I’ve heard some rumblings about weak fuel tanks in the CHB 34. I’ve got a 1976 and was told by previous owner that he never filled it full due to tank worries and aging fuel. Are these fuel tanks that bad and is there any warning signs.
Thanks very much!
Worries are just that. You need to satisfy yourself on the evidence that you can see.
Old fuel? My tanks hold approximately 1100 litres each. at 100 hrs a year, 15l/hr, I have almost a 2 year supply. In low travel years, 3. I have owned this boat 27 years and haven't ever seen reason to worry about the age of my fuel. The bowl on the Racor filters will tell you the condition of your fuel. Mine stay clean between filter changes, which now, with the very clean fuel supplied (Low and Ultra Low Sulphur fuel get all other contaminants removed in the processes) are infrequent.
I would rather know how much fuel I have aboard, by filling to the top every time, than worry about low fuel levels allowing the pickup to draw from the dregs at the bottom of the tank, or running out far from a fuel supplier. You can choose which kind of worries to adopt.
CHB tanks are the same steel as other brands. Taiwan builders would all have had the same access to the steel that was available at the time. Some brands used aluminum, so have other issues with their tanks, sometimes far worse than for those of us with steel tanks.
Failure of the deck above will allow water to sit on the top of the tank, and when that has persisted for years, can rust through, introducing water into the fuel below, with the possibility of damage to the wet part of the bottom. Inspection of the top should be possible, though never easy. In my Taiwan built boat with steel tanks, there are hatches in the saloon floor above all of the tank fittings but for the one that is most important, but the space allowed is adequate for an inspection of all, including the deck fill. There you can see whether there is, or has ever been, failure of the deck above, and deal with it.
The second, and most unpredictable failure is of the welds fastening the panels together, which can rust from the inside or from the outside. The result will be the same, a pinhole leak.
The third, and least likely leak will be failure of the sheet metal itself. This can occur in aluminum tanks from contact with dis-similar metals, or in steel, from internal or external rust.
If you don't have a leak, and you don't have any evidence of failure of the deck above and can see enough of the body of the tank to be sure there are no trouble spots, you are not likely to need any immediate remediation. As pointed out above, properly built tanks should last as long as any other system on your boat.
