Let's talk Macerators...

[Rick Allen]

I'm not happy with the way the macerator is installed on my 1988 MKI. I know this has been discussed before in the forum, but I haven't yet seen a good solution. With the way it's installed now, effluence will continually sit in the short hose between the holding tank and the macerator and accelerate permeation. Since I'm currently replacing all my sanitary hoses, I'm thinking of perhaps using PVC instead of hose between the tank and macerator or just not replacing the macerator at all and plugging the fitting from the tank.

My main sailing area is SF Bay and I do a little coastal cruising. In the 12 years I've owned this boat, I've only used the macerator once.
I tend to believe times have changed since the macerator was installed 28 years ago. Pump out stations are more plentiful now than they were back then, and with the rapidly increasing number of "No Discharge Zones", I don't see myself using the new macerator much. I don't take long voyages. If I install a new macerator, effluence will just sit in the short hose and increase its permeation time.

Installing a short schedule 40 PVC pipe would work if I could align it correctly and work out the fitting issues. Has anybody done this? Any tips?

Here's a link to some photos of the area and my progress so far. Everything is out and I've used Bilgekote to brighten up some of the spaces.
http://public.fotki.com/Sailorick/sv_painkiller/holding-tank/

As Stu would say: Your boat, your choice....

Thoughts?

Thanks!

Rick

[chuck53]

2 years ago, my macerator pump crapped out and halfway thru the installation of a new one, it hit me...why bother.  I capped off the hose and sent the new pump back for credit.  Haven't missed it a bit.

[Jon W]

Did you use anything special to clean the holding tank top or just soap and water?

[Rick Allen]

Jon, I cheated.
I cleaned the top of the holding tank like crazy with 409, then I applied a few coats of Rust-Oleum flat black spray paint for plastics.
Looks good so far!!

[Ralph Masters]

Rick,
I have an 87 and it's identical set up as yours with one exception. I have a "T" installed in the hose going from toilet to tank and a direct overboard valve.
Changing out that pump is the single hardest job I have done on the boat. When it needs changing again, I will just remove and not replace it.  I used a short hose with a hose barb and threads and just capped the end.
Nice paint job,

Ralph

[Jon W]

Hi Rick,
    It looks great, like a new tank.

[KWKloeber]

My setup on the C-30 was the tank discharge hosed to the deck pumpout fitting, with tee in that line for the macerator.  I never used it. but problems except with the CDN CG --  it had to be locked out or physically removed (Lake Erie.) 
For a couple years I plumbed it as TANK > Macerator -> deck pump out.   It was fine except once it locked up on a 2-week trip, and then I was stuck unable to pump out.  I quickly changed that plumbing.

I replaced the OEM with the best Shields sanitation hose and it will outlast you and me -- use that hose and you won't have a problem.

The tank/hose doesn't empty fully because the vacuum breaks once once the poop level draws down to the top of the tank outlet.  A trick I learned from my stinkboat bro -- I installed a wet trap off the tank outlet, so I draw a vacuum until the trap is emptied.  It's fabricated out of 1-1/2 pvc and has an "emergency" drain plug.  The drop was enough from the tank to the bilge (ie, bottom of the trap) so that the trap works.  Works like a charm (so far - knock on fiberglass.)  Have no idea whether a 34 could be fitted that way.

-kk

[Stu Jackson]

I replaced my pump last year, not knowing I would be moving to Canada.  There are essentially NO pumpout facilities here in British Columbia.  We used the macerator pump all the way up the coast, since we were well offshore.  I wouldn't remove it, since the next owner may want one.

IMHO, pumping everything into the tank and then out, either way, makes little sense to me.  Either the stuff should go directly overboard OR to the holding tank.  My setup is:  head > overboard valve OR to the tank (with a valve at the tank).  That gate valve, the ONLY one on my boat, was put in by the PO.  I've replaced the valve many, many years ago, and only have had to replace the guts of the valve once since then.  I still have new backup guts for the gate valve just in case this one dies on me, because salt water isn't very good to the stem and gate inside the valve.  I tried once to replace the gate valve with a plastic ball valve, but there wasn't enough room.

The macerator pumps from a separate outlet from the tank.

[KWKloeber]

IMHO, pumping everything into the tank and then out, either way, makes little sense to me.  Either the stuff should go directly overboard OR to the holding tank. 

Exactly right, and some (not all of them came plumbed that way -- maybe a PO spec or being an inland instead of coastal boat?  Who knows?)  The only benefit of first to the black water tank is that you can choose when to dump poop (appropriate tack, etc.)  otherwise it's unnecessary.  All the C30s I have seen have only a single tank outlet, hence with the macerator tee'd into the pump out line.

P.S. The unplumbed seacock in my pic is for the macerator (still in position but unused.)

-kk

[Rick Allen]

Thanks for all for your great comments and suggestions.

I agree that a good route would be: Toilet to Y valve, then either to tank or thru hull. IIRC, my only existing thru hull is 1"ID. This might present an issue going from 1-1/2" to 1" at the Y valve. The existing thru hull was the 1" discharge from the macerator.

Ken, I love your setup with the trap, but I don't see that happening unless I raise the holding tank and that presents a million more problems.
I guess I'll look into the fittings needed to replace the small hose between the tank and the macerator with sch40 PVC.

It's always good to get some differing opinions!

Thanks again.

Welcome to Canada Stu! We miss you down here my friend. 

[John Langford]

Interesting plumbing discussion. However, I am afraid I have to take exception to Stu's heartfelt but inaccurate report on pump out facilities in his adopted neighbourhood. Between Victoria and Nanaimo in the Gulf Islands area he soon will be exploring there are at least 12 pump out stations. In addition to the 9 listed on the following website there are facilities at Tsehum Harbour (that's harbour with a "u" Stu), Ganges, and Telegraph Harbour on Thetis Island. There are many more on the mainland in the Vancouver area and north on the Sunshine Coast. Plenty of opportunity to do the right thing.

https://georgiastrait.org/work/cleanmarinebc/pumpouts/

[Stu Jackson]

I told you our brethren up here would be helpful. Thanks again, John.