Marine Head with "bag" Holding Tank

[thomm225]

Does this actually work for more than a outing?

I'm presently looking at a boat with this setup.

[toddster8]

Do you mean a bladder tank? I've had one for six years. Weekend use. You do want to empty it at every opportunity - don't store material in it for a long time - and rinse it with clean water. But I think that's true of every holding tank. The bladder is perhaps easier to empty completely than some rigid tanks.

Bonus: when it's collapsed and not in use, that locker can be used for storage. E.g. cruising gear that's not needed for day sailing, or even an extra potable water bladder to extend cruising range.

Bladders do need to be properly secured, supported, and protected from chafe.

[peghall]

Bladder holding tanks, like rigid tanks, come in a range of sizes--even up to 40 gallons. So you need to ask what size that one is. As for how long it should take to fill it up...multiply the number of people aboard by 3 gal/day/person. That's an average, not an absolute.

You also need to make sure it's a VENTED bladder, and that it's vented to the outside of the boat...'cuz that's what USACG regs require for all waste and fuel tanks.

If you were shopping for a tank I'd advise against bladders for a whole bunch of reasons. But this boat already has one, so if you buy it, we can address what to replace it with when that time comes. If the bladder is too small for your needs, there are a lot more shapes and sizes available than what you'll find the marine retail catalogs for a very reasonable price. I'll be glad to help you find one if/when you need one.

Todd, I hope yours is not an UNvented bladder.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

[JeffBurright]

We had one that came with our boat and cruised for 3 years with it. It worked fine, but you need to make sure the vent never gets clogged with waste or scale or the bag will start to inflate. You don't want that. We'd fill it with water and white vinegar every so often to clean it out and otherwise had no problems with it.

[thomm225]

Thanks for the replies!

I'll take a good look at it if I do decide to buy this boat.........which btw was mainly used for racing.

The anchor on this 12,000lb Pearson 10M doesn't look large enough to hold my present boat which is a Bristol 27

This may indicate that the boat was mainly raced locally and possible docked most of the time

[belizesailor]

Check around all the fittings for leaks. Its easy to make minor mistakes during installation of fittings on bladders which result in leaks. Leaks from holding tanks are...unpleasant.

[Sailmonkey]

Bags suck. The very compounds that make them flexible also make them extremely susceptible to permeation. If you were only day sailing and can pump out and flush the bag internals with fresh water after each cycle....it can work. But leave the soup in there for days or weeks....the boat will smell like a sewer.

[NSboatman]

Wot sailmonkey said. Bags suck.

I have removed more than a few from boats over the years, every one was saturated and permeated. And the boats never fully lost that horrible odour.

[JPA Cate]

thomm225,

It may not be analagous, but we had "too much" experience with bladders for drinking water. The first set failed from the aft glued seam (made before welding, and they were hypalon). The next 3 all failed very quickly, from one week to 3 weeks. These were bladder tanks with a 5 yr. guarantee. All failed at seams.

For that reason, I would be extremely leery of using a bladder tank for a holding tank. This is not to say that you might not do okay with one, but the effects of a sewage leak on board are just something I would have a hard time facing. Usually, such tanks have indoor/outdoor carpet between them and the hull to avoid chafe. Such material holding sewage seepage--mmmmmmh. No.

Ann