I have a hose that's embedded in a large amount of fiberglass. I'm about to remove some of this glass and have the opportunity to replace what looks like it was a high quality reinforced exhaust hose. Unfortunately, this hose crumbled when I tried to clean it. What materials have you found last the longest? It's for a shower drain that will occasionally see water and cleaning solutions
What type of hoses last the longest?
- Thread starter Project_Mayhem
- Start date
I learned from several highly respected yard managers that 10 years is the average working working life of any hose because rubber and plastics dry out over time, becoming hard, brittle and prone to cracking and splitting. BOAT/US Magazine published an article several years ago in which they said old hoses connected to an open below-waterline thru-hull was the leading cause of boats sinking in their slips when no one is aboard. So do a little research into the best sink and shower drain line hoses and who has those brands for the best price. And buy hoses made for a particular "job"...don't even think of buying something because it's thicker and/less expensive.
--Peggie
--Peggie
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I would challenge that 10-year assertion. That is true of hoses that work in heat, oil, UV, or with constant mechanical stress. But a shower drain hose isn’t living that life. It’s wet, dark, cool, and rarely under pressure. That’s one of the most forgiving assignments a hose can have.
A reinforced PVC bilge or sanitation hose will outlast the boat. The failure mode of such a hose tends to be mechanical stress rather than chemical breakdown, and your application should be free of mechanical stress - though it is worth considering what each end of that hose will be subjected to.
I don't mean to undermine the point that hoses do wear out, over time, and that, in some cases, failure can ruin your day. And, it is important to match the hose to the job.
I am just disagreeing with that 10-year average. I would say that, with today's materials, when the hose is matched to the application, one should expect at least 10 years of service, without many exceptions. I would expect non-pressurized hoses to outlast the boat in nearly every case. The most notable exception would be the head output - though these are getting better.
In fact, as I get thinking about it, I can't recall ever thinking a hose was due for replacement that wasn't at least 15 years old, or so. Granted, I tend to just replace hoses any time I work on a thing, just because ... why not. I don't end up with a lot of old hoses - so maybe I have a skewed/optimistic view of hose longevity.
A reinforced PVC bilge or sanitation hose will outlast the boat. The failure mode of such a hose tends to be mechanical stress rather than chemical breakdown, and your application should be free of mechanical stress - though it is worth considering what each end of that hose will be subjected to.
I don't mean to undermine the point that hoses do wear out, over time, and that, in some cases, failure can ruin your day. And, it is important to match the hose to the job.
I am just disagreeing with that 10-year average. I would say that, with today's materials, when the hose is matched to the application, one should expect at least 10 years of service, without many exceptions. I would expect non-pressurized hoses to outlast the boat in nearly every case. The most notable exception would be the head output - though these are getting better.
In fact, as I get thinking about it, I can't recall ever thinking a hose was due for replacement that wasn't at least 15 years old, or so. Granted, I tend to just replace hoses any time I work on a thing, just because ... why not. I don't end up with a lot of old hoses - so maybe I have a skewed/optimistic view of hose longevity.
Many automotive hoses, even with a tough life, will outlive the useful life of the vehicle. The idea of putting some oversized tubing or pipe in there as a conduit came to mind today. This would allow for easy replacement down the line
What @Peggie Hall HeadMistress said w.r.t. 10 year lifespan is correct. Do bear in mind, that 10 year life span represents the time span where a hose can be relied upon to perform its expected function - the key wording here is "relied upon". We've all seen hoses last longer without a problem. But they are no longer reliable past that 10 year mark. Might they last 15 or 20 years? They might. The problem is the word "might".
On my boat, any hose that could cause a serious problem if it breaks is inspected every year and changed out every 10 years, irrespective of visual condition.
dj
On my boat, any hose that could cause a serious problem if it breaks is inspected every year and changed out every 10 years, irrespective of visual condition.
dj
Let me rephrase my question... Which material would you want your host to be made of if it's in an extremely difficult to replace location?
I'd suggest the flexible waste hose typically used in marine heads but only you know the diameter you need. No idea if what they make fits your needs.
dj
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,769
A good rephrase of the question.
Are there other considerations?
How long do you plan to own the boat?
If the materials will last 10 years, 20 years, 50 years what should the life span expectation be?
