Smelly heads

[West Coast]

Congratulations! There have been many threads on this subject but that's the best advice I've read yet. Give it a pump, it stinks a bit, for all of five minutes, and then its gone.

Even quicker, give it a pump then light a match, gone straight away! Good trick for getting rid of smells, whatever the source!

 

[john_morris_uk]

I read that. Whilst I would not dream of saying what happens on other boats, we have one heads that has NEVER had ANYTHING solid passing through it. If we leave the boat for a week, I need to flush through copiously to get rid of the bad egg smell. This does vary dependent upon the time of year and ambient temperatures. I know that on our boat the smell emanates from the inlet pipe - nothing to do with our sewage of the outlet side.

But it is to do with the way the pump allows a tiny bit of the 'pump out' mixture to get into the 'pump in' supposedly fresh (sea) water. The pumps just aren't very good at completely sealing in from out and hence the back contamination.

Stale seawater by itself doesn't 'go off' and smell. There have been several people who have experimented and shown this to be true. From what you and Nigel are saying, it appears that it doesn't need solids but only the tiniest bit of urine to be in the seawater for the bugs to start growing and making hydrogen sulphide.

Otherwise why does LOTS and LOTS of pumping before you leave the boat ensure that the smell doesn't occur. The answer is that despite the slightly leaky pump, you've flushed enough fresh (sea) water through the system to thoroughly purge any urine (or solids in other peoples's boats) that have leaked back past the 'O' ring in the pump into the inlet pipe.

 

[JumbleDuck]

I read that. Whilst I would not dream of saying what happens on other boats, we have one heads that has NEVER had ANYTHING solid passing through it. If we leave the boat for a week, I need to flush through copiously to get rid of the bad egg smell. This does vary dependent upon the time of year and ambient temperatures. I know that on our boat the smell emanates from the inlet pipe - nothing to do with our sewage of the outlet side.

The solid material (how polite we are being) doesn't have to come from the toilet that's smelling. Just a few blobs sucked in from the Number Two Heads would be enough.

 

[Vanilla]

I read that. Whilst I would not dream of saying what happens on other boats, we have one heads that has NEVER had ANYTHING solid passing through it. If we leave the boat for a week, I need to flush through copiously to get rid of the bad egg smell. This does vary dependent upon the time of year and ambient temperatures. I know that on our boat the smell emanates from the inlet pipe - nothing to do with our sewage of the outlet side.

+1. It happens only happens now and again on my boat, and I'm convinced each time it's due to a bit of seaweed being sucked into the inlet unseen and decomposing while I'm away from the boat. The last time it happened the stink stayed for weeks, though of course only on first flush, but went immediately after my lift and pressure wash when I forgot to close the sea cocks...I think the pressure wash blasted the seaweed out!

 

[Mistroma]

Even quicker, give it a pump then light a match, gone straight away! Good trick for getting rid of smells, whatever the source!

Good tip, I believe that YM demonstrated this one a while back with the last trip out on their test boat (last ever ). Pretty certain that the funny gas smell did disappear.

 

[dslittle]

The solid material (how polite we are being) doesn't have to come from the toilet that's smelling. Just a few blobs sucked in from the Number Two Heads would be enough.

I suppose that might happen in the Horse Lattitudes but I sincerely hope that nothing hangs around the boat for over a week when I leave it!!!

 

[alahol2]

But it is to do with the way the pump allows a tiny bit of the 'pump out' mixture to get into the 'pump in' supposedly fresh (sea) water. The pumps just aren't very good at completely sealing in from out and hence the back contamination.

Stale seawater by itself doesn't 'go off' and smell. There have been several people who have experimented and shown this to be true. From what you and Nigel are saying, it appears that it doesn't need solids but only the tiniest bit of urine to be in the seawater for the bugs to start growing and making hydrogen sulphide.

Otherwise why does LOTS and LOTS of pumping before you leave the boat ensure that the smell doesn't occur. The answer is that despite the slightly leaky pump, you've flushed enough fresh (sea) water through the system to thoroughly purge any urine (or solids in other peoples's boats) that have leaked back past the 'O' ring in the pump into the inlet pipe.

That doesn't explain why it happens in a Lavac where there is no internal route from outlet to inlet.
If I remember to pump the Lavac, on entering the boat and before lifting the lid, I can virtually eliminate the problem. Unfortunately I very rarely remember.

 

[john_morris_uk]

That doesn't explain why it happens in a Lavac where there is no internal route from outlet to inlet.
If I remember to pump the Lavac, on entering the boat and before lifting the lid, I can virtually eliminate the problem. Unfortunately I very rarely remember.

The only time I've had smell problems with a Lavac was when the inlet and outlet through-hulls weren't separated very far. Unless the boat is moving or in a tideway with a fair amount of water moving past the boat its easy to see how a tiny amount of what you flush out can get sucked back in. The way most Lavac's are plumbed (correctly done with big loops up above the waterline) you have to pump for ages to get the thing flushed through really well. In still water I've sometimes seen a cloud of detritus round the side of the boat where one has flushed. Its not hard to see that some of it is getting back into the inlet.

 

[davidwf]

I fitted one of these http://www.seasmartmarine.co.uk/ a year ago it works really well. Its main advantage is that it treats the water near the sea cock and works out if the toilets being used a lot in which case it stops dosing until its not been used for a bit.

 

[maby]

I fitted one of these http://www.seasmartmarine.co.uk/ a year ago it works really well. Its main advantage is that it treats the water near the sea cock and works out if the toilets being used a lot in which case it stops dosing until its not been used for a bit.

Interesting - I've been thinking of installing one of those - good to hear the recommendation

 

[davidwf]

Interesting - I've been thinking of installing one of those - good to hear the recommendation

If you do I'd recommend changing the inlet hose at the same time to allow it to have a clean start, also new hose is a lot easier to get onto the spigot of the connector.

 

[maby]

If you do I'd recommend changing the inlet hose at the same time to allow it to have a clean start, also new hose is a lot easier to get onto the spigot of the connector.

The boat is only a year old, so I'm hoping that the hose is still in decent condition! It would be a real pain to change, so I'm not rushing to do it unnecessarily.

 

[Amulet]

Mine pong even at the start of the season after a week in the water and having been unused since they were dry for the winter. I have been lead to believe that microorganisms in the east coast mud cause the problem.

I usually adopt the clean an pump on arrival method. However I did have a phase of chucking a bucket of fresh water in the pan on leaving the boat, and it did seem to work. I'm usually too lazy however.