Seacocks: your Operating Procedure

[wingless]

On my boat I perform periodic removal, inspection and replacement of all underwater components.

[HopCar]

"a. Hopcar's experience is not universal. Perhaps he chosen very poor wire hose, misapplied it, or misinstalled it, but I have had very different experience, both in boats and long industrial practice.
b. Wire hose can fail prematurely if misused, but the failures tend to be leaks rather than catastrophic failures. I've seen many of both. I suspect this is in the ABYC's reasoning. Thermoplastic hose can more easily rupture completely."

Thinwater, I sort of agree with you. I've never seen a catastrophic failure of a good quality wire reinforced marine hose. I have seen a lot of them replaced when the wire rusts internally and causes the outer layer to fail. I'm not basing my opinion on just my own boating experience but on more than forty years of customers bringing bad hose samples to my store looking for replacement.

I realize there are situations where you have to use wire hose. I just don't use it where I don't need to.

Now that you mention it, I can't think of one time I've seen a catastrophic failure of either hard or soft wall marine hose. That's why I'm comfortable leaving my seacocks open.

Hose of both types goes bad slowly and gives you plenty of warning before it fails.

Wait a minute, let me think this through. I believe that soft wall hose lasts longer than hard wall hose. Hard wall hose costs more than soft wall. I sell marine hose.

I've changed my mind. Everybody should use hard wall hose for everything!

[TacomaSailor]

Each of our transducers has a screw in plug that came with the transducer. We also have a soft wood bung hanging from each, and every thru hull, including transducers. The tapered bungs can be driven into any broken thru hull to stop the inflow if really necessary.

[CarlF]

I follow Hopcar's routine.

I have never seen (or witnessed) a high quality hose properly double clamped to a seacock fail at anchor or dock. Even if it were to happen, lives are not put at risk.

What I have experienced once (and witnessed more times) is failure of an old hose underway. This is rarely noticed until the water has risen above the cabin sole because no one hears the bilge pump running against the other noises of the boat underway (it's better since high water alarms have become common). At that point, locating and reaching the right sea cock in deep bilge water is difficult. Lives are immediately at risk.

So I hope all who insist on closing their seacocks, also replace all hoses connected to those seacocks on a regular basis - I do it every 10 years even if the hose looks great.

Rubber and vinyl ages. How many of you have 10 year old tires on your car?

[Stu Jackson]

Originally Posted by Tayana42

I'm more worried about transducer and speedo paddle wheel with no sea cocks than I am about hoses with sea cocks. What do people do about the possibility of leaks or failure there, aside from tapered wooden plugs?

My speedo has a dummy replacement plug, in the drawer right next to the hole.

Never thought about the depth 'ducer, seems a permanent mount, not removable.

[Cheechako]

Originally Posted by HopCar

I shouldn't admit this because I'll catch a lot of crap for it but I never close my seacocks. I do exercise them several times a year.

I've never had an unpressurized hose fail and I doubt one ever will.

I keep a good eye on the condition of my hoses and I use good quality hose.

I avoid using hose with wire in it. The wire will rust and damage the hose.

I use high quality type 316 stainless hose clamps and keep an eye on them as well.

If I was worried about it and they were hard to get to, I'd probably install remotely activated seacocks.

In a boat I know well and trust, I never close them either. A couple times I have purchased a spool of hose to replace the hoses on my boat, about half way through replacing I'm kicking myself because the hose is so tough and good I cant even get it off readily.

[TacomaSailor]

CarlF said "I have never seen (or witnessed) a high quality hose properly double clamped to a seacock fail at anchor or dock. Even if it were to happen, lives are not put at risk."

I have - well sort of - the sordid details follow!

I installed a Spectra watermaker system on our boat in spring 2000. The connections to the seawater suction lines on both 3.8 GPM feed pumps were very high quality hose and stainless steel double hose clamps.

In the fall of 2003 I made an overnight run from Bahia San Francisquito to Santa Rosalita on the central east coast of the Baja California Peninsula. I ran the Spectra watermaker for five hours during the sail south.

In retrospect, I should have been curious why our one-quarter full 85 gallon water tank did not fill up when the 16 GPH Spectra system was feeding it for five hours.

After I docked at Santa Rosalia I did get curious.

I eventually discovered that one of the two feed pump hoses had come loose on the discharge side. The feed pumps are in a compartment below the waterline that is plumbed to the bilge to carry away any overflow or seepage.

It turned out I had been pumping 3.8 GPM of saltwater into the bilge for five hours and only pumping 7 GPH of freshwater into the tank.

The STAINLESS hose clamps were both rusted, rotten, and had broken.

I checked the STAINLESS clamps with a magnet and found that the "made in China" clamps were not stainless and were magnetic.

I then checked everyone of the other 30 STAINLESS STEEL hose clamps in the Spectra System and found that almost (not quite all) ALL of them were cheap ferrous clamps. Many of those 30 were on the verge of rusting thru and breaking off and several of the clamps had in fact broken but the hose had not yet come off.

I keep all my boat expense receipts and was able to verify that I had paid top dollar at WEST Marine for stainless hose clamps and had in fact received cheap non-stainless clamps.

I then checked dozens of other hose clamps on the boat and found about half of them were also magnetic and not good stainless.

I know cheap clamps are an old story but sometimes even the best effort to avoid them is not sufficient.

I SHOULD HAVE checked each clamp with a magnet BEFORE I installed them.

Ever since then, I check every clamp I buy with a magnet before I pay for them.

[wingless]

Here is information from McMaster-Carr on hose clamp material selection.