What conditions will the material be exposed?
Just random thoughts.
On my boat the builder chose a heavy non-collapsible exhaust hose that is resistant to chemicals for the shaft log connection. after 50 years it still appeared serviceable.
Are there other considerations?
How long do you plan to own the boat?
If the materials will last 10 years, 20 years, 50 years what should the life span expectation be?
What conditions will the material be exposed?
Just random thoughts.
On my boat the builder chose a heavy non-collapsible exhaust hose that is resistant to chemicals for the shaft log connection. after 50 years it still appeared serviceable.
I'll change the question to: which hoses should you replace really quickly? On the top of that list, I would put the flexible "dryer hose looking" plastic hoses that were used for sink drainage in our 2004 Hunter 306. I found cracks in them at 15 years which would have sunk the boat if I didn't have the habit of closing all thru-hulls when I leave the boat.
Second on my list would be the cheap, thin-walled white sanitary hose used for the head raw-water pickup (not SaniFlex), and for the head-to-antisiphon-back-to-head hose. This cheap white hose was also used routinely by Hunter for below the waterline applications which will sink the boat if/when they fail.
I've replaced all of the with the Shields black rubber, wire-reinforced hose you'd normally use for engine coolant. I replaced the waste-carrying sanitary hose with SaniFlex.
Second on my list would be the cheap, thin-walled white sanitary hose used for the head raw-water pickup (not SaniFlex), and for the head-to-antisiphon-back-to-head hose. This cheap white hose was also used routinely by Hunter for below the waterline applications which will sink the boat if/when they fail.
I've replaced all of the with the Shields black rubber, wire-reinforced hose you'd normally use for engine coolant. I replaced the waste-carrying sanitary hose with SaniFlex.
Based on what? The variability is so high here, this blanket statement doesn't hold water. (Couldn't resist the pun.)
I get the spirit of the "10-year rule" as a practical guideline, and agree it isn't bad practice, but it doesn't work as a literal statement of hose lifespan or "reliable" hose lifespan. There isn’t an ABYC spec, manufacturer guideline, or polymer-science source that gives a universal 10-year limit across all hose types. It's a folk heuristic that's been repeated so many times people treat it as fact.
Hose degradation depends primarily on:
- polymer type (EPDM, nitrile, PVC, polyurethane, silicone, etc.)
- temperature cycles
- chemical exposure
- UV/ozone exposure
- internal pressure
- vibration/mechanical strain
- installation (bend radius, clamps, chafe)
- ... and the complex interaction of all of these factors
When you compress all of those into a single calendar number, it stops being a material fact and becomes a conservative maintenance guideline - which is fine as long as we treat it as that. Replacing critical hoses on a 10-year cycle is good risk management - no disagreement there. But it doesn’t mean we cant trust any 11 year old hose, regardless of chemistry or conditions. Nor does it mean we can trust every 9 year old hose. Inspection is the key, not the calendar.
It's kind of like saying, "cars are reliable for 10 years - some might last longer, but you can't count on it." While it is true of some cars in some conditions and it's not a bad guideline, it is way overgeneralized.
What is true, and I think the reason this axiom persists, is the fact that the interplay of the variables is so complex, it is really hard to calculate the actual reliable life span of any single hose. So, we just say, "Well, if you have had the hose for 10 years, it doesn't hurt to replace it." And that's true.
But, what is also true is that most hoses don't need to be replaced profilactically. Sudden catastrophic hose failure is exceedingly uncommon, these days. I would go so far as to say it never happens in a non-pressurized and non-heated hose. Regular inspection is more than adequate prevention. But, of course, a better rule is, "Replace any hose you don't trust." If that means you replace an otherwise perfectly good hose on its 10th birthday, then that's what it means for you.
@Foswick lets not get into a pissing match. In a wide range of polymer longevity studies; while there are some specialized polymers that may be rated at 15 years - none of those are used in hoses. There is actually quite a lot of research to create polymer formulations that achieve or surpass 20 years.
You asked "Based on what?" My response is based on long term polymer testing of a wide variety of polymers.
