Adding pumpout and Uniseal port

[mike75bug]

I am working on getting my boat ready for this summer and need to update my sanitation system. Currently the system can 1) Discharge directly overboard 2) Discharge to a holding tank under the cockpit sole 3) Using a macerator pump attached directly to the holding tank, discharge holding tank overboard.

I have attached a basic diagram of the current setup, but have excluded intake and the fact that all thru-hulls have seacocks on them.

So, here are my questions:
1) Can I use a uniseal to put in a second discharge from the tank low on the tank or do they need to be installed in the top of the tank with a dip tube (I have no clearance above)?
2) I was looking at using a dometic elbow that comes with a Uniseal. What keeps these elbows in place in the uniseal? It would be a mess if one came out of the uniseal.
3) Am I legal? Without a diverter on the discharge (as you recommend to do to simplify things) I can't lock off my overboard discharge from the macerator.
4) Is there a better way to do this? I just need to be able to pump out at the marina since we are moving aboard this summer. Last year's West Marine catalog showed a diverter /after/ the macerator to a through-hull and deck fitting, but that seems scary to push sewage at the pump out device.

Thanks for your help,

Mike

 

[Peggie Hall HeadMistress]

Before we go any futher, I need to know:

Have you really installed the system you describe on a 19' boat?????

 

[mike75bug]

Nope, I am installing this in a Bristol 27

Have you really installed the system you describe on a 19' boat?????

Sorry, this is on my 1968 Bristol 27. I bought it last year and am working on restoring her. She has sat for the past 5 years on the hard before I bought her.

On my 19' O'day we have a porta potti Very simple.

 

[mike75bug]

Boat photos

Have you really installed the system you describe on a 19' boat?????

I also now added a link to my profile to a website of boat photos of how she was when I got her and my profile shows her current condition after a lot of work painting. I didn't realized people read that often and I had not updated it.

The head is being replaced probably with a new jabsco manual head. I should have done the raritan update, but it was too late and I had already thrown the headmate away when I found your update recommendation on this forum.

Mike

 

[Peggie Hall HeadMistress]

Whew! You had me worried!

Now...to answer your questions...

You CAN use a Uniseal to add a fitting low in the tank, but the folks who make the Uniseal don't recommend it and neither do I because even a little stress on the fitting can cause it to leak. As for the Dometic fitting, it's VERY easy to cobble up everything in it for a fraction of the price they want for it.

What keeps the pvc straight fitting or elbow in it? The Uniseal is a rubber "grommet" that grips the pipe in it VERY tightly ...the seal is as reliable as any rubber gasket would be.

You're legal. The law doesn't require that any valves be in the system, not even seacocks ...it only requires that any valves that are installed be "secured" using one of the methods prescribed by the CFR.

You asked it there's a better way...and IMO, on a boat that's only 27' there is: replace the whole system with a 5-6 gal. "MSD" portapotty. We recently had a discussion about 'em:
http://forums.sbo.sailboatowners.com/showthread.php?t=123402

Additional advantages: It'll hold 50-60 flushes...you'd need a 30 gallon tank to hold that many from a manual marine toilet....that's gonna eat up 20-25% of your storage.

You can still dump it at sea if you put a y-valve and your macerator in the pumpout line. (I agree with you that the y-valve belongs ahead of the macerator, not after it! That had to be a mistake in the WM catalog)

And one more reason that really matters to someone who's planning to live aboard for the summer: you regain a BUNCH of storage now being used by the tank and plumbing.

IMO, it's a perfect KISS solution that costs less than the new Jabsco piece of junk that isn't likely to give you even one full summer of trouble-free service. There are plenty of other places to spend money on a "project boat" (been there, done that...so I know!).

You can buy everything you need from the online store here: sbo.com plumbing I recommend the Thetford 365 MSD and Trident 101 hose.

That's my $.02 worth...Whadaya think?

 

[mike75bug]

A 365 MSD was my original plan when I got the boat. A friend of mine had convinced me against it because of the small capacity (5.5gal vs. my current holding tank which I think is 12gal). But I guess when you also calculated in the amount required to flush the lines clean after flushing it makes sense.

I will need to test the macerator to see if it even works. I have not tested it since buying the boat.

Do you recommend any manual pumps for this? If the macerator is dead or maybe even if it is not, I would want to replace it with a manual pump.

Also, I already have a 365 for my O'Day, I was hoping they sold a conversion kit but it looks like they don't unless you know anything that I don't.

Thanks again for your advice,

Mike

Now...to answer your questions...
You asked it there's a better way...and IMO, on a boat that's only 27' there is: replace the whole system with a 5-6 gal. "MSD" portapotty. We recently had a discussion about 'em:
http://forums.sbo.sailboatowners.com/showthread.php?t=123402

Additional advantages: It'll hold 50-60 flushes...you'd need a 30 gallon tank to hold that many from a manual marine toilet....that's gonna eat up 20-25% of your storage.

