Check Your "Made in China" Hose Clamps!

[svHyLyte]

We are very diligent about house-keeping and maintenance on our yacht in order to ensure that things work when needed. Accordingly, I was very surprised this past weekend when I discovered that one of the supposedly Stainless Steel hose clamps on the raw-water intake side of our forward head had broken and slipped down the hose (which I found while doing the weekly "thorough" cleaning of the area behind the head with a bucket of hot soapy water.)

Upon inspection I discovered that rust had developed under the screw clamp, which was out of easy sight on the bottom side of the hose, until enough had built up to generate sufficient pressure to rupture the perforated strap around the hose. Further inspection revealed that all of the hose clamps on this installation--which is less than 18 months old--were showing similar deterioration and rust build-up.

These Stainless hose clamps--ranging from 3/4's to 2 inches in diameter--were purchased a West Marine and were not inexpensive. Further inspection revealed that, in each case, the rust seemed to emanate from the point where the ends of the perforated straps where spot welded to the under-side of the screw assembly. Evidently, this spot welding process changes the properties of the material enough to allow rust to develop. Rust--or iron oxide--reportedly has a volume approximately 600% of the volume of the iron consumed as rust is formed. Hence-its formation under the strap can build-up sufficient pressure to rupture the strap. (Inspection of several new-unused clamps--in the spares box revealed that all had the beginnings of rust in the same location and all bore the inscription "Made in China".)

We are now going through the yacht and replacing any hose clamps that show similar deterioration and which, when found, also seem to be relatively recent replacements. Interestingly, the hose clamps that are in the best condition are the original 1985 era stainless steel clamps used by Beneteau when the yacht was constructed. These have no welds at all. The screw assembly's are held in place with small clips that fit into slots cut into the edges of the straps. The nice thing about these is that the straps can be threaded into the screw assembly's and then--once the strap is passed around the hose--the strap ends popped into place on the ends of the screw assembly's with one hand.

I do not know if this problem is isolated to West Marine's supplies so this should not be considered an indictment of that Company. I do know, however, that at several dollars each, these items should not fail in this manner--regardless of the supplier--and that doing so could be catastrophic. If I can track down a source for the original, unwelded type, straps I shall post the source and I will appreciate a referral is anyone already knows of a source.

s/v HyLyte

[Kanani]

I would recommend buying only S/S clamps made by a major US manufacturer (like Ideal) and are made of "316" stainless.

When purchasing S/S clamps, take a magnet with you. You will find that most S/S clamps have a ferrous metal screw in them (The clamp is S/S but the screw isn't). I'll bet that is what the problem is with the clamps that you have. Avoid these like the plague. If the clamp has any attraction to the magnet, avoid it. It has ferrous metal in it and it won't last long.

Always double clamp all hoses. Be careful not to scratch or ding the clamp screw with a screw driver. It's best to use an appropriate sized nut driver to tighten hose calmps. If you tighten a clamp too tight and you feel it start to strip, pull it off and replace it. "316" S/S clamps will strip more easily so buy plenty. Return what you don't need (throw away the stripped ones).

Hose clamps should be taken very seriously. They are your defence against sea water intrussion. I think that more boats sink from failed hose clamps than any other one single cause.

[ssullivan]

All good advice.

I had the exact same problems with cheap hose clamps corroding (without even being in contact with salt water at all) in less than a year.

[David M]

I don't think it is so much a matter of where it is made so much as it is a factor of being a crappy clamp. Some of the cheaper stainless does contain iron. It's still considered stainless...but obviously, don't buy it. Also, stainless can go active (start decaying) if it does not have access to oxygen. I know that sounds counterintuitive, but it is true. It's best not to coat critical stainless steel things like hose clamps with anything. It's why "dripless"..hah! shaft seals have a water feed from the engines raw water system...also to eliminate any sort of air entrapment (bubble) as well.

Always use the type of clamps with the unperforated bands for anything that is below the waterline. Like these clamps: West Marine: Heavy-Duty Type 316 Stainless-Steel Hose Clamps Product Display These clamps in particular are a metric size, so buy the metric size nut driver which makes tightening them down much easier than trying to hold a slot screwdriver exactly in place...usually while in some awkward position, around a blind corner, with only one hand available ...right? We have all been there.

The clamps that are perforated are not nearly as strong and they strip much easier in my experience. Like these: West Marine: Hose Clamp Kit - 1/4" - 5/16" Stainless Steel Product Display

[Alan Wheeler]

Hoseclamps break. No matter what brand or where they are made. It is a fact of life. Pure 316 clamps because they work harden with vibration. So there is no foolproof clamp.That is why you double clamp everything.
Totaly stainless clamps have the nasty habit of the screw coming unwound. I use a stainless band with a galv screw. The screw does oxidise slightly and locks the clamp. I have had no trouble lossening when I need to.
On most of my "mission criticle" connections, I use the larger clamps that have a bolt to tighten them. Sorry, can't remember the name.

