Sea toilet hose: fitting

Chiara’s slave

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The clip does not hold the hose on. This thread is about the difficulty of getting the hose on, which is solved by heating it so that the internal bore is enlarged to go over the spigot. As it cools it shrinks and seals itself around the spigot. 10 years later when you come to replace it you will almost certainly have to cut it off the spigot. The clip is there to seal the hose against the spigot so that it does not leak.

The origins of double clipping go back 60 years or more when flexible hoses came in which were nothing like modern hoses and worm drive clips that were nowhere as good as the ones we have now (and rarely made of 316 stainless). Not surprisingly people were sceptical about this arrangement and the mantra of double clipping came in - and still persists today - despite it being completely unnecessary. It persists because there is no R&D to test out new materials and processes unlike in other areas where securing hoses to spigoted tubes is common and critical. Look at marine engines. Nowhere is there double clipping even on pressurized coolant systems. Look under the bonnet of an ICE vehicle and nowhere will you see double clipping, or in many cases even clips as secure as worm drive made in stainless.

Advances come from challenging the status quo and this is an example of the lack of challenge resulting in a practice that no longer relevant. The idea that you should double clip all the hoses on your holding tank is just nonsense. As to evidence the number of unexplained sinkings is tiny and almost certainly none have been caused by a failure to double clip hoses. As to insurers they have no idea whether it is needed or not - I doubt they have ever had a claim resulting from failure because of lack of doubling clipping. They just rely on what surveyors say, and the origin of their "opinion" is exactly as I described above.

One would like to think that manufacturers have tested their clips and ensured that they do not fail, but I guess they are unwilling to share their findings as it would immediately half their sales in this sector of the market.
I’ve got 2 GPS sources. And paper charts. 2VHF radios. I think I don’t need to push innovation for the price of 6 jubilee clips.
 

Chiara’s slave

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Don’t use a screwdriver. Use one of these:
View attachment 158110

I used to use a 1/4 drive 8mm socket and a ratchet but the above is even better in most places. They’re slightly flexible too.
I used a ring spanner, it fitted the space better and I could ‘feel’ it onto the nut better. You can’t see and turn the things at the same time on a Dragonfly, if you’re a normal adult.
 

lustyd

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The second clip has nothing to do with failure of clips. It’s standard in safety planning to take such measures, from air travel to nuclear and all the way down to yachts.
The second clip allows less pressure to be put on each, lowering the risk of cracking the underlying material. It offsets the screw mechanisms ensuring no gaps caused by flat spots. It allows for human error, you might forget to tighten one but statistically much less likely to forget two. Many reasons, almost none are failure of the clip
 

LittleSister

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The second clip has nothing to do with failure of clips. It’s standard in safety planning to take such measures, from air travel to nuclear and all the way down to yachts.
The second clip allows less pressure to be put on each, lowering the risk of cracking the underlying material. It offsets the screw mechanisms ensuring no gaps caused by flat spots. It allows for human error, you might forget to tighten one but statistically much less likely to forget two. Many reasons, almost none are failure of the clip

But a yacht isn't a nuclear power plant, or an airliner carrying hundreds of passengers at a time, and flying hundreds of thousands of miles, often over cities.

Why not three clips? Or four?
 

lustyd

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But a yacht isn't a nuclear power plant, or an airliner carrying hundreds of passengers at a time, and flying hundreds of thousands of miles, often over cities.

Why not three clips? Or four?
No but it is still a safety critical use case and the methods remain the same. A third or fourth doesn’t incrementally improve safety, it’s all based on maths so a second offers an enormous improvement on one but a third only slightly improves the odds.
 

Chiara’s slave

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No but it is still a safety critical use case and the methods remain the same. A third or fourth doesn’t incrementally improve safety, it’s all based on maths so a second offers an enormous improvement on one but a third only slightly improves the odds.
Exactly so. Nuclear power plants might prefer even the incremental increase. We boat owners have to draw the line somewhere. To misqote Monty Python, the count shall be 2.
 

Tranona

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The second clip has nothing to do with failure of clips. It’s standard in safety planning to take such measures, from air travel to nuclear and all the way down to yachts.
The second clip allows less pressure to be put on each, lowering the risk of cracking the underlying material. It offsets the screw mechanisms ensuring no gaps caused by flat spots. It allows for human error, you might forget to tighten one but statistically much less likely to forget two. Many reasons, almost none are failure of the clip
Then can you explain why engines which use hoses to transfer hot coolant under pressure use only one clip?

You are really good at imagining situations that simply do not exist. I don't think you have ever actually attached a hose to a toilet spigot. Can you give a real example of flat spots? or the underlying material cracking? or proof that you need less pressure with 2 clips rather than one? or why an individual would be negligent in tightening one, but not the other?

Can you direct me to a published document that says a toilet pump spigot is a "safety critical item" and having 2 clips is "standard safety planning"?
 

lustyd

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Then can you explain why engines which use hoses to transfer hot coolant under pressure use only one clip?
Yes I can. An engine hose is not critical to the safety of the boat and crew, it would result in a temporary loss of propulsion which can be fixed at leisure through the use of an anchor. Water ingress is a different beast and sane people prefer to avoid it for the cost of a £1 jubilee clip.
Similarly the front door at NATS used standard hinges the last time I was there since it has no impact to safety in the air.
 

jwfrary

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With reference to the Mikalor clamps, these are sold by hydraulics suppliers for one fifth of the 'marine' price and are exactly the same make and spec'.
Yes and no, you have to be a bit careful, some stainless banded clips have steel bolts, and theres 304 clips and 316 clips.

Its a mine field!
 

Velopaul

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I have just replaced the toilet on my boat (Sadler 32) with the hoses and clips as the toilet smell on board was becoming noticeable. The worn pump and tatty seat could have only been replaced as an economy measure but in fact it cost less to do the whole lot and I’m so glad I did. When I removed the access panel behind the loo I found only the outlet pipe had a loop going above sea level (my toilet is completely below sea level unless on a port tack) also without any vent at the top as is now recommended). The inlet pipe went straight from sea cock to pump.
The only way I could get the new hoses onto the sea cocks was by, after cleaning the bronze fittings with wire wool and coating with fairy liquid, heating the ends in a kettle of boiling water for several minutes. I then used a wooden hole plug from the emergency kit to stretch the end of the pipe.
 

Stemar

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Given the trouble I've had getting hoses on and off seacocks, I'm not sure even one clip is necessary but, as a confirmed pessimist, I fit them and check them as part of routine maintenance. I'm with Tranona, I reckon one good one is better and more secure than two pound shop specials (also sold in bad chandleries), but if my insurer wanted two, well, grumble, grumble, OK then.
 

dansaskip

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Agree with others Butyl pipe is better never mind the expense. A bit of lube helps too. Makes me smile all this 1 clip or 2. Given the difficulty of removing a hose I can't see one coming detached all on its own. Anyway even if it did no matter because I always shut my seacocks - both inlet and outlet, unless I am actually pumping. Don't tell me all you experienced and trusty mariners leave your open. Do you? Poor practise in my humble option.
 

Chiara’s slave

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Agree with others Butyl pipe is better never mind the expense. A bit of lube helps too. Makes me smile all this 1 clip or 2. Given the difficulty of removing a hose I can't see one coming detached all on its own. Anyway even if it did no matter because I always shut my seacocks - both inlet and outlet, unless I am actually pumping. Don't tell me all you experienced and trusty mariners leave your open. Do you? Poor practise in my humble option.
And no excuse for it if you have a holding tank. It only needs to be open for over side discharge once in a blue moon.
 

Tranona

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Don't tell me all you experienced and trusty mariners leave your open. Do you? Poor practise in my humble option.
Why? The whole thrust of the argument about clipping is that there is no credible evidence that hoses becoming detached is a cause of sinking, nor that 2 clips are "safer" than 1 so it is irrelevant whether the seacocks are left open or not. Many older boats have underwater cockpit drains with seacocks. How many owners close those? Why should the other seacocks like the toilet ones be any different?
 

john_morris_uk

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Agree with others Butyl pipe is better never mind the expense. A bit of lube helps too. Makes me smile all this 1 clip or 2. Given the difficulty of removing a hose I can't see one coming detached all on its own. Anyway even if it did no matter because I always shut my seacocks - both inlet and outlet, unless I am actually pumping. Don't tell me all you experienced and trusty mariners leave your open. Do you? Poor practise in my humble option.
Are you really suggesting that I crawl under the companionway steps and stretch into the under sink locker to open and close our galley sink drain seacock every time I use the galley?

Last count we have over a dozen seacocks and most of them stay open all the time.

They’re available to be closed if there’s a need.
 
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