Macerator Pump or Diaphragm pump for overboard discharge

[Minggat]

Another vote for manual gusher pump.

[Sailshabby]

Originally Posted by sailcrazy

We have a similar system, except ours is an electric toilet with B/I macerator; discharge goes to a "Y" valve, and then to a holding tank or overboard. But the macerator pump we had installed would not empty the holding tank, even though the vertical lift was less than 2'. We tried everything, including rebuilding the pump, and then changing pump manufacturers.....it still did not work. I bought and installed an electric waffle pump, and it works perfectly! Don't understand all I know about the system, but I'd strongly recommend a waffle pump-manual or electric.

Waffle pump? Not sure I’ve ever heard of this.

[Capt. Hack]

There a hose fitting on the deck of my boat . It is a wash down . Connect hose turn on pump wasdown anchor fish guts or whatever. it pumps saewater

[sailcrazy]

Waffle pump = diaphram pump. Sorry, that's the name I've always heard and used. But definitely, it is NOT a macerator pump.

[felizcortez]

See attached pictures that show the deck fill, vent, and second (the second hose that looks like a garden hose input). I also included other pictures that show where they go into the holding tank.

if i want to expand to say a 1 inch hose to increase air flow, how do I deal with the old attachments to the tank, Would I drill new ones and use a uniseal or cap or plug those old holes?

Sounds like everyone thinks the diaphragm pump is the way to go. I'm going to check out sizes since I may need to get an electric one because the locker is a bit slim where this is all installed.

[peghall]

if i want to expand to say a 1 inch hose to increase air flow, how do I deal with the old attachments to the tank, Would I drill new ones and use a uniseal or cap or plug those old holes?

You'd use a Uniseal and use threaded plugs wrapped in plenty of teflon tape to seal up the existing ones.


--Peggie

[daveNZ]

Our manual diaphragm pump works well. We have same as Marathon 1150...which I’m recommissioning after 17 years (only seasonal coastal cruising). So Whale Mk5 manual diaphragm pump to empty the holding tank. After cleaning!!! the Whale pump diaphragm still looks 100% and the joker valve sits a little open, but it works, so we’ll stay with a diaphragm pump.

Incidentally a new diaphragm and valves, NZ$100, complete new pump NZ$135!
An electric pump would be nice to do even more flushing (I bought Peggie’s book; highly recommended) but that’s about NZ$500++

Question: holding tank outlet is 1.5” threaded elbow with an o-ring. To try and ensure no leaks!!! would anyone add Teflon tape, Loctite 5331, to the threads, or just let the o-ring do its job? I don’t want to do this again for a while! Many thanks.

[felizcortez]

Originally Posted by peghall

if i want to expand to say a 1 inch hose to increase air flow, how do I deal with the old attachments to the tank, Would I drill new ones and use a uniseal or cap or plug those old holes?

You'd use a Uniseal and use threaded plugs wrapped in plenty of teflon tape to seal up the existing ones.


--Peggie

Thank you. Do the plugs need to be a certain type of plastic? Any particular recommendations?

If I switch to a Diaphragm pump does it matter if the waste isn't macerated from the toilet?

To put in the vent through hull, I think I'm going to need a. 90 degree fitting to allow me to install the hose.

Do you think it's worthwhile to just try a better throigh hull than the fuel tank vent that I have now, or should I just switch it out to a 1 inch line and through hull?

[Cat36Mahalo]

I went with the diaphragm pump - whale sewage pump. Works great. I don’t have a Maserati head.

[Knotical]

Originally Posted by CassidyNZ

Perhaps the fitting with hose connection is intended to introduce fresh water to the holding tank for flushing/washing-out operations? It would worry me ever so slightly though, that I may be using a hose to take on drinking water that has just been connected to someone else’s holding tank.

A boater recently advised me to never use the existing public water hose to fill our water tanks - I disconnect their hose, connect mine, fill the tanks and reconnect their hose before departing; at least you know what the hose is being used for.

[peghall]

Do the plugs need to be a certain type of plastic? Any particular recommendations?

Plain ol' schedule 80 pvc, available from the plumbing department in most big box hardware stores.

If I switch to a Diaphragm pump does it matter if the waste isn't macerated from the toilet?

Nope, because solids are 75% water, so they dissolve in the tank very quickly and quick-dissolve TP.

To put in the vent through hull, I think I'm going to need a. 90 degree fitting to allow me to install the hose. Do you think it's worthwhile to just try a better throigh hull than the fuel tank vent that I have now, or should I just switch it out to a 1 inch line and through hull?

A 1" vent line would be ideal, but whether to upgrade or just replace the thru-hull is up to you. But whichever you do, I'd rather see a long gentle sweep in the vent line than a sharp 90 at the thru-hull.

--Peggie

[desodave]

We cruise in an area where there are no pumpouts, and have a diaphragm pump. Fourteen years, no problems yet. We also have a manual toilet and use Noflex digester treatment in the tank. The particle size coming out is mostly as a "cloud" with no particle size I'd be worried about.

[felizcortez]

I purchased the Sealand T-series pump today. It should be here in a few days. I'm going to need to do some redo some of the plumbing on the discharge line tot he seacock - but it should be relatively simple.