Installing a macerator

[David Hoch]

Peggy,I bought and read your book - quite well done and helpful. Thanks!I just bought a 2005 Hunter 260 and would like to be able to dump the holding tank at sea. Can (or have you already written about this?) tell me what components need to be added and generally how to connect them to make this a proper installation? I assume I need a macerator pump, through-hull, ball valve and perhaps a Y-valve. I don't think I need to be able to have it go from the toilet directly overboard. If waste always goes to the tank, I'm fine with it. I just need to pump it while at sea. I also will keep the deck pumpout functionality.Cheers,David HochLas Vegas, NVS/V Abundance

 

[Dave]

You need a y-valve

Hose from toilet goes to tank directly.Hose from tank to y-valve inlet. Two hoses from y-valve outlet. One goes to deck for discharge. The other goes to macerator. Hose from macerator goes to seacock for overboard discharge. To empty you open seacock, put y-valve in proper position and turn on pump.If you really want to be efficient just get a bucket and a seat that fits plus a short line. Go in the bucket and then drag the bucket in the water with the line to empty and clean it.My friends Bill and Leslie used to use this method all the time and it worked well for them. Dave

 

[Mick]

Macerator

You only need a thru-hull, ball valve, and a maceraqtor pump on a T off of the hose that goes to the deck. A "Y" valve goes between the head and the holding tank for direct overboard discharge.

 

[Peggie Hall HeadMistress]

Dave described almost everything you need...

However, if the tank will discharge below the waterline, you'll also need a vented loop in the line to the thru-hull, between the macerator and the thru-hull. If you plan to spend much time cruising in open sea, I'd also put a y-valve in the head discharge line to allow you to flush directly overboard...'cuz weather and sea conditions can sometimes make it difficult to empty the tank (the seacock should always be kept closed except when actually dumping it, which means you have to be able to get to it to open it)...and a full tank means you can't use the toilet.

 

[Sten]

Can I run to a macerator from a porta-potti tank?

I purchased a Thetford Aquamate porta-head last year and am really pleased with the design, the 6.1 gallon holding tank, and the electric pump for bowl cleanout. The Admiral luv's it! http://www.go2marine.com/frameset.jsp?servletPath=/g2m/action/GoBPage/id/88143F/&df=3 Now I want to use the pump-out feature but run to a macerator and discharge at sea thru the v-berth seacock. Any suggestions?Sten

 

[Peggie Hall HeadMistress]

Sure...plumb the same as any other tank

One thing to keep in mind, though...a macerator pump moves 12 gal/min...your portapotty only holds about 6 gals...so a macerator will empty it in about 30 seconds. Unless you pay very close attention, you can run the macerator pump dry too long and fry the impeller in it.

 

[David Hoch]

Macerator Install

Peggy,I'm planning this project now and have purchased the macerator pump. The instructions say to include a ball valve on the inlet side of the pump. This makes sense and makes me wonder if I need a Y valve in the line from the tank or just a T since both lines won't be used at the same time.I have an additional question - when connecting a thru-hull to a ball valve, is the thru-hull a pipe thread? If not, how does is seal when connected to a pipe thread like on the ball valve?Have you seen the web site for titanium thru-hulls? Seems like a good idea...DavidS/V AbundanceH260

 

[Peggie Hall HeadMistress]

Y-valve can serve same function as ball valve...

You'd only need a ball valve if you use a tee instead of a y-valve in the tank discharge line...to provide a shut-off of flow from the tank when the macerator needs service. The y-valve accomplishes the same thing and keeps the CG happy...kill two birds with one stone.The thru-hull should already have a ball valve on it--the seacock. I would not connect anything but hose directly to the tank, macerator OR the thru-hull...'cuz boats flex and take shock in heavy seas, which will cause the weakest link in any connection that isn't "cushioned" by some hose to crack.

