Plumbing System Rebuild

So as I'm finally getting all of the serious stuff fixed and in great working order on my 20-year-old new-to-me boat, I'm starting to look at some comfort / appearance projects.

First being the plumbing. The head, even with a cap or two of bleach, seems to smell any time I run water through the sinks (im assuming as water goes into the holding tank, air goes out, through the drains, resulting in poo-gas in the cabin).

I've also heard that over time, the hoses and plumbing just absorb the poo-gas and are forever tainted.

SO,

how hard is it to pull out & replace all the plumbing from the head & sinks to the holding tank? Is the tank itself replaceable, or is that built-in to the boat?

I realize this might be quite the undertaking, and I'm certainly not afraid of the work, I'm just wondering if anyone has done it, or if this is completely unheard of / impossible.

Any input would be appreciated!

Re: Plumbing System Rebuild

I don't know anything about your boat, but it'd be very odd for the sinks to drain into the black water tank. I know that some boats have 2 holding tanks- one for black water and one for gray water (that's the output from your galley and head sinks).

On my boat, the galley sink drains directly overboard; and the head sink and shower drain into a sump- a box below the cabin sole that's fitted with a pump and float switch. When the sump fills the water is pumped overboard. IF you have a shower sump like that, it can get smelly because water sits in it. You can address that by flushing a lot of fresh water through it, then treating it with something like Raritan CP (clean potty).

Now, it is true that the hoses and tanks that service the toilet and black water tank can become permeated over time. Ease of replacement depends on how the waste hoses are routed, and they ARE stiff. It's not a pleasant job. You can add a filter to the black water tank's vent line, which is probably the easiest thing to try. I've been having some success cleaning mine up this way:

1. Pump out the tank
2. Fill the tank with fresh water and 1/2 bottle of Wisk or Tide. Also pump a capful or two through the toilet using FRESH water.
3. Leave it alone for a few days, then pump out.

On the first go-around, you might want to repeat steps 2 and 3. After that, pump out often, and after you do, put a few gallons of fresh water and some detergent into the tank. Finally, try to flush only with fresh water instead of letting the toilet draw in whatever raw water the boat is floating in. There's a lot of microscopic plant and animal matter in it that then decomposes in the tank, adding to the stink. I use the flexible shower hose in the head to fill the bowl before flushing.

My .02