Type 301 Stainless Steel Clamps—Have a Type 301 stainless steel housing and band for very good corrosion resistance. The zinc-plated screws have fair corrosion resistance. The Type 410 stainless steel screws have good corrosion resistance. The Type 305 stainless steel screws have very good corrosion resistance.

Type 316 Stainless Steel Clamps with Type 316 Stainless Steel Screw—Have excellent corrosion resistance.

[Cheechako]

Originally Posted by TacomaSailor

CarlF said "I have never seen (or witnessed) a high quality hose properly double clamped to a seacock fail at anchor or dock. Even if it were to happen, lives are not put at risk."

I have - well sort of - the sordid details follow!

I installed a Spectra watermaker system on our boat in spring 2000. The connections to the seawater suction lines on both 3.8 GPM feed pumps were very high quality hose and stainless steel double hose clamps.

In the fall of 2003 I made an overnight run from Bahia San Francisquito to Santa Rosalita on the central east coast of the Baja California Peninsula. I ran the Spectra watermaker for five hours during the sail south.

In retrospect, I should have been curious why our one-quarter full 85 gallon water tank did not fill up when the 16 GPH Spectra system was feeding it for five hours.

After I docked at Santa Rosalia I did get curious.

I eventually discovered that one of the two feed pump hoses had come loose on the discharge side. The feed pumps are in a compartment below the waterline that is plumbed to the bilge to carry away any overflow or seepage.

It turned out I had been pumping 3.8 GPM of saltwater into the bilge for five hours and only pumping 7 GPH of freshwater into the tank.

The STAINLESS hose clamps were both rusted, rotten, and had broken.

I checked the STAINLESS clamps with a magnet and found that the "made in China" clamps were not stainless and were magnetic.

I then checked everyone of the other 30 STAINLESS STEEL hose clamps in the Spectra System and found that almost (not quite all) ALL of them were cheap ferrous clamps. Many of those 30 were on the verge of rusting thru and breaking off and several of the clamps had in fact broken but the hose had not yet come off.

I keep all my boat expense receipts and was able to verify that I had paid top dollar at WEST Marine for stainless hose clamps and had in fact received cheap non-stainless clamps.

I then checked dozens of other hose clamps on the boat and found about half of them were also magnetic and not good stainless.

I know cheap clamps are an old story but sometimes even the best effort to avoid them is not sufficient.

I SHOULD HAVE checked each clamp with a magnet BEFORE I installed them.

Ever since then, I check every clamp I buy with a magnet before I pay for them.

Just so you know, most clamps with "Stainless Steel" on them are stainless on the band only. The screw is often steel.
As noted above in another post the 316 ones should be Stainless throughout. Although I'm not sure the screw on those may be 400 series stainless to avoid galling...? if so the screw will be magnetic anyway.
In a related thing, the white plastic hose often used for sanitary and other uses is real prone to splitting. If it's hard to get on the fitting (and it usually is) any minor clamp gouge can cause a total failure. I quit using it entirely for any purpose.

[Hudson Force]

I will continue to double clamp my hoses with quality SS hose clamps; however, at almost all times that I have a purpose to remove a hose I have great difficulty removing it even after both clamps are off. I sometimes end up cutting the hose from the barb so I wont risk damage by twisting, pulling and heating the hose! I believe many failures are due to corrosion of fittings other than the clamps or use use of clamps to hold an improperly sized hose,- even tape wrapped over the hose barb to adjust for a larger sized hose.

[DumnMad]

Originally Posted by HopCar

"a. I've never seen a catastrophic failure of a good quality wire reinforced marine hose. I have seen a lot of them replaced when the wire rusts internally and causes the outer layer to fail. I'm not basing my opinion on just my own boating experience but on more than forty years of customers bringing bad hose samples to my store looking for replacement.

I realize there are situations where you have to use wire hose. I just don't use it where I don't need to.

Now that you mention it, I can't think of one time I've seen a catastrophic failure of either hard or soft wall marine hose. That's why I'm comfortable leaving my seacocks open.

Hose of both types goes bad slowly and gives you plenty of warning before it fails.

HopCar, what are the warning signs? I can guess but have zilch experience compared to yours.

[wingless]

The hose warning signs I've observed are exterior cracking. This happens earliest where the hose is bent on a smaller radius.

[HopCar]

"HopCar, what are the warning signs? I can guess but have zilch experience compared to yours."

Like wingless said, the outside can get dry and crack. The type with wire will show rust stains on the outside. A hose can also look good on the outside but feel mushy when you squeeze it. Some of the molded hoses used on engines feel mushy from the start so you have to watch for drying out with them.

I'm talking about the heavy rubber fabric reinforced hoses typical on boats.

The vinyl hoses seem to lose their plasticizer and get hard and even brittle. Test by squeezing, watch for yellowing.

[HopCar]

"My speedo has a dummy replacement plug, in the drawer right next to the hole."

Isn't a speedo a type of swim suit? In that light, the above sentence takes on a whole new meaning.

[DumnMad]

Originally Posted by HopCar

"HopCar, what are the warning signs? I can guess but have zilch experience compared to yours."

Like wingless said, the outside can get dry and crack. The type with wire will show rust stains on the outside. A hose can also look good on the outside but feel mushy when you squeeze it. Some of the molded hoses used on engines feel mushy from the start so you have to watch for drying out with them.

I'm talking about the heavy rubber fabric reinforced hoses typical on boats.

The vinyl hoses seem to lose their plasticizer and get hard and even brittle. Test by squeezing, watch for yellowing.

Thanks HopCar. Much as I guessed but needed to confirm. All my hoses and fittings check out OK and have above water anti syphons so the only seacocks I close are to the Toilets.(I caught one overflowing once.)