Replace or Fix a leaky Fresh Water Tank

[Scuba-Do]

Hi, I have a 1985 Bertram 30 with 61 gallon fresh water holding tank. Recently the tank has developed a leak. I cannot see the leak, however I can see water trickling into the bilge every time I fill up the tank. Over time the majority of the water in the tank is emptying into the bilge. The tank is original and is galvanized steel. The water system is pressurized. Should I remove the tank and have it repaired or should I cut the tank out and go with a new tank. If you suggest the latter, then what type of tank should I get that would be compatible with my existing tank for my pressurized system? Also, if you have experienced this before, how do I detach the original tank from the water pump line. There is very little room between the tank and the bulk head for the engine room...where the water pump is located. What kind of fitting is that and how do I detach it so I can remove the original tank? Thanks [8D]

[IRGuy]

Ed... I have no ideal how a Bertram 30 is laid out, so I can't offer any assistance on the physical aspects of tank replacement, but I can offer some help in what seems to be the preferred material for tank replacement. There have been several discussions about water tank replacement in the Bertram 31 forum as well as here, with the final conclusions being pretty much as what I state below. As far as I know all Bertram water tanks were aluminum, and I don't recall hearing of galvanized steel, but the aluminum seems to fail after 25-30 years. The material of choice for replacement tanks is rotationally molded polyethylene. The best source for such tanks is Ronco Plastics. http://www.ronco-plastics.net/marinetanks.html I have not heard of anyone repairing an old aluminum tank with any success. Ronco sells direct over their web site, and if the truth be known they also make many of the tanks other marine outlets sell. Most people look at their unique application and select a tank from Ronco's catalog. They are very accomodating, and will mount fittings on the tank to your specifications, so before you contact them it would be a good idea to have a sketch you can fax or email to them so they can make comments and determine final pricing. You mention that your water system is pressurized.. I hope I am not sounding condescending, but the way you described your water system makes me feel I should to be sure you don't have any misconceptions. So to be sure let me say that all our fresh water systems are pressurized, but that tank itself is not part of the pressurized system. The tank is just a vented reservoir that is connected to a pump which draws water from the tank and pumps it into the delivery piping, so all the piping, etc, downstream of the pump is pressurized, while the tank and pump suction lines are at ambient pressure. As far as tank removal.. I believe most owners have had to cut their old tanks apart.. they weren't originally installed with removal 25 years later in mind. Then, in the end, you might find that you can't find a way to get a replacement tank of the same volume into the space the old tank occupied, and you might have to settle for a smaller tank that you can get through the openings and hatches that kept you from removing the old tank in one piece. Unfortunately all this is not easily accomplished, and there is no simple fix for a leaking tank.