A study by Underwriters Laboratories (UL) for the U.S. Coast Guard has shown that aluminum
tanks last an average of 10 years. Life spans are comparable for other metal tanks.
There is no data on the life of plastic (molded cross-linked polyethelyne, PE) tanks, but plastic has been used since the 1970s with no significant problems. They don’t corrode and they last almost forever. They have no seams or welds to leak.
You rarely see PE tanks over 100 gallons (380 litres) because they can’t be baffled.
PE tanks do permeate a very slight amount of vapour through the tank wall. If the amount is greater than that specified by the regulations
, the space containing the tank must be mechanically ventilated. But, if it is installed properly there is no danger
The problems that have occurred with PE tanks have been caused by people putting a hole in the tank, or by bad gaskets.
Fibreglass tanks have been used since the ’60s and work well with diesel
although there are problems when used for gasoline. Some manufacturers of luxury yachts, such as Hatteras, use fibreglass diesel
tanks and have not reported any significant problems.