls are made from Acrylonitrile butadiene styrene. That would definitly dissolve in strong organic solvents ... I could not easily find the solvent used to carry the monomers for the polyurethane expanding foam... but old-school ping-pong balls were cellulose and you can still buy cellulose ping-pong balls.
If you are filling a BIG space, I think you could also use PVC ball pit balls... like the kind kids jump into for ball pits....but I would worry that the polyurethane foam would not stick to that as well. Maybe also worth a small scale experiment????
I’ve even imagined using small 12 oz PETE soda bottles as the gap filler. I know PETE is resistant to most solvents but the "stick" issue might still be a problem.
I dunno, considering where this thread is going maybe dingy is more appropriate
On the other hand you can always hang the dingy up by its stern and cut the ends off the tubes as if they were pillow cases and stuff as many packing peanuts into them as you could. Then duct tape the tube back on and all done./ no $ just don't use suntan lotion on your neck while doing it.