I just read in the November BoatUS Magazine the survey report on the Legend 35/35.5. The author, Jack Hornor, says that the thin guage aluminum waste holding tank "...has a life expectancy of about 10 years maximum and should be replaced." I assume that my '93 Hunter 30T (and other similar Hunter boats) has the same sort of thin guage aluminum holding tank (it is aluminum, but I have no idea of the guage). Are other Hunter owners of boats of this type and vintage having problems with their holding tanks? Is Hornor correct? And if so, what sort of tank should the aluminum tank be replaced with?
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He's right...
In fact, optimistic. Urine is so corrosive that it will typically eat through a weld at a seam or a fitting within 2-5 years, and will eventually turn the bottom of the tank into a collander. The longest I've ever seen an aluminum tank last is about 10 years. Any that were any older than that weren't used to hold waste any earlier. Stainless is a bad choice too. It takes a little longer for urine to eat through the sheet metal, but it doesn't take significantly longer for a stainless tank to leak at a weld than an aluminum tank. Thick-walled (min. about 3/8") plastic is the best choice for waste holding...a good quality rotomolded tank will last for decades...as long as the boat lasts. Although your boat is a '93, unless you're the first owner, you have no real way of knowing how long the tank has actually been in use, or whether it's even still the original tank if it was replaced a couple of owners ago..and the first leak is likely to be very small. The time to replace the tank is when that happens. So pay attention...pressure test your tank at the end of every season. Easy way to do that: pump and rinse the tank VERY thoroughly...fill with clean water--put some food coloring in it if you want to. Block the tank vent, flush the head--dry or wet mode, doesn't matter--till you get enough resistance to know that the tank has become well pressurized...just don't OVERdo it. Go away overnight. The next day, inspect the area around the tank for moisture. No moisture, no leaks yet...you should be good for another season. So although Horner is right, it's not cause for any panic. It just means you need to pay attention. If that also means you'll have do some surgery to create access to be able to visually inspect the tank, so be it. You'll need access sooner or later anyway, not only to replace the tank, but also the sanitation hoses when they need it.
In fact, optimistic. Urine is so corrosive that it will typically eat through a weld at a seam or a fitting within 2-5 years, and will eventually turn the bottom of the tank into a collander. The longest I've ever seen an aluminum tank last is about 10 years. Any that were any older than that weren't used to hold waste any earlier. Stainless is a bad choice too. It takes a little longer for urine to eat through the sheet metal, but it doesn't take significantly longer for a stainless tank to leak at a weld than an aluminum tank. Thick-walled (min. about 3/8") plastic is the best choice for waste holding...a good quality rotomolded tank will last for decades...as long as the boat lasts. Although your boat is a '93, unless you're the first owner, you have no real way of knowing how long the tank has actually been in use, or whether it's even still the original tank if it was replaced a couple of owners ago..and the first leak is likely to be very small. The time to replace the tank is when that happens. So pay attention...pressure test your tank at the end of every season. Easy way to do that: pump and rinse the tank VERY thoroughly...fill with clean water--put some food coloring in it if you want to. Block the tank vent, flush the head--dry or wet mode, doesn't matter--till you get enough resistance to know that the tank has become well pressurized...just don't OVERdo it. Go away overnight. The next day, inspect the area around the tank for moisture. No moisture, no leaks yet...you should be good for another season. So although Horner is right, it's not cause for any panic. It just means you need to pay attention. If that also means you'll have do some surgery to create access to be able to visually inspect the tank, so be it. You'll need access sooner or later anyway, not only to replace the tank, but also the sanitation hoses when they need it.
Legend 35 Has All Plastic Tanks
To expand on the 35/35.5 review, probably because of his lack of space, the Legend 35 has all plastic tanks: fuel, water (65 gal in one tank), and holding.
To expand on the 35/35.5 review, probably because of his lack of space, the Legend 35 has all plastic tanks: fuel, water (65 gal in one tank), and holding.
IIRC, Hunter switched to plastic holding tanks
beginning in '91....I don't know how long it took 'em to change over the tanks in all models--I do know it didn't happen all at once...so it's possible that some models still had aluminum holding tank as late as '93, or even later.
beginning in '91....I don't know how long it took 'em to change over the tanks in all models--I do know it didn't happen all at once...so it's possible that some models still had aluminum holding tank as late as '93, or even later.
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