Fuel Tank Replacement
by Thom Reeves and Doug Smith
After we had a wonderful time at the National Regatta in Newport the last weekend in August, we and 4 other Catalina 36s traveled to Block Island on Monday morning. After tying up at Block Island Boat Basin we started getting ready for a 6 pm cocktail party. It was impressive seeing those 5 Catalina 36s neatly in a row, almost like at the regatta in Newport. As Doug and I got ready for the cocktail party Doug remarked that he smelled diesel fuel when he opened up the cabinet door under the galley sink. This was not really new to us because we have had a previous incident with a leaking Racor fuel filter.
We looked into the bilge and saw about a 1/2 inch of fuel floating on the top of the bilge water. We started investigating, looking first at the Racor fuel filter and the fuel pump. They were bone dry. Next we opened up the cover to the fuel tank area and all the connections were also dry. Then we took off the engine cover and inspected all the fuel lines. They, too, were dry. We remembered that we had just refueled in Newport that morning and maybe there was a leak in the filler tube. We checked it all the way up to the deck. Dry! Next we suspected that maybe the breather tube had come disconnected from the air vent on the stern. We didn’t see any leaking fuel when we filled that morning. Also negative. We were running out of ideas.
We called Don Flintzer (My Option) over for some help. He inspected all the same places we had done. Next we took a closer look around the bottom of the fuel tank on the starboard side at the bottom we found fuel between the tank and the floorboard that it sits on. My God, we probably have a leak in the tank. With Don’s help we removed almost all of the diesel fuel from the bilge water and stored it in a couple of plastic half gallon containers for later disposal and went on to the cocktail party.
In the morning we reinspected the bilge and found another 1/4 inch of diesel fuel. We had planned to leave the next day for Stonington but the weather was going to be a bit rough. Though two of the boats had to leave to get home, three of us stayed. Doug and I stayed mainly because we were afraid that if the leak were a crack in a seam, it could split wider open under pounding seas and we could lose all our fuel. We heard of a mechanic on the island named Tony Edwards and called him for help. He was able to stop by in the middle of the afternoon. He, too, checked all the places we did hoping for an easy solution. When we showed him the fuel between the tank and the base he said it had to be the tank. It was too late in the day to pump the tank out and remove it to inspect it. He would be by first thing the next morning.
Tony arrived with a man who had a fuel recovery pump and tank. In minutes the tank was empty. We noticed as he started to empty the tank through the sender opening that the fuel looked clean and the bottom was also mostly clean, thanks to a good regimen of Stor-N-Start and Biobor to keep the nasties from growing in the tank. Then before we could remove the tank, we unscrewed the four screws holding the water heater and slid it forward out of the way. The two screws in the rear were a bit difficult to get at without taking the galley cabinet faceplate off. Then Tony used a sawzall to remove a corner of the flooring under the water heater that covered the flange of the fuel tank. As he removed the hoses from the tank he saw that the hose that feeds the fuel pump had a screen filter on the end, which was at least half clogged with black gunk, even though the fuel was remarkably clean. He recommended that the screen be removed. The Racor filter would do a much better job of cleaning the fuel and be easier to clean and replace.
Then we removed the tank and took it up to the dock to inspect it. We saw several places where corrosion had set in near the edge of the starboard side of the tank. It seemed to be located in a couple of spots, none of which were along any of the welded seams. We looked at the plywood flooring where the tank sat and found rusty steel nails that directly corresponded to the corroded spots on the tank. Galvanic action? In any event the two metals should never touch each other, especially where there can be salt water. As we looked more closely at the corroded spots we found one hole that was leaking fuel.
Because of the corrosion, Tony was not sure that he could safely weld all the spots. He asked us if we could get a new tank. We called Catalina Yachts and since Gerry Douglas was on vacation we talked to Frank Butler. After a brief discussion of the problem Frank told us he would ship us a new tank immediately and we should have it the next morning. He gave us a good deal on the price of the tank. Tony was surprised at how little it cost us.
Doug and I cleaned the bilge and the entire Fiberglas flooring under the galley in preparation for the new tank. We scrubbed the floor for the tank and Tony came by later in the afternoon and put a heavy coat of epoxy paint on it to help seal the steel nails. The tank arrived the next day as promised. It came complete with new fitting and a new sender. This time the feeder hose didn’t have a filter screen on it. Tony also recommended that he remove all the Teflon tape that held the fittings because the diesel fuel does something to the Teflon tape. He replaced it with plumbers pipe dope. He then laid down three double thickness strips of self stick black rubber called “Grace Water and Ice Shield” to cushion the tank and separate the aluminum from the flooring. This meant that the wood brace at the top of the starboard side of the tank had to be shaved to allow for the extra elevation of the tank. He also put a single thickness of rubber on the wood above where the tank wedges in on the starboard side.
We repositioned the water heater. Again the aft two screws were difficult to get at. Tony reconnected all the fittings and we filled the tank, bled the engine for a few minutes and ran it for a half hour without difficulty. Happy ending!
Thank you, Tony Edwards, of Edwards Marine, Block Island, Rhode Island. And also a special thanks to Frank Butler for dealing with our crisis so promptly.
Thom Reeves and Doug Smith
Carter-Creagh, 907
Fuel Tank Replacement (1)
Fuel Tank Replacement (2)
Fuel Tank Dimensions