Adding a larger holding tank

[Pelch]

I'm trying to figure out how to replace my head with a wet bar. Suggestions are welcome.

I bought an 02 in 2022. I want to take out the port a potti and replace it with a holding tank. If I can, use sink drain thruhull as a waste clean out and also add deck clean out. I've looked in mods but haven't really seen much as most members seem to sail on oceans. Mine is used on prairie lakes.

[leefrankpierce]

Unsure if you are removing the porta all together, however I presume it would help you to know what is behind the fiberglass.
See post https://macgregorsailors.com/forum/view ... hp?t=27985
for pictures of my bathroom.
Or more direct if this works.
https://postimg.cc/hf1S9Y8j
https://postimg.cc/xc103R63
I removed the sink,wall, floor so that I could gain enough room to almost stand up and put clothes back on.
I put some PVC flooring down to make a place to mount the porta, however the blue areas are raw hull.
The ballast tank runs under the door frame and into the bathroom area, so you must be very careful how deep you cut when removing the floor.
In my picts the porta mount is right were the sink was and you will see the drain fitting I have capped off.
Under the floor it is open to the rear and forward bilge area, notice the gap above my flooring.

[Starscream]

I bought an 02 in 2022. I want to take out the port a potti and replace it with a holding tank. If I can, use sink drain thruhull as a waste clean out and also add deck clean out. I've looked in mods but haven't really seen much as most members seem to sail on oceans. Mine is used on prairie lakes.

I installed a flushing toilet using two 9-gallon Moeller tanks underneath the forward dinette seat. Originally I used one for flush water and the other for holding, but with a family of six on board, 9 gal holding just isn't enough. Last spring I converted both tanks to holding, and installed smaller 3 gallon flush-water tank under the starboard V-berth. This year I will add a shut-off valve so that the flushwater will only be drawn if needed (number 2 or a quick rinse). Otherwise, too much flushwater ends up in the holding tanks. Also planning to add a side-spray in the bathroom head that is plumbed to the boat freshwater, that can be used to "encourage" an important flush. Boat toilet necks are narrow just before the macerator.

Tanks were similar to this: https://www.entrepotmarinemart.com/en/9 ... k-moe40209. They may even have been exactly this tank, but I can't confirm dimensions right now.

Flushwater could also be sucked up via a thru-hull, but I didn't want to cut any holes in the hull.

Pumpout is done through a deck fitting.

[Pelch]

Not looking to cut out anything or take away any storage space. Looking to remove port a potti, put holding tank in that area that is 3/4 waste holding, 1/4 fresh water holding. This way I can have larger capacity for waste, higher seat for toilet. Put valve at bottom corner of tank and run to thru Hull under sink. If I can seal that off, I can use it at RV dumps as I come across these more regularly. Most lakes around here don't even have a jetty let alone on water waste disposal.

[Russ]

I would check your local regs. If I recall Canada has some tricky rules for holding tanks. That may be by province.

Also.. be careful putting holes below or near the waterline.

[Pelch]

Yes, I've heard Ontario demand no porta potties and deck clean out, but that doesn't apply out west where I am. I don't want to cut any holes in my boat, want to use existing thru Hull if it's possible. Buy a fitting like gas cap fitting that can be locked and seals it.

[Gazmn]

Have you considered a Composting toilet?

I Really appreciate the convenience and built in storage of mine.

[Starscream]

Yes, I've heard Ontario demand no porta potties and deck clean out, but that doesn't apply out west where I am. I don't want to cut any holes in my boat, want to use existing thru Hull if it's possible. Buy a fitting like gas cap fitting that can be locked and seals it.

I'm not sure that using the existing thru-hulls is a good idea for toilet drainage, if I understand your intentions correctly. There's no way I would mix grey-water and black-water systems on a boat. You can do that in a house because there are P-traps in the sanitary drainage system that create an odor seal, but on a boat that's not gonna work well, IMO. In drainage systems where there is a chance that the P-trap runs dry, a drip-system is supposed to be used to keep the P-trap charged. In cottages that are not permanently occupied, owners will sometimes drop oil into each drain to lower the evaporation rate of the water in the P-trap to try to make it through the unoccupied season without breaking the odor seal.

Better to have a deck-mounted pump-out, with the proper screw-in fitting for an evacuation pump. Again, in my opinion. Imagine opening that gas-cap fitting on the side of your boat, with a mix of black and grey water waiting behind it.

Your boat, your rules. (Just to make Ray cringe some more)

[Jimmyt]

Your boat, your rules. (Just to make Ray cringe some more)

[NiceAft]

Fair is fair, I can take it.

[Pelch]

I would take out the sink and install lock out valve right by tank. Grey water is not allowed in fresh water lakes here. But I've been looking more at those composting toilets and think that will be best solution. Thanks for the suggestions.

[OverEasy]

An interesting aside ….
https://towndock.net/captains-blog/trag ... palm-coast

[NiceAft]

[Gazmn]

If you do go forward with using a composting toilet, I’ve found This Blog very useful.

[tomradams]

I would really suggest the Nature's Head Composting Toilet. Best $1K I have spent so far on my 2002 .