Re: Hard pontoons for Zodiac
If you want to consider a somewhat zaney alternate, there is the two part urethane foam which is used for floatation in the cavities of many/most boats. It is defined as closed cell so it is not suppose to absorb water. I used it when replacing the stringers and deck in an old Reinell cabin cruiser. The stuff is kind of messy to work with but it expands 30 times in volume when used at 75 degrees F. Fiberglass Supply (
www.fiberglasssupply.com ) in Burlington, WA was where I bought my chems. The 2 pound density stuff is remarkably strong and it is POWERFUL!! You would want to very carefully calculate the volumes of each chamber before mixixng and filling. You only get 45 seconds after mixixng before the stuff takes off and it does just that!! I reccomend wearing old throw away clothes and having a fresh box of latex gloves sitting next to your full roll of paper towels. There is a commercial alternative. Local boat builders should have an automatic mixixng machine and could use their equipment to inject it down into the tubes. Some spray on insulation contractors use very similar equipment. You will end up with the same old tubes but they will never leak air again. Contrary to the stated claims, it can absorb water over time and you will need to maintain the tube fabric to avoid intrusion.
