whild changing my hoses on my H336 alu hold tank this week, I noticed a hole in the pump out lower nozzle under the hose. I have the means to fabricate a replacement hold tank and nozzles out of 316 stainless steel. I think if I go with a plastic tank I will still need to install bulk head fittings which are also a joint issue where another leak could also happen. Has anyone used stainless for the hold tank?
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Not a good idea...
Stainless--even 316--waste tanks don't have a much longer lifespan than aluminum. The only recommended material for waste holding is polyethylene. You don't have to worry about leaking fittings...the female threaded "collars" are spindwelded into the tank walls...the male thread-barb fittings are self-sealing. They don't leak. And they don't corrode either.
Stainless--even 316--waste tanks don't have a much longer lifespan than aluminum. The only recommended material for waste holding is polyethylene. You don't have to worry about leaking fittings...the female threaded "collars" are spindwelded into the tank walls...the male thread-barb fittings are self-sealing. They don't leak. And they don't corrode either.
Peggy, if polyethylene so good, why do they use
S/S in some of the upper end boats like Hallberg R. You would think that polyethylene a less expensive and better product should be used instead. Any disadvantage of polyethylene?
S/S in some of the upper end boats like Hallberg R. You would think that polyethylene a less expensive and better product should be used instead. Any disadvantage of polyethylene?
A mistaken belief that SS is "bulletproof"
You'll mostly find SS waste tanks on European boats...because until recently there have been very few places outside the US where the use of holding tanks has been required. Builders mistakenly assume that if SS is superior to plastic and aluminum for any marine application, it must be superior for waste holding too. It's a case of, "if costs more, it has to be better." Because holding tanks don't get much use in Europe yet, they haven't been proven wrong yet...and if you try to convince 'em, they'll point to 20 yr old boats on which metal holding tanks are still in excellent condition. I used to have the same conversations in the late '80s with builders here...of course they're still in excellent condition, 'cuz while the tank may have been on the boat for 20 years, it's only been in use for a year. Today, there are still a few holdouts here in the US, but almost all builders have switched to plastic water and waste tanks...or included integral FG tanks into their hull designs, which IMO is an even worse idea than metal.
You'll mostly find SS waste tanks on European boats...because until recently there have been very few places outside the US where the use of holding tanks has been required. Builders mistakenly assume that if SS is superior to plastic and aluminum for any marine application, it must be superior for waste holding too. It's a case of, "if costs more, it has to be better." Because holding tanks don't get much use in Europe yet, they haven't been proven wrong yet...and if you try to convince 'em, they'll point to 20 yr old boats on which metal holding tanks are still in excellent condition. I used to have the same conversations in the late '80s with builders here...of course they're still in excellent condition, 'cuz while the tank may have been on the boat for 20 years, it's only been in use for a year. Today, there are still a few holdouts here in the US, but almost all builders have switched to plastic water and waste tanks...or included integral FG tanks into their hull designs, which IMO is an even worse idea than metal.
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