Holding Tanks

[SloopJonB]

Vertical tanks are better than horizontal tanks. Can you do one sort of like a backrest

Pretty much what I had in mind

 

[andykane]

Another local option is Century Plastics. Over here Trotac stocks their tanks and will spin-weld fittings wherever you want - must be someone over your way that does the same.

You sounds pretty set on a holding tank but I'll join the chorus for a composting head. My C-Head was just so easy.

 

[Calling Elvis]

No one has mentioned bladder tanks yet. My Alerion came with one (I forget the brand) and I have no complaints. Bladders are widely used for fuel and other nasty stuff, so the technology is there. They probably don't make maximal use of the space available, but it is easy to see when you need a pumpout with just a glance. The fittings may not be best positioned for gravity drainage, but customization is possible.

We had a bladder on a previous boat. I was washing it one day and the bilge pump kicked on, which had never happened before. I smelled it before I saw it. The PO had patched a hole on the underside of the bladder, which failed. We replaced the bladder with another bladder and never had an issue, but I have to advise against ever patching a bladder.

 

[Foolish]

You'll notice that up here in Victoria, our shit doesn't stink. That's just how WASPy we are.

 

[Zonker]

Yes the Canadian waters look much cleaner and bluer

 

[SloopJonB]

We had a bladder on a previous boat. I was washing it one day and the bilge pump kicked on, which had never happened before. I smelled it before I saw it. The PO had patched a hole on the underside of the bladder, which failed. We replaced the bladder with another bladder and never had an issue, but I have to advise against ever patching a bladder.

I'm sure a bladder could work fine but I have a problem with having a big plastic bag of sewage on my boat.

 

[Hale Moana]

My boat didn't have a holding tank when I bought it. None of the Ronco tanks would fit where I wanted to put it. So I made one out of plywood and epoxy following the instructions from West Systems. That was almost 20 years ago. No problems. All of my connections are on the top of the tank.

 

[cje]

If only there was a "fix it" anarchy..

 

[Steam Flyer]

No one has mentioned bladder tanks yet. My Alerion came with one (I forget the brand) and I have no complaints. Bladders are widely used for fuel and other nasty stuff, so the technology is there. They probably don't make maximal use of the space available, but it is easy to see when you need a pumpout with just a glance. The fittings may not be best positioned for gravity drainage, but customization is possible.

The problem with using a bladder tank for holding sewage is that you are creating an anaerobic environment, which is even nastier than what normally breeds in there. Nobody likes to think about venting a holding tank but it's actually very important for multiple reasons including microbiology and for pumping in or out.

I'm sure a bladder could work fine but I have a problem with having a big plastic bag of sewage on my boat.

If you buy the good ones, they are incredibly tough. The Army drops "big plastic bags" of diesel fuel to mech troops in the desert. Yes they drop them low and slow but I think your average tank would not do as well plummeting from a C130.

 

[cje]

I would agree about the environment Steam but I not had personal experience using a holding bladder, only cleaning up after them and removing.
I started installing twin vents years ago going P/S where possible.

 

[Son of Hans]

My bladder, or I should say, my boat's bladder, is vented like any other tank.

 

[Grizz]

I use a vented bladder as well. I believe the bladder tends to permeate and slowly release odors overtime. I put a brand new one in a couple of seasons ago, with expensive hoses (Raritan Saniflex.) Bladder is a 25 gallon Venus Nauta. After the first season we began getting odors. The bladder is under the v-berth, so not ideal. If I can find a hard tank that fits, I’ll switch. Not a fun job.

 

[SloopJonB]

The problem with using a bladder tank for holding sewage is that you are creating an anaerobic environment, which is even nastier than what normally breeds in there. Nobody likes to think about venting a holding tank but it's actually very important for multiple reasons including microbiology and for pumping in or out.


If you buy the good ones, they are incredibly tough. The Army drops "big plastic bags" of diesel fuel to mech troops in the desert. Yes they drop them low and slow but I think your average tank would not do as well plummeting from a C130.

I based my attitude on experiences with waterbeds in the 70's.

 

[Steam Flyer]

I based my attitude on experiences with waterbeds in the 70's.

Mixed reviews on that. I only had two. One sprung a leak after a couple of years (on a seam of course) and one was fine until long after I sold it. But they also were prone to microbiology problems if you recall... and I don't mean the sheets...

 

[seaker]

I raced on a boat that had a bladder. The boat shop that installed it cut the bottom hole too large and the fitting came off with a full bladder. Fun to clean up the night before a race weekend. They did replace it with a tank for free when I showed the boat owner the instructions and how far off they where off.

 

[Go Left]

If you want to know about holding tanks, talk to an expert

 

[Great Red Shark]

Cardboard works, or thin doorskin ply hot glued together.

Ah, yes: C A D

Cardboard Aided Design

 

[Fah Kiew Tu]

Ah, yes: C A D

Cardboard Aided Design

Yep. Always use cheap stuff for the prototype. Especially if you're like me and get to the Mk 3 (or later) version before you're happy with it.

I recently got to the Plan C Mk 3 version for my autopilot motor mounting position...

FKT