Double stainless clamps on all hoses?

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HeadedToTexas

HeadedToTexas

Guru
Joined
Jul 3, 2016
Messages
1,439
Location
USA
Vessel Name
Escape
Vessel Make
Mariner 37
Many raw water hose connections on Escape have double stainless steel hose clamps securing hoses to fittings, but not all of them. Do you guys have double clamps on all raw water connections at or below the waterline?
 

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Three rules regarding double clamps on all raw water hoses below the water line including all wet exhaust holes.

Rule #1: ALWAYS DOUBLE CLAMP ALL RAW WATER HOSES!

Rule #2: Any questions arise as to whether or not to double clamp raw water hoses below the waterline, refer to rule #1.

Rule #3: if after reading rule number two there remains any question whether or not to double clamp raw water hoses below the waterline, refer to rule #2.

Putting aside my smart ass comments above, it’s always a very good idea to double clamp hoses. If there’s not enough room to double clamp with half inch hose clamps, use narrower hose clamps and double clamp. don’t go cheap. It’s the most inexpensive insurance one can purchase. More often than not I’ve seen clamps fail. If there’s crevice corrosion, rust ( not stainless), a deteriorating screw, band cracks or any other untold failure mechanism of a clamp, there’s a secondary clamp securing the hose. Remember, while the hose may be tight even when the clamp may have “let go” ,nothing vibrates tight over time.
 
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On every boat I’ve ever owned there’s double ss 90 degree rotated from each other on all through hulls near or under the waterline. Also on all hose connections after anti siphon valves on discharge side of outputs.and all connections on raw water intake side. Cheap insurance. This includes discharges (sinks, sump pumps, AC etc.) as well not just raw water intakes as those can sink your boat as well. . We also use a nut driver not a screw driver to tighten them. With a screw driver you can think they’re tight when they’re not. There’s a wide variance in the quality of these clamps so avoid the cheap ones.
 
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cks said:
Three rules regarding double clamps on all raw water hoses below the water line including all wet exhaust holes.

Rule #1: ALWAYS DOUBLE CLAMP ALL RAW WATER HOSES!

Rule #2: Any questions arise as to whether or not to double clamp raw water hoses below the waterline, refer to rule #1.

Rule #3: if after reading rule number two there remains any question whether or not to double clamp raw water hoses below the waterline, refer to rule #2.
Click to expand...

Hehe, those rules make a ton of sense. Definitely cheap insurance. The previous owner even had an assortment box of 316 stainless clamps! This feels like a two day project to me. Thanks for the reality check, guys.
 
With all due respect guys, I would prefer to have a single quality clamp with no perforations than two perforated clamps. Of course I would prefer two quality clamps if there is room. That is ABYC's position.

David
 
Hippocampus said:
On every boat I’ve ever owned there’s double ss 90 degree rotated from each other on all through hulls near or under the waterline. Also on all hose connections after anti siphon valves on discharge side of outputs.and all connections on raw water intake side. Cheap insurance. This includes discharges (sinks, sump pumps, AC etc.) as well not just raw water intakes as those can sink your boat as well. . We also use a nut driver not a screw driver to tighten them. With a screw driver you can think they’re tight when they’re not. There’s a wide variance in the quality of these clamps so avoid the cheap ones.
Click to expand...

I have mine opposite side or 180 from each other, otherwise totally agree.
 
I use AWAB or ABA clamps. They are all 316 S/S and do not have screw slots. They also have rolled egges so they don’t cut into the hoses. Always double clamp unless the hose barb is too short to fit 2 clamps. I have a flexible driver to tighten them, it will bend to get at the clamp screw.
 
David and Dave are absolutely right on a very important point IMO. Clamps are NOT the place to get lazy or cheap out.
Here's a link to one of CMS articles with more details and good pics for illustration.
https://marinehowto.com/proper-installation-of-double-hose-clamps/

While I am a believer, I can't swear to being 100% in compliance so I honestly need to add a careful survey of all of mine to the top of the spring project list.
DavidM said:
With all due respect guys, I would prefer to have a single quality clamp with no perforations than two perforated clamps. Of course I would prefer two quality clamps if there is room. That is ABYC's position.

David
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Comodave said:
I use AWAB or ABA clamps. They are all 316 S/S and do not have screw slots. They also have rolled egges so they don’t cut into the hoses. Always double clamp unless the hose barb is too short to fit 2 clamps. I have a flexible driver to tighten them, it will bend to get at the clamp screw.
Click to expand...
 
If your surveyor fails to call out missing double clamps then you know you need a different surveyor.
 
Norma clamps are a good one as well if after skinny, non perforated type.
All pretty blood expensive over here especially getting up into the 3 inch plus sizes.

The Tridon T Bolt style has been the clamp of choice for many over here but they are wide and I have had several break over the years, always at the 3 pissy little spot welds.
Ridiculously over engineered with a 10mm s/s bolt but weak as piss where it counts

I now use considerably cheaper yum cha knockoffs - 4 welds vs 3 and narrower so I can double up.
Bolt is not S/S but I have had no sign of rust or failure after 3 years and at the pricepoint, cheap enough to keep a large collection on hand
 
For T bolt clamps that are not welded I use AWAB. They are pricey but are absolutely awesome. I put them on my exhaust hose coming off the engines. They were about $25 each but are really robust and have no welds.
 

