Aluminum holding tank

[Bayou Sailor]

Hey guys, without getting into too much detail, Margarita is a 1969 Cal 34. The head was removed by a PO years ago and replaced with a porta potti. I want to install a new head with holding tank. Due to configuration, I'm trying to determine a holding tank solution. The easiest fix is to convert the 21gal aluminum freshwater tank under the v-berth into the head holding tank and install a new freshwater tank under the port settee. Bad idea??? Thanks for any help.

[S/V Illusion]

Not a good choice for a holding tank. It will survive for a while but will eventually erode from the inside.

[peghall]

Aluminum--in fact, ANY metal, even 316 SS--is a bad choice for sewage holding because urine is so corrosive that it'll eat through it, turning the tank into a colander. Plastic--rotomolded polyethalene is the most common--has been the recommended holding tank material since the early 90s.

Ronco Plastics Ronco Plastics marine Tanks is your best source for a tank. They make TOP quality thick-walled water and waste tanks for a very reasonable price and have more than 400 shapes and sizes, over 100 of which are non-rectangular, and they install fittings in the sizes and locations specified by the customer when they make the tank. There are retailers who sell Ronco tanks, but Ronco sells direct for a much lower price...and they're great to work with.

When looking at drawings it's important to know that there is no top or bottom until the fittings go in, and YOU decide where they go. So rotate, flip in any orientation to find the tank that fit your space.

The bow under the v-berth is an excellent location for a holding tank and Ronco has a couple of V shaped tanks, one of which should fit your space there.

21 gallons is not much water... Ronco also makes water tanks (same molds as holding tanks0 and often give a very discount for a 2 tank order. So see what they have in about a 40 gal tank that'll fit under a settee.

--Peggie

[Bayou Sailor]

That is great information. Thanks Peggie. I guess what they say about you is true. You really know your shi$ about toilets!!! Thanks!!

[peghall]

Dometic SaniPottie 975MSD Toilet @Defender| A 50 yr old boat is bound to need a lot of "boat bucks" in addition to a legal sanitation system. If you aren't hell bent on having a "real" marine toilet plus a remote holding tank and all the related plumbing, there's another solution that'll only cost you about $200: Another portapotty but this time an "MSD" version.

The "MSD" designation in the model name/number means it has fittings for a pumpout line and vent line, and is designed to be permanently installed (actually just sturdier brackets than portables, so you could still take it off the boat if you absolutely have to), which means that although it's still called a PORTApotty, you don't have to carry anything off the boat to empty it.

A 5-6 gallon model is household height and holds 50-60 flushes...you'd need at least a 30 gal tank to hold that many from a manual marine toilet and I'm not sure a "composter" can hold that much poop and organic material needed to absorb the liquid in solid waster (which, btw is about 75% water). No plumbing needed except a vent line and pumpout hose--so no new holes in the boat...and -0- maintenance needed except for rinsing out the tank--which you can do with a bucket while it's being pumped out. Total cost including the pumpout hose and vent line is about $200--a fraction of what you'd spend for toilet, tank and all the related plumbing needed.

Is it a permanent solution? No. But you wouldn't be the first owner of an older 30'+ boat who opted to this to give 'em a working toilet and holding tank for a fraction of the cost for a "real" system while they took care of everything else the boat needed.

Just an idea... If it appeals to you, check out the Dometic 975MSD, which Defender has for a very reasonable price Dometic SaniPottie 975MSD Toilet @Defender|


--Peggie

[Bayou Sailor]

Thanks Peg, but there is a space issue also. The majority of the necessary boat bucks have been spent. I saved the head for last. I've had the boat nearly a year and have accomplished a lot. The seacock for the head outlet is directly behind the toilet. So, there is about a 4" shelf that was built for the porta potty to fit on so that it wouldn't hit the seacock. it's pretty tall with the standard porta potty now. The larger size tanks would make the toilet too tall for everyone but amazon women.

[belizesailor]

Would a "composting" head work for you?

Eliminates the whole holding tank issue and can be a permanent solution.

[Bayou Sailor]

Thanks for the response belizesailor, but there is no room. I'm good with installing the tank and plumbing. I just didn't want to replace the aluminum tank if I didn't need to. Thanks!

[peghall]

It was just an idea...

Toilets: Assuming you want a manual toilet, the Raritan PH SuperFlush is the top rated manual toilet...a bit more expensive than other manual toilet, but, unlike other manual toilets, will provide at least 20 years of reliable trouble-free service with minimal repairs if it's just kept well lubricated, a new joker valve annually, and is rebuilt (kit about $60) every 5-6 years
Raritan PH SuperFlush Don't let the list price scare you...this retailer has it for a LOT less Boatersland Raritan PH SuperFlush

If you want the "push button convenience" of an electric macerating toilet, Raritan's SeaEra is also the top rated sea water macerating electric Raritan SeaEra Promo Sheet The same retailer has this one for the best price too Boatersland -Raritan SeaEra Electric Marine Toilet I strongly recommend that you upgrade the standard single flush button to Raritan's "momentary flush" that has 3 flush options: bring water into the bowl ahead of the flush, dry flush, and simultaneous water in/bowl contents out. Boatersland RaritanMomentary Wall Control 12 Volt

And as for hoses, Raritan's Sani-Flex is also top rated. Not only does it have a 10 year warranty against odor permeation, but it's also so flexible it can be bent almost as tight as a hairpin without kinking. RaritanSaniFlex hose Defender has it for < $10/ft, sold by the foot. Raritan Sani / Flex Sanitation Hose at Defender

You're welcome to give me a shout if you have questions I should be able to answer....


--Peggie

[belizesailor]

Originally Posted by Bayou Sailor

Thanks for the response belizesailor, but there is no room. I'm good with installing the tank and plumbing. I just didn't want to replace the aluminum tank if I didn't need to. Thanks!

Bummer. Yeah, ditch the alum tank, bad idea.

I had the welds fail on an old alum waste tank once when it was over full...not a pleasant life experience.