Where is that awful smell coming from?

[koliver]

Well....first I thought it might be the boat we were rafting with. Then I though it might be ours.
Then we spent a few days with our grandkids aboard, so..oo, the toilet was used more than normal, by an order of magnitude, and it was definitely originating on our boat. Oh, the weather took a turn towards hot!
Up came the floor boards, It was quickly obvious that the big circular panel on the top of the holding tank had let go, so every time the head was flushed, the odor was forced out into the bilge. Luckily, we were tied to the dock by this time, so the edict "go ashore" could be enforced.
Now what, you might ask.
The tank is below the galley floor, where the hatch opening measures 17x 26 and the depth in the bilge is 24". The tank measures 16x40x12, for a capacity of only 32 g US.
The internet revealed a supplier with a 40 g US tank of appropriate dimensions, which has now been ordered. This also gives me the opportunity to increase the vent size to 1", The supplier will install the 3 fittings where I want them, so I have emailed my drawing, and now await their email to announce readiness.
My mock-up on a piece of graph paper, shows how the new tank will squeeze through the opening with only a few mm of structural enlargement required. of course i am ready to make liberal use of the sawzall in the installation.

To the receipt of the replacement tank, with no flushing till then.

Watch this space.

 

[Comodave]

First, is the supplier Ronko? They make an excellent tank. I would try, try, try to add a second vent out the other side of the boat. It is the best thing you can do to help smells stop. Get oxygen into the tank and the anaerobic bacteria will die, it is the smelly one. The aerobic bacteria will grow, it isn’t the smelly one. Now is the time to have 2 vent fittings spun into the tank.

 

[koliver]

First, is the supplier Ronko? They make an excellent tank. I would try, try, try to add a second vent out the other side of the boat. It is the best thing you can do to help smells stop. Get oxygen into the tank and the anaerobic bacteria will die, it is the smelly one. The aerobic bacteria will grow, it isn’t the smelly one. Now is the time to have 2 vent fittings spun into the tank.

Naturally that is one of the obvious upgrades I will make. The original was a 1/2" vent line that likely had stuff in it more often than not. This one will have a full 1". and if I can find routing that works, will go out both sides of the boat.
And, (thanks Peggie) no filter.

Thanks Dave, I will get a second vent spun in too.

 

[Bacchus]

I agree with Dave that a second vent can work well. I was able to cure a smelly tank that way on my last boat. In order to work well the vents need to be fairly straight and the shorter the better. If that's a problem you might consider adding an additional fitting on top where you can access it after installation. Plug it for now. If you still have odors you can add a bubbler and it will make all the difference in the world.
Details of what I did are written up on my Bacchus website in projects section.
No need to worry about until / unless you still find some odors. With a fitting it's easy to add a dip tube and inexpensive 12V fish tank aerator.

 

[Comodave]

Formula put a vent filter on the holding tank. Where they put it makes it unreachable to change it, maybe that is why it looks original still after 24 years. So I just added 2 1.5” vents, one to each side of the boat. I left the 5/8” vent with the 24 year old filter in place because I could not get to it.

 

[Bacchus]

Dave
Don't you lovewhere dome builders put things!!
My buddies Tiara had a vac u flush burried and they suggested he cut his teak & holly sole to access it... even said they wouls send him some materials. I would have been livid if I spent what he did on a boat a critical system could not be serviced and they put on the owner to DIY or spend big $$$

 

[koliver]

Is your venting done with 1.5" ? I was thinking to go 1", but since the fitting haven't been added to the tank, maybe I should do 1.5" ?

My access remains good. The galley floor hatch may need to be trimmed to angle the longer tank through it, but I did a mock up with graph paper that showed me how long a tank I can stuff down the hole. Once in place, I can access the far end through a hatch in the fore cabin floor. One of the vent lines can go the present route, back into the ER then a right angle and over to the side of the hull, at ceiling level. One side is awkward, so a second line can go from the front of the tank, forward to the anchor locker, up to deck level and out against the aft chain locker bulkhead. That will exit the hull just below the upper teak fender guard.
I just need to get all these little things from the marine store and get started.

 

[Dwk]

Our Mainship came with the toilet bowl on top of the 9+- gallon holding tank that was the first piece of original equipment we replaced. We added a 26 gallon Ronco holding tank,and a Raritan Elegance toilet with the control panel. Ronco added an additional vent to ensure plenty of air circulation within the tank. I was unpleasantly surprise by the odor coming from the old sanitation hoses during replacement. With our new system we have zero odors. It’s amazing the stink that comes from old permeated sanitation hoses!

 

[Comodave]

The OEM vent was 5/8”, way inadequate. I put in 1.5” vents because I had the room and the more air the better. And I used SaniFlex sanitation hose because it is so flexible and doesn’t permeate.

 

[Comodave]

Our Mainship came with the toilet bowl on top of the 9+- gallon holding tank that was the first piece of original equipment we replaced. We added a 26 gallon Ronco holding tank,and a Raritan Elegance toilet with the control panel. Ronco added an additional vent to ensure plenty of air circulation within the tank. I was unpleasantly surprise by the odor coming from the old sanitation hoses during replacement. With our new system we have zero odors. It’s amazing the stink that comes from old permeated sanitation hoses!

Oh the Traveler heads are terrible, the smell comes up out of the tank every time you flush. We had one in a Carver and immediately took it out.

 

[Comodave]

Dave
Don't you lovewhere dome builders put things!!
My buddies Tiara had a vac u flush burried and they suggested he cut his teak & holly sole to access it... even said they wouls send him some materials. I would have been livid if I spent what he did on a boat a critical system could not be serviced and they put on the owner to DIY or spend big $$$

We have a Vacuflush in our Formula. Of course it leaks vacuum…. It will be replaced with a Marine Elegance if I can get a new discharge hose run. Formula did an excellent job of burying the present discharge hose. The vacuum generator is back in the waaay aft end of the engine room where there is absolutely no room to service it. The really nice thing about the ME is that all of the service parts are right there in the head itself. Next winters big job.