In all my years of boating, I never had too much to do with pontoon boats. There was one vacation several years ago on a lake in Virginia where we rented a pontoon boat. So, when a close friend of mine showed me a pontoon boat that he owned, I came up with the idea of getting it running. While my friend had not used the boat in five years, it appeared in good shape. I had just sold my 46ft. Bertram and was starting to miss getting out on the water. And, I knew my friend loved fishing but had been too busy to go out fishing for several years. The project would be fun and get us both out on the water while sharing some time working on the pontoon boat. It seemed like a win-win situation.
I researched and learned that the biggest risk on a pontoon boat was that the pontoons may have corroded and developed leaks. So, job one for us was to pressure test the pontoons. There were no visible signs of corrosion, but we were not taking any chances. We fitted a pressure gauge and valve to the back end of each pontoon so we could pressurize them. Both held pressure for 24 hours, so we were in good shape regarding leaks.
Next, we wanted to be sure the engine was in good shape before moving the boat. We rigged up a water connection to the base of the Nissan 50hp direct fuel injection engine outboard motor. We got it running with a borrowed battery and found it in good shape. Fortunately, before we tried to start it, we checked the onboard fuel tank for water, and it was loaded. To test the engine, we hooked it up to a separate fuel tank. It started after a few cranks and purred like a kitten.
We were ready to take the boat to the ramp for a test run. But first, since the trailer had not been used in five years, we decided to check the wheel bearings. The right-side bearing was heavily rusted, and the left-side was rusted. We discovered a cracked hub when we attempted to replace the bearing race. Once the bearings were repaired, we were ready to head for the boat ramp. Having been a member of the Coasties, I ensured the boat was ready for inspection just in case we were stopped by the USCG.
The following Saturday morning, we headed out to the boat ramp. We launched the boat without a hitch and then cruised for about an hour before bringing it to my Jackson Creek dock. Later that afternoon, I walked to the dock to check; everything looked fine. I started back up the dock, then stopped and returned; I better put the boat on my lift just to be sure. I eased the boat onto the lift, still floating but directly over the boat lift. I was looking forward to our first day out on the water and hopefully a little fishing for my friend and me.
The next morning, I came out to find the boat tilting to one side. I soon discovered that the port-side pontoon had sunk. I raised the boat up and observed a rotted section where the pontoons contacted the trailer bunkers. I let the pontoons drain for a day and filled the rotted parts with epoxy. Before I loaded the boat back onto the trailer, I checked out the bunkers and found a creamy accumulation in the areas where I had found the leak on the pontoons. A chemical reaction occurred between the carpet and the pontoon. I also learned that the rear pontoon compartment may be isolated from the forward compartments.
I don’t know yet what type of corrosion created the creamy substance and destroyed the pontoon. Some have suggested electrolysis, but the boat was not in the water. Some have suggested a galvanic reaction, but I am told that it requires dissimilar metals. I have seen a type of corrosion in a neighbor’s boat where he jammed his new aluminum fuel tank against treated lumber. Over two years, the chemicals in the treated lumber reacted damply against the aluminum tank, causing the formation of salt-like crystals and a massive hole in the fuel tank. However, the corrosion I found on the bunkers was not like salt crystals but more like whipped cream.
I researched the possibilities of repairing the pontoons and decided it was not a worthwhile project. However, I learned something about pontoon boats. First, they are lots of fun when they are in good shape. Second, testing the rear of a pontoon may not reveal leaks up front if the pontoon compartments are individually isolated. Third, I learned that the spongy carpet bunker covers on my trailer actually absorbed water and contributed to the corrosion that eventually caused the pontoons to leak.
It was a grand adventure and learning experience for my friend and me. As it stands now, we are planning to scrap the pontoons in the hope that the revenue from the scrap metal will help defray our costs. We have saved the motor and, perhaps, installed it on another pontoon boat sometime in the future.
My friend has decided to convert the trailer to a utility trailer once we have transported the old pontoon boat to the scrap metal yard. In retrospect, I think I might have attempted to repair the pontoons if there had been three on the boat. It just struck me that if the repair on one of the two pontoons had failed, it could be a catastrophe. It was not worth the risk, although I have great faith in some of the new epoxy. It is a shame because it really was a very nice pontoon boat.
My friend and I are down on this one, but we are not out yet. In the future, we may transfer all of the good parts of the old pontoon boat to another project boat we have been looking at. Who knows, maybe this time we will be successful.