Aluminum holding tank

[Dwayne Hillier]

Hi, I'm in the niddle of rebuilding my (new to me) sailboat. This boat has never had a head before, only a portable toilet. I've purchased a Jabco Manual Head and was going to fabricate my own holding tank. My questions: Is it okay to use aluminum for the holding tank? The holding tank is also only to have 2 openings, correct? One for pump out the other for...pump in, so to speak. Does it matter where these holes are in relation to one another, that is can I locate them based on the straigtest connection to the the head and pump out on deck? Do I need a vent and loop? Since I'm not putting an overboard discharge on the system this is not needed, correct? And finally is it okay to locate the thru hull for the water right next to the head, for eiser access when it is in use?

 

[T J Furstenau]

Holding Tank Answers

First of all, I would stay away from aluminum. If you search the forum, you'll find MANY posts about owners of boats replacing their aluminum tanks after they have rotted out. Urine is very corrosive to the aluminum and anecdotal evidence gives them 6-12 year life spans. Best to go with a plastic/poly tank. Ronco is where I got mine and it should last for as long as the boat.Secondly, regarding openings, you need at least three - in, out, and VENT. Vent is critical, in and out won't work without it, and oxygen to the tank is needed to keep the smell down.Third, hole location - recommend placing holes on top, as close to centerline as possible. This will prevent waste from backing into lines on each tack.Fourth, vent and loop - I'm not the expert on that, but assuming that you have one between the pump and the head, I don't believe that you need one anywhere else.Fifth, thru hull location. I don't see a problem with that.T J

 

[Peggie Hall/HeadMistress]

Aluuminum a bad choice

Urine is so corrosive that it typically eats through a weld within 2-5 years and turns ANY metal tank--even 316 SS--into a collander within about 10 years. Aluminum is ok for water holding but plastic is the only recommended material for waste holding. Check out Ronco Plastics http://www.ronco-plastics.com (no relation to the Vegomatic Ronco)...they make TOP quality water and waste tanks for a very reasonable price and have more than 400 shapes and sizes, over 100 of which are non-rectangular.Or, if your boat is <27', it would make more sense to stick with a self-contained system...a 5-6 gallon portapotty version that can be permanently installed and fitted for pumpout. All the advantages of a marine toilet and tank, but without any holes in the bottom, no moving parts to maintain, no plumbing except a pumpout line and vent...and holds at least as many flushes as 15 gal tank connected to a manual marine toilet. All holding tanks need 3 openings: inlet (at or on the top), outlet (at the bottom, or can be on the top with a pickup tube inside the tank), and vent (on the top...line MUST go to a vent throughhull outside the boat). Inlet and vent fittings should be inboard on the tank.No vented loop needed in the line from the toile to the tank, but one IS needed in the head intake. See the installation instructions for your toilet...they show that it goes between the pump and the bowl--to replace the short piece of hose the mfr uses to connect 'em--and should be at least 6-8" above waterline at any angle of heel.Yes, it's ok to put the intake thru-hull next to the toilet. In fact, that's the best place for it. Before you start this project, you might want to check out the link below...it includes step-by-step instructions for installing holding tank and should answer most of your questions.

 

[jimq26]

HMP has poly tanks in stock.

In fact, they can probably tell you exactly the tank configuration you need for your model.As Peggie said - you might be wiser to go with a Thetford 6 gal unit. We get 62 flushes between pumpouts with ours compared to about maybe 50 if you were lucky with the original (now thrown out) poly 15 gal. holding tank. Just securely mount it, connect up an air vent hose, and hook up a deck pumpout fitting and you're ready to "go".

 

[Dwayne Hillier]

I like your idea

...but I already bought the Jabco. I use HMP for almost everything I buy, including the Jabco I got...still in the box actually.