You can still dump it at sea if you put a y-valve and your macerator in the pumpout line. (I agree with you that the y-valve belongs ahead of the macerator, not after it! That had to be a mistake in the WM catalog)

And one more reason that really matters to someone who's planning to live aboard for the summer: you regain a BUNCH of storage now being used by the tank and plumbing.

IMO, it's a perfect KISS solution that costs less than the new Jabsco piece of junk that isn't likely to give you even one full summer of trouble-free service. There are plenty of other places to spend money on a "project boat" (been there, done that...so I know!).

You can buy everything you need from the online store here: sbo.com plumbing I recommend the Thetford 365 MSD and Trident 101 hose.

That's my $.02 worth...Whadaya think?

 

[Peggie Hall HeadMistress]

Go with the Whale manual pump

Any macerator--or any other equipment--that's sat unused for 5 years isn't gonna work for long, if it even works at all...'cuz when electric motors sit, the lubrication in 'em settles, allowing corrosion. Then, in a macerator, the impeller will be worthless--dried out and brittle.... So I'd scrap it without even trying it.

A friend of mine had convinced me against it because of the small capacity (5.5gal vs. my current holding tank which I think is 12gal).

He obviously hadn't considered anything except the tank size...clueless about flush water useage.

But I guess when you also calculated in the amount required to flush the lines clean after flushing it makes sense.

There aren't any lines between the bowl and the tank...it's a direct drop. The only water needed is enough to rinse the bowl. And btw, you'll need less if you add a little to the bowl ahead of solids, even if you have use a cup.

I already have a 365 for my O'Day, I was hoping they sold a conversion kit but it looks like they don't unless you know anything that I don't.

Weellll...If you're creative, this might be a good place for a couple of Uniseals--1" for the vent and 1.5" for the pumpout--and a couple of pvc straight or 90 fittings (available from any hardward store). :dance: I think you can buy hold down brackets for it if you don't have 'em. We can work on this via email if you want to.

 

[mike75bug]

Thetford conversion parts

I just got off the phone with service at Thetford. I can convert my 365 to an MSD by purchasing the hold down kit (#35801) and the pumpout spout (#35803).

I will do that and get a smaller one for the O'day if we keep it (way too much storage and it was unnecessarily bulky.

Hopefully this info will help someone else.

Mike

I already have a 365 for my O'Day, I was hoping they sold a conversion kit but it looks like they don't unless you know anything that I don't.

Weellll...If you're creative, this might be a good place for a couple of Uniseals--1" for the vent and 1.5" for the pumpout--and a couple of pvc straight or 90 fittings (available from any hardward store). :dance: I think you can buy hold down brackets for it if you don't have 'em. We can work on this via email if you want to.

 

[Peggie Hall HeadMistress]

That's good info!

I've saved it...Thanks! Btw...how much $$ do they want?

And a good idea to put a smaller one on the O'Day...'cuz a full 5 gallon tank weighs over 40 lbs, which is a LOT to carry off a boat to dump it on land.

 

[mike75bug]

No vent line needed? Confusion???

I don't know a price yet. Their parts department is closed.

I am worried though. I had talked to their tech support before and they said you can't convert the unit. Today I was looking at the online parts manual, saw that it looks like an easy swap and had the part numbers in hand.

I called Thetford tech support and asked if I could use those parts to convert and the person I spoke to said "Yes, no problem."

I called back and spoke to the same person because the online manual has no information about the MSD model. I was asking what size vent hose to use on it and the person told me that you don't need to connect a vent hose because the vent has a duck bill in it and it is just to keep the tank from collapsing when being pumped out.

It would be cool if this is true, because I don't have to drill another hole in my boat, but I am doubtful. I guess when I get my pump spout I will look to see.

If it does have a duck bill setup the tech was right and there is no need to attach a vent line and vent it out of the boat.

- Mike

I've saved it...Thanks! Btw...how much $$ do they want?

And a good idea to put a smaller one on the O'Day...'cuz a full 5 gallon tank weighs over 40 lbs, which is a LOT to carry off a boat to dump it on land.

 

[Peggie Hall HeadMistress]

Weeeellll....maybe

I was asking whathrut size vent hose to use on it and the person told me that you don't need to connect a vent hose because the vent has a duck bill in it and it is just to keep the tank from collapsing when being pumped out.
ly prono
My first reaction was "whaaaa???" 'Cuz flushing a manual or electric toilet against a blocked vent will pressurize the tank. But pulliing a lever to open a trapdoor in the bottom of the bowl isn't gonna make that happen in a self-contained MSD system. However, the lack of air exchange will definitely create odor. But if it can't get out, who cares? But maybe it can...every time you pull that lever...

So here's what I'd do: install it without a vent line/thru-hull...see how it works. If you're happy, I'm happy. If you're not, install the vent line and thru-hull.

I love it when the answer is simple. :dance: