HOSE CLIP FAILURE

TQA

Super Anarchist
1,208
35
Caribbean
11 Years ago my boat was the subject of a no expense spared major refit. All hoses and hose clips were replaced. A substantial supply of spare clips formed part of the inventory when I bought her. 

In the past 5 years 1 to 3 clips have failed each year. Not because they were over tightened or seized they just broke in silence and secretly.

This morning I came across another.

So all clips and most hoses are getting replaced.

Does anyone have a particular make or type of clip that is to be recommended. 

If you have any hose clips of the type MURRAY made in the USA I would replace them with another make. 
 

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IStream

Super Anarchist
10,784
2,970
Yeah, those aren't the best for marine use. The screw is mild steel and the perforations lower the strength significantly. A better choice is AWAB or Scandvik, which are 316 stainless and non-perforated. They're sold by Defender, Jamestown Distributors, and the other usual suspects. For very critical jobs like clamping raw water hoses, I'd go with a T-bolt style. 

 

Moonduster

Super Anarchist
4,823
229
It's extremely difficult to find Stainless-Screw/Stainless-Band hose clamps. Additionally, the style you've shown aren't really very good - they tend to cut the hose and they tend to break at the obvious weak points as yours have.

I would avoid any chandlery product where the outlet can't provide sourcing information indicating the clamp is stainless/stainless and 304, 318 or, preferably, 316. Check with a magnet to be sure.

For good results, look here and here.

 
Agree with the above. I won't have a perforated clamp on my boat - because they are so good at failing as you have discovered. 

In our part of the world, Budget stock 'JCS' brand I believe, and I have found them to be of decent quality. A little dab of grease or Tefgel on the worm grooves helps prevent galling too.

The T-bolt style that IStream mentions don't seem to come in sizes under about 1 3/4", but are more often used on smaller boats for exhaust hoses and maybe cockpit drains.

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For critical, boat-sinky stuff, use two clamps with the screws rotated 90 degrees apart. Many people will say 180 degrees - but they're wrong.

 
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Coolerking

Member
436
38
LBC
The only way the perforated clamps fail like that is if they get wet with seawater and never rinsed off.

They are not to be used on wire reinforced hose.

AWAB or ABA are solid band clamps, take much more force to tighten up correctly,  are pretty much bulletproof if kept clean.

They cost 3x what the cheap ones do. 

Use two on any hoses below water line.

 
Fair question. It's because of their tendency to tighten in an oval shape due to the rigid worm housing. More noticeable on smaller diameters - tighten a new one in open air (rather than around a hose, I mean) or around a rigid fitting or tube and you will observe the effect. A 90 degree offset distributes the clamping force more evenly than 180 degrees.

Feel free to disagree or ignore!

I see Mr. Mainesail has a page on the subject - though he illustrates the sub-par 180 degree methodhttps://marinehowto.com/proper-installation-of-double-hose-clamps/

Biggest issue - other than the availability of poor quality camps that may be unwittingly selected by the uninformed -  is that a lot of fittings don't have the space available to mount two clips properly - with the bands on the correct side of all the barbs. Another thing to keep in mind is that a good quality clip with a good quality wrist tightening it can deform some polymer (e.g. Marelon) fittings if too much 'enthusiasm' is applied.

 
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IStream

Super Anarchist
10,784
2,970
Ah, the classic hit and run.

Show me the data on spring clamp performance after chronic saltwater exposure.

 
Ok, I am currently working for a highway maintenance contractor. Road brine is normally around 24 % salt. The truck has a fair bit of plumbing, the best being held together with tee bolt stainless clamps, but the key is replacement, nothing lasts more than a season. Surprisingly, the spring clamps seem to last the longest. Your results may vary.

 
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