[Jackstee]

Hi Guy's

Actually, 316 S/S is the lowest standard of stainless that is classed as good. There is at least a dozen standards above it , but, it is ok. We specify it as a minimum for industrial kitchens but, as part of my job demands, I always carry a small magnet. You would be supprised what get slipped in.
It does not have to be a big magnet, just something that you find on a fridge door.

Steve

[Microship]

I tend to avoid West for hardware except in emergencies, as one never knows what alloy is in the bin and prices are absurd... I've been bitten a few times with crevice corrosion from 18-8 or other cheap stuff. The best fastener and hardware source I've ever found is McMaster-Carr, which ships quickly and has just about everything imaginable for industrial supply... if you click "hose and tube clamps" in the first section, it will show the options (including those with all-316 hardware for maximum corrosion resistance).

Cheers,
Steve

[David M]

Originally Posted by Alan Wheeler

On most of my "mission criticle" connections, I use the larger clamps that have a bolt to tighten them. Sorry, can't remember the name.

T-Bolt band clamps. I use them on my 6 inch exhaust system, double clamped, where you definitely do not want a hose clamp breaking. These work well for when you need to pull a large diameter thick walled hose really tight. They have a nylock nut so you don't have to worry about them backing off. I have seen these break through corrosion and metal fatigue..so as someone said earlier, no hose clap is unbreakable.

Clampco Products: Manufacturer of T-Bolt Band Clamps, Spring-Loaded Clamps, Worm Gear Hose Clamps, and V-Band Couplings for all industries

[David M]

sorry..double post.

[Triton318]

Originally Posted by David M

Always use the type of clamps with the unperforated bands for anything that is below the waterline.

Why unperforated? Just curious -- I've always used the other kind and didn't even know about unperforated clamps.

[GordMay]

Cheaper clamps have perforated bands with sharp edges, which tend to abrade the hose; and carbon steel screws with a stainless steel band, which causes (galvanic) corrosion, and premature clamp failure.

“AWAB” makes hose clamps with a smoother inside surface (threads are pressed, not perforated), and also have a relief cuff at the edges - both features reducing damage to the hose when clamp is fully tightened.

An excellent "AWAB" clamp - and an "el cheapo" clamp

[Kanani]

Originally Posted by Alan Wheeler

Hoseclamps break. No matter what brand or where they are made. It is a fact of life. Pure 316 clamps because they work harden with vibration. So there is no foolproof clamp.That is why you double clamp everything.
Totaly stainless clamps have the nasty habit of the screw coming unwound. I use a stainless band with a galv screw. The screw does oxidise slightly and locks the clamp. I have had no trouble lossening when I need to.
On most of my "mission criticle" connections, I use the larger clamps that have a bolt to tighten them. Sorry, can't remember the name.

I hate to say this but that is just bad advise.

I have had the same 316 all stainless clamps on my boat for at least 10 years. I loosen and retighten them yearly and replace them if I strip them. I've never had one come loose or break (I have 13 thru-hulls).

I have made countless deliveries on vessels that I have had to require the owner to re-clamp the entire boat due to broken clamps from galvanized screws in S/S clamps (in almost every case).

I delivered a brand new 65' sloop from (Wangerai) NZ to Fiji in '96. I made the owner of that vessel replace every clamp on the boat for the same reason. The vessel had been comissioned 6 months prior and I found 8 broken hose clamps.

I take deliveries very seriously and I won't leave port in a boat that I haven't thoroughly inspected and approved safe for myself and crew. Hose clamps are my #1 priority. In most cases, I just close all of the thru-hulls that aren't mandentory (engine and 1 head).

[cat man do]

I've never had one come loose or break (I have 13 thru-hulls).

An awful lot of through hull's and an unlucky number.

I'll have 3 through hulls in 1 hull and 2 in the other.

ALL have ball valves

Engine water in will have a manifold with multiple water outlets, ALL with valves

Dave

[Kanani]

Originally Posted by cat man do

An awful lot of through hull's and an unlucky number.

I'll have 3 through hulls in 1 hull and 2 in the other.

ALL have ball valves

Engine water in will have a manifold with multiple water outlets, ALL with valves

Dave

I don't blame you. That's just the way my boat was built.

1. Engine intake.
2. Aux engine intake
3. Galley intake
4. Galley exhaust.
5. Forward head intake.
6. Forward head exhaust.
7. Forward sink exhaust.
8&9 Are at water line, bilge pump exhaust.
10. Aft head intake.
11. Aft head exhaust
12. Aft head sink exhaust.
13. Aux engine exhaust.
I forgot about #14 because it is the hardest to get to......Main engine exhaust, out the center transom at the water-line.

See.....not so "Unlucky" after-all.

Yep.....a lot of thu-hulls. All with serviceable ball-valves.

[Therapy]

Originally Posted by Kanani

I don't blame you. That's just the way my boat was built.


See.....not so "Unlucky" after-all.

Yep.....a lot of thu-hulls. All with serviceable ball-valves.

And 14 plugs to have.