Of course all the in-service conditions you mention are correct. It will lead to a wide variation in how much longer a hose may survive beyond those 10 years. But there are no tests that are non-destructive to test the integrity of the actual polymer in question.
dj
This should never have been used below the waterline. Hunter has really cut a lot of corners in the last 20-30 years it seems
OK, I'm just asking where one would find the evidence you mentioned. That isn't me calling you out. That is just me, having done a deep dive into this subject a few years ago, would genuinely like to see that. Or, we could just say that everything constructive has already been said, and move on.
Probably the simplest thing to do would actually be to work backwards. Look at the manufacturers warranties. See what kind of time frames their products are warrantied for. Trying to find the actual test data surrounding why they publish those numbers will be proprietary data and will be really hard to find. If I knew of a place to send you, I would be glad to do that.
Testing elastomers/polymers is a very complex subject. Any company that is doing this kind of testing will guard it's data very securely - at least that's been my experience. So in your "deep dive" into this subject, I'm not surprised you haven't really found anything. You won't find this information in AI either. AI does not have access to it. If you do find some data, I'd be very cautious interpreting it as it's likely missing most of the needed information to actually understand what it applies to and it's actual implications for actual usage. I see that sort of thing all the time.... This is a sailing forum. It's not a materials forum.
Only you can answer if you are satisfied with what's been said so far or not. That's not my call...
dj
is this just a troll post?
@Project_Mayhem - where do the ends of the current hose go? Like one end to a fresh water sink and the other to a water tank, or perhaps one end to a thru hull below the waterline and the other to something somewhere on the engine?
@Project_Mayhem - where do the ends of the current hose go? Like one end to a fresh water sink and the other to a water tank, or perhaps one end to a thru hull below the waterline and the other to something somewhere on the engine?
It's not a troll post but I'm glad to see the interesting views and debate that it's sparked. The hose between my seldom used shower drain (only used when hosing down the head floor a couple times a season) goes into my bilge. It goes through a heavy block of wood and resin filler on its way. As you can imagine, it's likely a major project to replace it. A very knowledgeable friend did a structural analysis of my boat and determined that the issue isn't with the compression block (at least not for the next few years), but with the mast step. So, this crumbling, yet seldom used hose, will stay in place for the time being.is this just a troll post?
@Project_Mayhem - where do the ends of the current hose go? Like one end to a fresh water sink and the other to a water tank, or perhaps one end to a thru hull below the waterline and the other to something somewhere on the engine?
My previous boat had a fuel filler and vent lines that were 47 years old before I replaced them. The filler hose had permeated due to a low spot where fuel liked to sit. The exhaust hose was the same with no obvious signs of degradation when I sold it. I did not cut into the hoses or run a camera inside for a deeper look. The shower drain hose in my Catalina looks like it was a good quality, reinforced hose, just like you'd see on a water injection port of an exhaust system. The exhaust system had similar hoses and they had lots of cracks in them when I bought the boat. I do believe that the right hose can last the remaining life of the boat in the application of a seldom used shower drain.
Feel free to carry on the debate
My suggestion in post #7 was to use flexible waste hose mainly because it's typically easier to install than other hoses. I made that suggestion as the particular hose you are changing out is non-critical. It almost doesn't matter what kind of hose you use. Your main concern is size and ease of installation. If this hose does begin to leak - what would it do? Anything serious besides get some water in the bilge?
dj
I think certain materials will outlast others but within the 10-15 year mark, it truly doesn't matter. I assume the water from a broken hose would eventually find its way into the bilge. It might expose the compression block to some water.
I think the practical solution in this case would be to use the existing hose as a conduit for a new, smaller hose. I've since replaced the shower wand style faucet and I can't see anyone actually using this tiny head in a 30' boat as a real shower. A smaller diameter hose would reduce the drainage rate but the couple of times a year that it's used between regular cleanings isn't a big deal to wait an a few more minutes
I think we all tend to get wrapped around "what's the absolutely best" axle.... I think we find there are so many projects on our boats, we end up trying to reduce them as much as possible. But really, it's just owning a boat. They need care and feeding... In your scenario - the once or twice a year the compression block sees water from whatever hose you choose will be trivial.
So from your description here - it seems to me - you are looking for the best "fit". You could line your current hose with tygon tubing - if the size needed is easiest to find in that material. All it's doing is transporting water from one place inside your boat to another place inside your boat...
dj