[QUOTE=tim_farrell;8748] ...marine head has waste coming back into the bowl after a flush. I noticed, through the porthole, last night that waste was actually coming out of the station vent. I assume this means my holding tank is full....

Thanks in advance.[/QUOTE]

Your assumption is correct. When the tank is full and you try to pump / flush more material, it can either go out the vent.... or if that is blocked, the back pressure will cause it to flow back to the bowl. You need a pumpout, but first make sure your vent line is free of obstruction.

We have even noted that the settee over the holding tank will bulge up (yes, it will lift a person sitting there) when the tank is full and the toilet is pumped.

Tim, the useful volume of the Mk II holding tank is only 14 gallons. It is surprisingly easy for a couple or a small family to fill that space in just two or three days.

One space saving trick I use when the bowl needs to be flushed is to use the hand shower head of the sink to do the rinsing. A 'targeted' spray can clean the bowl with less overall water volumn than the pump can.

Of course, I don't need to remind anyone (I hope) that NOTHING that hasn't been eaten should go into the holding tank. All waste paper goes into a plastic bag in the waste basket. Then we use a handy wipe to wash our hands, and then that is laid over the waste level in the basket.

More on this on other threads...do a search if interested.

If you can access the holding tank, just tap the side. You should be able to tell where the liquid level is at.
We have a level monitor on our water and waste tanks, but the calibration for the full waste level does not want to work yet - something to play with. Luckily, we head offshore every couple of trips, so dump the tank before we return to shore. Only problem we have, is when the wave pump water into the tank, and the displaced air is blown out the breather, not a great smell :)

I must say, Catalina got it right with gravity discharge of the waste tank.

Tim,

I discovered this handy feature on my boat shortly after purchasing it. With the port open in the head effluent would be ejected out the vent, hit my wisker pole and slash in my face. I too could not understand the broker delivering my boat with a full holding tank.

Some time later trying to understand the high output of my crews bladders, I dicovered my y valve was sealing and filling my holding tank with salt water on starboard tack. I had noted during haul out the through hull for the overboard discharge dripped for several days on the hard. It was seaping waste out and when in the water was seaping salt water in.

I still am impressed with Gerry Douglas's foresite in designing this impressive holding tank full alert system.

Even with my crews impressive consumption of beverage, my holding tank has a much better range since stoping the salt water input.

By the by I switched my head to fresh water flush and even when I do get a spritz from the vent it does not taste as salty as it used to.

Tim - we have also experienced the fountain of Icky stuff!:( With just my wife and I aboard we try to pump out every five days - MAX! We are on the Great Lakes so pumping out is our only option. As Steve noted - you must be careful when to "Not have the head port open" - (Day 5 for me). I guess that really is a closed loop if you think about it. Immediate notification of a tank full situation.
But - the overflow can clog your vent and create more issues. I am replacing all sanitation hoses this year and will be replacing the vent hose and cleaning the stanchion out.

Anyway - Has anyone relocated the vent to a more friendly location? Or maybe installed a diverter?
I purchased a tank monitor (external sensors) over the winter and discovered that the tank is built in and surrounded by fiberglass and wood. Any ideas on cutting the tank mount to accommodate the sensors.

As you pump the tank and cause a vacuum, hold a hose with water comming out of it against the vent to flush any gunk our of the vent pipe. Then listen for a whistling which will mean the vent is clear.
John Meyer
Hilbre 2135

Or you could try this one "CALL THE PUMP OUT LAUNCH ",:eek: and yes I have seen my settee swell up like a ballon when it is filled.

[QUOTE=hilbre;8787]As you pump the tank and cause a vacuum, hold a hose with water comming out of it against the vent to flush any gunk our of the vent pipe. Then listen for a whistling which will mean the vent is clear.
John Meyer
Hilbre 2135[/QUOTE]

Does anyone know why the Catalina 36 was designed with the waste tank vent in the stanchion?? All my previous sailboats had the waste tank vent out the side of the boat. Waste tank odors are heavier than air. Coming a side vent on the boat I never had odors arrive in the cockpit. The vent out the stanchion the odors flow over the deck and get directed toward the cockpit.

The full tank sneaks up quick. I pumped out last weekend, spent the weekend on the boat, and went to pump out again yesterday. About a third of a tank! And I know mine does not backfill.

The reason I had to pump out again was that I changed the macerator pump out. Not fun! But we are leaving for 2 weeks on saturday and pump out stations are few and far between north of Vancouver so it didn't seem optional. I have had crew sprayed by that stupid stanchion vent twice while we've had this boat and plan to change to a vent out the side of the hull probably before the summer is over.

Only problem I see is that it's way more work than just buying a vent fitting off the shelf at West Marine and sticking it through the side of the boat? Having it come out the stanchion still leaves you prone to spraying the toerail and a few inches of deck.

Only if someone is on the leeward side siling by when THERE SHE BLOWS !!!!:)

Drilling a hole on the outside of the stanchion would further weaken it in an already compromised area.

[QUOTE=tim_farrell;8887]I'll also be calling the pump out boat each weekend whether I need it or not - just to keep the tank relatively empty.

Thanks again for all your help![/QUOTE]

Are using the toilet for solids and liquids (poo & wees)?
When we had a small porta pottie, we used a bucket for the boys #1's.
This extended the time between the need to empty.

How big is your holding tank?
Does your shower discharge overboard or into the holding tank.

We can do several days with 5 adults on board, but always empty before it gets too full.