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tiltrider1 said:
If your surveyor fails to call out missing double clamps then you know you need a different surveyor.
Click to expand...


Maybe
Maybe not
Unless things have changed or this guy has it completely wrong?

Hose Clamps, Surveyors, and the ABYC
Does the American Boat and Yacht Council require double hose clamps?

By Ed Sherman
I recently received a common question:

I just had a boat surveyed that I am thinking of buying. The surveyor made a big deal out of the fact that the sea cocks on the boat did not have double hose clamps. He cited both USCG regulations and ABYC Standards as requiring double clamps. Is this the straight story?

This is an unfortunate misunderstanding in the industry. The truth is neither the US Coast Guard nor the ABYC require double clamps. In fact, the USCG under title 33, which covers recreational boats, does not even discuss thru-hull fittings, meaning they have absolutely no requirements in this area.

However, boats built in Europe will have double clamps because the ISO Standard that addresses such issues requires them.

As for the ABYC position, I can tell you that its regulation H-27 Standard, Sea Cocks, Thru- Hull Fittings and Drain Plugs, is tried and true. The single clamp requirement has never created any problems in the field—as long as proper, all stainless steel clamps are used. There have been cases where the use of automotive grade stainless band, cadmium plated screw mechanism clamps has caused problems. H-27 is quite specific in requiring clamps made entirely of a stainless steel that is 300 series grade or better.

The thing you need to be concerned with in this case is that the surveyor has made a very basic error, which to my mind opens up the door to questioning his or her overall competency. My advice is to get another surveyor to check out your new boat.

https://www.boats.com/how-to/hose-clamps-surveyors-and-the-abyc/
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Here is my collection of old clamps I changed. Tedious work but it gets you to look in areas that aren’t that obvious and to know where all your through hulls and hoses are, their condition and how to get to them.
 
cks said:
Putting aside my smart ass comments above, it’s always a very good idea to double clamp hoses. If there’s not enough room to double clamp with half inch hose clamps, use narrower hose clamps and double clamp. don’t go cheap. It’s the most inexpensive insurance one can purchase. More often than not I’ve seen clamps fail. If there’s crevice corrosion, rust ( not stainless), a deteriorating screw, band cracks or any other untold failure mechanism of a clamp, there’s a secondary clamp securing the hose. Remember, while the hose may be tight even when the clamp may have “let go” ,nothing vibrates tight over time.
Click to expand...

Makes sense for clamps that need to routinely removed but for those semipermanent uses, why not use industrial rated clamping? Two wraps of 316 3/8" Band-it will NEVER come off. I've seen it tight enough to slice through non-steel reinforced hoses.

Even for critical areas that do need the odd removal they can be secured so that its is quite easy.
 
PaulGel said:
Here is my collection of old clamps I changed. Tedious work but it gets you to look in areas that aren’t that obvious and to know where all your through hulls and hoses are, their condition and how to get to them.
Click to expand...

Another arguement for Band-its. One roll of tape and a box of buckles will do every size from 3x the tape width up.
 
SS clamps from an auto supply are never suitable for below the waterline , regardless of the number used.
 
I have the high quality SS clamps on all below the waterline hoses. And double clamped with the clamps reversed.
 
Like bonding of all underwater metals...even the experts don't totally agree on this subject of clamps and whether doubles are always a must....


So to be comfortable, adequate investigation beyond just a source or two is warranted.


Think how often the question is posted..... "how do I get my hose off the seacock? Cut it off or use some special tool? And there is worry about the right clamp applied properly?
 
"Cut it off or use some special tool?"

Yes there is a special tool to remove hoses that may be reused,


http//www.harborfreight.com/pick-and-hook-set-7-pc-69592.html?cid=paid_google|||69592&utm_source=google&utm_medium=cpc&utm_campaign=&utm_content=&gclid=EAIaIQobChMInIb6-8yM8AIVibKGCh2WZgDDEAQYAiABEgKe_vD_BwE
 
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mention in this thread of quality and number but no mention of torque value of installed clamp.
 
tiltrider1 said:
If your surveyor fails to call out missing double clamps then you know you need a different surveyor.
Click to expand...

Not quite. Fuel fill and exhaust hoses are the only hoses required to be to be double clamped. ABYC recommendation and federal Regulation. Other hoses can be double clamped provided the hose barb is long enough. Double clamping on a too short hose barb can damage the hose.
 
Tightening hose clamps.

Of course, use double clamps everywhere you can and definitely below the waterline. Be careful and do not use oversized clamps on smaller hoses. The sharp bends around a small hose can cause clamps to eventually break. Do not overtighten! It creases the hose a lot and weakens it.
 
Double clamps

HeadedToTexas said:
Many raw water hose connections on Escape have double stainless steel hose clamps securing hoses to fittings, but not all of them. Do you guys have double clamps on all raw water connections at or below the waterline?
Click to expand...

Every hose on your boat that can be should be double clamped.
 
Double clamping raw water hoses well above the waterline such as those on an anti-syphon loop is a was of time and money.
 
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