 

[Paul]

DIY Boat Owber 2004-4

has an article on this that uses 3 ball valves and no Y valve. The author of this article says that when he used the traditional Y valve system he had a lot of problems with the macerator pump clogging up periodically. His solution (no pun ) is to have all the waste go into the tank. On the output of the tank is a T joint that has the long part of the T going to the deck fitting for pumpout. Straight through the T goes to a 1 1/2" ball valve (#1). The output of this ball valve goes to a reducing T - 1 1/2'X 1 1/2" X 3/4" . Straight thru the 1 1/2" part of this T goes to the macerator pump. The 3/4" side of the 2nd T goes to 3/4" ball valve (#2) that has a 3' garden hose attached to the other side. The output of the macerator goes to the Thru-Hull ball valve (#3).For dockside pumpout or CG check) all the valves are closed.To pump overboard open valve #1 and #3. After pumping overboard you clean out the macerator by closing valve #1 then put the garden hose in a bucket of water and run the maerator pump until the bucket is empty. This rinses the pump, leaving it full of clean water and absolutely ensures successful operation the next time.My explanation sounds complicated but if you draw a picture of it its actually very simple and if indeed clogged macerators are a big problem this sounds like a good idea.

 

[David Hoch]

Macerator

Thanks, Paul - I think I have a clear picture of what you're saying.Wouldn't it work just as well to use the marine head to pump a few gallons of water into the tank instead of another hose in the system for cleaning the pump? I suppose the down side is wear and tear on the head.

 

[Peggie Hall/HeadMistress]

Why would a y-valve cause the macerator to clog?

And how would 3 valves in the system be able to reduce any potential for clogging better than 1 y-valve?The whole point of that "Rube Goldberg" plumbing solution is only to provide a means of rinsing the tank as it's pumped out. That's much easier to do: simply install a second discharge fitting--easy to do with a little doodad called the Uniseal (see it here: http://www.aussieglobe.com/avs96.htm)and deck pumpout fitting...stick a hose--not the same one you use to fill your water tanks!--down the second fitting while you're dumping or pumping out.Or, even simpler yet...make the small effort required to rinse out your tank when you do use the pumpout. But 3 valves, two tees and at least one (I lost count) reducing adapter in a system that should only require simple y-valve is over-complicating a system that should be very simple...nothing more than a single line with a y-valve in it.When it comes to plumbing--ESPECIALLY when it comes to plumbing--the simplest way to do anything is the best way.

 

[Peggie Hall/HeadMistress]

Paul...to answer your question...

Pumping water into the tank via the toilet during pumpout doesn't do much...'cuz it sends water into the tank at the top, instead of directly into the bottom to stir up any sludge. So the solution is, a few times a year, use the pumpout...after the tank is empty, put a few gallons into the tank via the deck pumpout fitting--which is at the bottom of the tank...pump that out...repeat...repeat...repeat...till you're only pumping out clean water. Or--While dumping at sea, use your washdown pump to put water into the tank down the deck pumpout thru-hull. The point is, you don't need a bunch of valves etc to maintain your tank...just a little effort once in a while.

 

[Phiggins]

Peggy you should keep an open mind

First its only one more valve than your solution (both have the thru hull valves) and there is only two T valves one a reducer. And you're suggesting installing some other gadget so who has the "Rube Goldberg" solution. Your suggestion about flushing the tank when you do a pumpout is only good if you pumpout. That probably rarely happens if you are doing a lot of cruising. Take time and draw the picture, it is simple.

 

[Phiggins]

