Oh SH!!!!!T, why did that happen?????!!!

markc

markc

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I have a Jabsco diaphragm pump for emptying the holding tank at sea. I replaced a similar pump about 5 years ago, and it's worked fine... UNTIL NOW!! at some point during the last emptying session, the clamp ring around the pump sheared, pumping copious amounts of brown soup into the bilges. The smell alerted us to a problem, but by then, it was all too late :sick:I cannot express how vile this was, and what an awful job it was cleaning it all out 🤮🤮🤮🤮🤮🤮.

This now poses the question, how can I prevent this happening again? It seems that a diaphragm pump is the preferred choice for the application, but both Whale and Jabsco offer replacement clamping rings, so I suspect they are known to fail. I really don't want to repeat the experience, and considering that the pump is used at sea, with the engines running, it's impossible to notice a problem before it's too late. Any suggestions??

1752137257162.png
 
Originally had a Sealand on the boat, had to dismantle and repair the thing a few times,when it finally ground to halt (literally) gearbox seized ,purchased a Whale Gulper and its been doing the job OK.
The pipes of course were of different ODs and one of course one poo pipe was about an inch too short and...............
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I had a similar experience many years ago. If possible fill the bilges etc with water from a hose pipe and loads and loads of bleach/bathroom cleaner and leave it overnight. It will kill any nasties and probably better the boat smells vaguely of pine or lemon for a few days instead of an imagined brown soup smell.

As to the clamp ring failing that is very unlucky. Lots of reasons why it could have failed from overtightening at some point, incorrect bolts/screws to just a poor plastic moulding.

You can buy stainless steel jubilee clamps with an internal lip. If you can find one the right size, cut off the plastic screw bosses on the existing clamp ring and put a lipped jubilee over it. It won't come off again.
Something a bit like this. There are also chimney pipe clamps - similar idea.

Univee Ring Clamps
 
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As Kashurst said, get the hose in with lots of bilge cleaner and bleach, replace the pump with a sealand one, pretty bullet proof, all spares available reasonably priced, only thing if you pump out with the seacock closed, it turns the duck bill inside out, so good idea to carry spares, mines 13 years old and that's the only problem i have had , self inflicted 😡
 
kashurst said:
I had a similar experience many years ago. If possible fill the bilges etc with water from a hose pipe and loads and loads of bleach/bathroom cleaner and leave it overnight. It will kill any nasties and probably better the boat smells vaguely of pine or lemon for a few days instead of an imagined brown soup smell.

As to the clamp ring failing that is very unlucky. Lots of reasons why it could have failed from overtightening at some point, incorrect bolts/screws to just a poor plastic moulding.

You can buy stainless steel jubilee clamps with an internal lip. If you can find one the right size, cut off the plastic screw bosses on the existing clamp ring and put a lipped jubilee over it. It won't come off again.
Something a bit like this. There are also chimney pipe clamps - similar idea.

Univee Ring Clamps
Click to expand...
Yes, I immediately got a hose in there and flushed the whole lot out, then used the wet vac to get the last bit of water then sprayed the bilges liberally with a pet odour remover spray. It was just very unpleasant. Plan is to avoid it next time - I like the suggestion of a jubilee clip over the existing plastic clamp. Another option perhaps is if I can get one of these the correct size to replace the plastic clamp

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Hurricane said:
I've had those clamps fail in the past.
I think I have some spares.
I might bring them back and make some stronger 3D printed alternatives.
They don't have to look pretty - just functional.
Click to expand...
Not sure I'd entrust this to my 3D printer... I have a feeling (may be incorrect) that the layer lines in whichever print orientation, are a potential weakness.... this feels like a job for metal
 
markc said:
Not sure I'd entrust this to my 3D printer... I have a feeling (may be incorrect) that the layer lines in whichever print orientation, are a potential weakness.... this feels like a job for metal
Click to expand...
Still think it is worth a try - I'm doing a lot with ABS and ASA which is strong enough for most jobs.
I could also thicken up the cross section of the clamping rings.

Actually, my pump only serves the crews cabin which we only use for storage so I can experiment without causing us any "down time"
 
Hurricane said:
Still think it is worth a try - I'm doing a lot with ABS and ASA which is strong enough for most jobs.
I could also thicken up the cross section of the clamping rings.

Actually, my pump only serves the crews cabin which we only use for storage so I can experiment without causing us any "down time"
Click to expand...
If my pump moved water rather than waste, I'd roll the dice, but....
 
On a Sealine S28, the holding tank is mounted quite high up relative to the pump, and the hose is routed in such a way that you can't easily lift it above the waste level of the tank if disconnected.
So if you need to maintain the pump ...

It was possibly one of the worst jobs I have EVER had to do.
Mrs SC35 wouldn't touch me with a boathook for a week.
 
SC35 said:
On a Sealine S28, the holding tank is mounted quite high up relative to the pump, and the hose is routed in such a way that you can't easily lift it above the waste level of the tank if disconnected.
So if you need to maintain the pump ...

It was possibly one of the worst jobs I have EVER had to do.
Mrs SC35 wouldn't touch me with a bargepole for a week.
Click to expand...
When I replaced the pump I added an isolation valve each side of the pump so it would be much easier to do planned maintenance. Obvs didn't help me preventing this incident!
 
markc said:
When I replaced the pump I added an isolation valve each side of the pump so it would be much easier to do planned maintenance. Obvs didn't help me preventing this incident!
Click to expand...
Why didn't Sealine put that in at the Factory?
Of course the waste tank was full when it all went wrong ... wet wipes were the culprit.
Advice and guidance was provided on why it would be a really good idea not to do that again.
 
SC35 said:
Why didn't Sealine put that in at the Factory?
Of course the waste tank was full when it all went wrong ... wet wipes were the culprit.
Advice and guidance was provided on why it would be a really good idea not to do that again.
Click to expand...
What were wet wipes doing on the boat in the first place? 🤷🏽
 
Portofino said:
Move over to an impeller ( with a blade ) pump .



Jabsco 18590-2092 Macerator Pump, Self Priming, Run Dry Protection, Waste Evacuation, 12 Volts DC : Jabsco: Amazon.co.uk: Business, Industry & Science

12V SURGEFLO MARINE MACERATOR BOAT PUMP TO EMPTY YOUR HOLDING TANK | eBay UK

Failure mode is they just jam , they don’t burst or anything like that ,
It’s easy to replace the impeller sold in every marina shop €10 .Or carry a spare .
Click to expand...
Well, everything is pre-macerated and all that I have read points to a diaphragm pump as being the most reliable and effective type of pump for emptying the holding tank, not withstanding the obvious weak point I raised! In normal operation the pump is quiet, self priming, not prone to blockages.... I just want to prevent it splitting in two!
 
Close the facilities permanently. I’ve gone for premium……with lids. Mrs Markc will be agreeable with this given we’ve gone top draw bucket wise I’m sure

IMG_2838.jpeg
 
markc said:
Well, everything is pre-macerated and all that I have read points to a diaphragm pump as being the most reliable and effective type of pump for emptying the holding tank, not withstanding the obvious weak point I raised! In normal operation the pump is quiet, self priming, not prone to blockages.... I just want to prevent it splitting in two!
Click to expand...
Sure . Same on my boat . Macerated by the heads as well .Therefore all the more reason to go impeller .
I think once in 9 yrs I opened the pump up . Out of curiosity ( no fault ) and maintenance wise popped in a new impeller .

You asked for a solution. I have given one , “ horse to water “ springs to kind .

If you continue with what you have with a beefed up / bodged flange = there will be third 8hit show .
 
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