Queensland Australia is bringing in new laws beginning July 1st that all vessels must have sewage holding tanks. We have a 26 ft trailer sailer with an electric toilet and think we will install a flexible holding tank. Does anyone have any good/bad experience with these tanks or would we be better off with a rigid custom made tank? Space is a bit of a problem so flexible seems to be the easier option.
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Go Rigid
As difficult as it probably is to retrofit, and especially on a 26 footer, I think the consensus would be to go rigid. Unfortunately, haven't heard any positive comments about flexible.
As difficult as it probably is to retrofit, and especially on a 26 footer, I think the consensus would be to go rigid. Unfortunately, haven't heard any positive comments about flexible.
John is right...
Flexible tanks are not very satisfactory for sewage holding...it's almost impossible to prevent odor out the tank vent (because methane is flammable,all waste holding tanks MUST be vented to the outside of the boat)...they're highly prone to blow out a fitting at the first sign of clog...and it's very difficult to secure them to prevent chafe. The average life of a bladder tank is only about 15 years...compared to decades for a rigid plastic tank. You don't want metal either...urine is so corrosive that it typically eats through a weld within 2-5 years and will turn even 316 stainless into a collander within 10 years. Find a mfr who can make a custom polyethylene tank to fit your space. And before tackling this project, you might want to check out the link below.
Flexible tanks are not very satisfactory for sewage holding...it's almost impossible to prevent odor out the tank vent (because methane is flammable,all waste holding tanks MUST be vented to the outside of the boat)...they're highly prone to blow out a fitting at the first sign of clog...and it's very difficult to secure them to prevent chafe. The average life of a bladder tank is only about 15 years...compared to decades for a rigid plastic tank. You don't want metal either...urine is so corrosive that it typically eats through a weld within 2-5 years and will turn even 316 stainless into a collander within 10 years. Find a mfr who can make a custom polyethylene tank to fit your space. And before tackling this project, you might want to check out the link below.
Thanks....
...for your replies. I was told that the flexible tanks did not need a vent. So that's something I'll have to look into as well.
...for your replies. I was told that the flexible tanks did not need a vent. So that's something I'll have to look into as well.
The same flexible tanks are sold for mulple uses
And while it's not necessary to vent flexible diesel and water tanks, it is necessary to vent ALL waste tanks, including flexible tanks. Reason: diesel and water tanks leave the dock full...their contents are drawn out as needed, gradully collapsing the tank. Waste holding tanks, otoh, leave the dock empty and are gradually filled with organic material that generates gasses as it breaks down...and every flush brings in waste and flush water that displaces any air in the tank. So unless the tank is vented, the pressure created by incoming wastet and those gasses will blow out fittings and can even burst the tank.
And while it's not necessary to vent flexible diesel and water tanks, it is necessary to vent ALL waste tanks, including flexible tanks. Reason: diesel and water tanks leave the dock full...their contents are drawn out as needed, gradully collapsing the tank. Waste holding tanks, otoh, leave the dock empty and are gradually filled with organic material that generates gasses as it breaks down...and every flush brings in waste and flush water that displaces any air in the tank. So unless the tank is vented, the pressure created by incoming wastet and those gasses will blow out fittings and can even burst the tank.
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