Let's compare the 2 valve to the Y valve

setups. Forget the thru hull valve which is common to both methods.First let's define the problem: When you do a macerator pumpout it will leave behind some sludge in the macerator. If you don't clean this out, it will harden and gradually buidup with every macerator pumpout. Eventually the buildup will beome so great that either the pump will fail or fuse will blow after which you have to take the pump apart (Yecchh) and clean it.Solution: flush the macerator pump after every usage with clean water. How do we do that with each of the setups -With the 2 valve setup: Close valve #1, open valve #2, put hose in bucket of clean water, run macerator until bucket empty, close all valves, go have glass of wine.With the Y valve setup: Turn Y valve to deck pumpout position; go up on deck; use washdown pump (which by the way is now another essential component in the "simple" Y valve setup) to put some water in the tank and stir up the sludge; go back down below; move Y valve to macerator posiion; run macerator until tank is empty.But you know for sure that the water from the tank is not clean because of all the sludge you stirred up, so repeat: Move Y valve, go up on deck, put water in tank, go below, turn Y valve, run macerator.Just to be sure you probably do this a few more times but you're never really sure that you are pumping clean water are you.Meanwhile 2 valve guy has finished 3rd glass of wine and is well into a snooze.

 

[Peggie Hall HeadMistress]

Not sure where you're cruising, Phiggins...but

If anywhere near your home port, you shouldn't be using a macerator at all 'cuz it's illegal to dump a tank in any U.S or Canadian waters waters within about 600 miles of it...you must be at sea at least 3 miles from the nearest point on the whole NA coastline to dump a tank legally.As for keeping an open mind...some 20 years of experience in the marine potty biz with literally thousands of boat owners and systems has taught me that the more complex the system, the more likely it will be that it will cause more problems than it solves...not necessarily because the system is a bad idea, but because owners rarely maintain 'em. Sure, that system makes it easier to flush out the tank than doing it at a pumpout...but how many people will actually do it religiously? How many will make sure the valves are kept lubricated vs. how many will just leave 'em in the overboard position so long they freeze up and can no longer be opened or closed. Most of 'em--especially blue water cruisers--don't even maintain one y-valve...they leave it open (and the thru-hull) all the time. Expecting 'em to maintain 3 ball valves and ever actually flush out the tank until the macerator does clog up is a bit unrealistic in my considerable experience...and by then the valves are likely to be stuck too.So the simpler the system, the better IMO. However, I can only advise...it's your boat to do anything you want to, even if it's illegal. I can only advise about that too.

 

[Phiggins]

Ilegal?

When did this discussion start talking about legal issues? If you are so concerned about the legal aspect of this why are giving all the advice about installing macerators in the first place.I respect all your experience and great advice but sometimes if its anything that's not "Peggy's idea" you have a way of putting it down.

 

[Peggie Hall HeadMistress]

Why do I give advice about installing macerators?

Because it's legal to use them to dump a tank at sea beyond the "3 mile limit," and because many here have their boats in coastal waters and can easily get more than 3 miles offshore...in fact, often do, not only just to dump their tanks but sail in open water. If someone chooses to use one illegally, it's their problem if they get caught doing it, not mine...'cuz it's up to each owner to know the laws.And if discouraging someone from doing something I know from experience is likely to cause 'em more problems than it solves is "putting it down," I dunno how to solve that problem...I guess it's all in the eye of the beholder.

 

[Phiggins]

You win...

I give up. The are no other ideas greater than yours. We're all a bunch of dummies. Hail to the Head Mistress may she reign forever.

 

[Jim Seamans]

You're right Phiggins - Peggie knows her shit!

nm

 

[Malcolm Young]

I need some confirmation

PHiggins - Your location in Toronto I think is confusing things. I assume that you were not talking about using the macerator in the Great Lakes as it is totally illegal no matter where you are in the Great Lakes. By law the discharge of my macerator blocked and the hose cut.I think it is quite proper to point out to the general readership that the above is a fact. There are some that do not know. This past summer I heard someone call (on the VHF) three marinas in the area of Little Current (Georgian Bay - Lake Huron) asking if they had macerators as his didn't work any more. Of course none of them have macerators as there is no way to legally use them. It would seem clear that he didn't know. I wish I had said something in hind site. If I had seen the boat in an anchorage later on I would have said something.This is scary for those of us that love the North Channel for its clear/clean waters (or any where in the Great Lakes). I see lots of boats with home ports in tidal waters cruising in the Great Lakes. It is apparent that some of them may not know it is illegal to discharge the black water overboard.