Flushing with fresh water

[rwidman]

Originally Posted by drew23

........I've removed the through-hull near the head and glassed over the hole, ...........

I hope you did this the proper way, by grinding out the area to a large enough diameter for a good fiberglass bond, not just plugging the hole with fiberglass. Otherwise, you may have a bigger problem than sanitation hoses.

As for the rest of it, read and heed what Peggie writes. She is the expert. The short version is, you cannot safely use a head designed for raw water connected to your potable water system. You or your guests could get very, very sick.

I'll give you one option that I don't think was mentioned: Install a separate water tank for flushing the head. It has to have a dedicated deck fill and no connection to your potable water system.

Me, I would have left things as they were. Seawater is free and unlimited.

[senormechanico]

Originally Posted by rwidman

Seawater is free and unlimited.

Agreed. Besides, if everybody was using seawater it would keep the ocean level from rising.

[farotherside]

Originally Posted by rwidman

I hope you did this the proper way, by grinding out the area to a large enough diameter for a good fiberglass bond, not just plugging the hole with fiberglass. Otherwise, you may have a bigger problem than sanitation hoses.

ground out the 3/4" hole to about 5" slowly sloping outwards. West System 404 high-density adhesive filler to a wood plug matching the core of the hull, glued in place. 4" and 2" patches of biaxial fiberglass patched on, then ground smooth, and West System 407 filler (cut with some cabosil) to fair the patch.

It has to have a dedicated deck fill and no connection to your potable water system.

deck fill? who uses those? dock people, that's who. :P my tanks only ever see water from my own watermaker...

[ericoh88]

Wow!

Long list of answers to a simple question.

A friend from down under had 3 way valve added to the sea water intake and fresh water. On the crossing from Darwin to Indonesia, he changed from fresh water back to sea water and he did not fully turn the 3 way valve. This means all the 3 hoses were all mixing up.

Upon arriving in Indonesia, he felt his fresh water tasted a bit funny. Had to do major cleaning up on the house tank lol.

My 2 cents worth.

I replaced the manual pump with a Jabsco electric pump.

Scenario 1: Use the shower sump water.

Result: After a while, the shampoo water smells and the toilet bowl smells. Don't like the shower water sitting below the grating anyway.

Scenario 2: Use the sink water.

Result: Had to flush the toilet each I use the sink to wash or the sink will fill up with water. Too much work.


Scenario 3: Replace the sea water with fresh water with a one way valve to fresh water high pressure side.

Result: Flooded the bowl. Problem was high pressure fresh water.

Scenario 4: Plumb to low pressure with a one way valve.

Result: Suck water from toilet bowl back to the high pressure side . I discover this when my clear water filter housing is having strange looking things floating inside. That was more than 2 years ago and no, I did not report the "incident" to the Admiral.

Tried with 2 one way valve. They are all useless!

Current set up:

House water tank -> high pressure pump -> a valve (to control amount of water) -> solenoid valve connected to the same toilet switch -> anti siphon -> toilet bowl.

This method seems to work well because the solenoid will open the water supply when flushing out the bowl. Tried without the valve, there was way too much water rushing into the bowl. The anti-siphon allows air to fill the hose without vacuum to strain the toilet pump.

In future, I might want to put in a 3 way valve to connect back the sea water supply.

Good luck in you project.

[Bill4]

What we do day to day:

Flush well with seawater (approx 20 pumps for 1.3 metre outlet hose).

What we do when leaving the boat for a week or more:

Flush with a pan full of fresh water from the shower head. If we don't do this we get a sulphur smell when we next flush. Flushing with fresh water completely stops the smell.

Simple. Why make things unnecessarily complicated?