Alternatives to normal sanitation hoses?

[BugzyCan]

There are a lot of marine places in Singapore. I am quite certain one of these will have the hose you need.


https://www.shipserv.com/country/singapore/SG

[BlackHeron]

You can get away with it for short runs where totally isolated from any movement, flexing or vibration. PVC can easily work harden over time from any movement and then eventually crack, causing a mess. Remember, that boats flex quite a bit in rough seas. They also expand and contract more than you would think as temperature changes.

Too much of this and over time it is subject to catastrophic failure. And if you don't think a busted "sanitation" line anywhere on the boat isn't catastrophic then it hasn't yet happened to you.

That said I use a piece of PVC inline on my own sanitation system in our boat. It is a well-supported straight run between the head and the tank and is connected into each end by a short section of flexible sanitation hose. SeaLand sells an adapter just for this purpose to go from marine sanitation line to 1-1/2" PVC plumbing pipe.

I have a a very short 30" run of hose going from the head up to an anti-siphon loop then down from there to the PVC adapter and the few feet of pipe going over the remote septic tank pitched fairly well. Then another adapter on the other side of that and about 18" more of hose before going into the tank.

2 years of daily use and it is still going strong. If I ever have a permeation issue I only have 3-4 feet of hose to replace. Much cheaper than the 13 or so feet I'd need if it were all hose. The 1-1/2" of PVC is only a couple of bucks should it ever become too plugged up to clean out. It's all pretty accessible and would only take an hour to replace when it comes to that.

https://www.westmarine.com/buy/seala...84?recordNum=4

[warrior 90]

Originally Posted by BlackHeron

You can get away with it for short runs where totally isolated from any movement, flexing or vibration. PVC can easily work harden over time from any movement and then eventually crack, causing a mess. Remember, that boats flex quite a bit in rough seas. They also expand and contract more than you would think as temperature changes.
https://www.westmarine.com/buy/seala...84?recordNum=4

I certainly agree to Your points and some common sense should be applied for the limits.
However the same could be said about the RV industry where PVC is standard in the sanitation system... lot´s of cuts and fittings despite flexing and vibration.
Also the PVC pipe is flexible I think when connecting to a fixed part/connection on the boat it might be good to use a section of hose.
In general I feel more comfortable with the PVC and to be honest.... to me it also looks a lot cleaner to the eye then the hoses all over the place in a tight space in some occasions.
The only hassle I see is adapting it to standard marine installations.

Hahaha, West Marine adapter 27 $.... what a rip off
I must be in the wrong business.
There are threaded PVC end caps that allow standard size threaded PVC hose connectors. Much of it is used in the green houses industry where those things cost peanuts.

Yes, in Your case it makes a lot of sense. I doubt that You ever need to replace it for reasons of material fatigue.

Another thing I like ..... PVC pipe is not so bulky and an easy to stow away spares on board. A few more pieces of hose, some adapters and.....

https://www.youtube.com/watch?v=E3WouuPBEL4

and the plumbing department is prepared for lot´s of surprises.

Cheers

[peghall]

...The problem here is that no one carries marine specific hose...

That's why I suggested you talk with the folks at Trident...they should be able to put you onto the TYPE of industrial hose sold locally that's suitable for sanitation.


--Peggie

[BlackHeron]

Yeah, thst price is ridiculous. When I bought mine with a portsupply account I think they were like $10/each and I still considered making a multi-fitting "go-from" adapter out of more available and cheap standard plumbing fittings instead because I balked at the price. But space was tight in the locker behind the head where I was locating the anti-siphon loop and this fitting made the nearest transition. I also had free delivery right to my boat because of the Chicago WM being a delivery hub at the time (It no longer is unfortunately, but I also don't live there any more.)

I am sure that if I had taken the trouble to have gone to a plumbing wholesale house there would be something available similar to this overpriced adapter for a buck or so. At least I didn't spend $27 each on them at WestMarine.

[taylormobile]

So the PVC I was referring to is rigid pipe. Be sure not to get foam cored. I would not recommend heating it to bend as it will compromise the impermeable inside and outside surfaces. I installed this in my first boat and when I sold it 20 years later there was still no odor. You can use PVC fittings for bends but you should use NSF approved flexible fittings at each end to allow flexing. I don't think boat builders use it because it takes more labor to install rather than just running the flex tube. I used this material on our current boat and 4 years later no odor.

Steve

[warrior 90]

Originally Posted by BlackHeron

I am sure that if I had taken the trouble to have gone to a plumbing wholesale house there would be something available similar to this overpriced adapter for a buck or so. At least I didn't spend $27 each on them at WestMarine.

Yes, finding solutions at a local place. I think this is what we should do. For this kind of $$ we might even get invited for dinner from the manager.
I don´t believe this fitting was made specific for marine application.
But that´s how the guys make a living. I consider 100% profit margin a good business but not in the marine industrie. There is always somebody in need that the bastards can charge for a piece of garbage the price of gold.

Originally Posted by taylormobile

I don't think boat builders use it because it takes more labor to install rather than just running the flex tube. I used this material on our current boat and 4 years later no odor
Steve

It seems everybody has good results but we still keep using that expensive stuff that many report having bad odors on the boat.
Saving cost running flex tube ?
I think it´s more a question of mentality and nobody bothers even so all boat owners have the same problem with those sani hoses.
Reality is ... many times it is really a lousy job to change those hoses and often also quiet complicated with all them hoses and fittings in hard to access places. I think there is lot´s of room for improvement.

But then for example in places like cruiserforum there is not much attitude for change on the subject.
There are some that write about PVC tube but when somebody like SpaceRnglr in Singapur is in need nobody stands up to recommend PVC tubes as a possible valid solution.
Feels like PVC tubes on a boat in general are considered as a junkyard solution with an image of cheap and bad quality.

Well, it seems first of all it takes care of the funky odors and second it seems in some cases PVC tubes last longer then the lifetime of the boat.

Maybe there are some users that can talk about their negative experience with PVC tubes ?
Till now I only know of negative experiences with all kinds of sanitary hoses that are expensive and don´t fix the problem.

Cheers

[BlackHeron]

There are PVC plumbing fittings specifically designed for septic use (DWV: Drain, Waste, and Ventilation) in addition to the regular PVC fittings just designed for water delivery.

DWV fittings are different with elbows and T's shaped for better flow of solids and septic vent gasses, and designed to take the punishment of being rodded-out, and the direction of flow being a consideration.

Keep this in mind as rigid PVC fittings are built into a marine septic system and use DWV elbows and T's when assembling the PVC pipe.

[agb512]

ABS. Cheap, strong, totally impermeable.

[skipgundlach]

Originally Posted by warrior 90

clipping all the very nice long post - you can see it a few frames up...

I, for one, promoted PVC to SpaceRnglr, and noted his flexible joint issue.

As to running hoses, when the lid's off and the cabinetry isn't in, running hose, even though it's massively more expensive than PVC, is quick and easy, cutting assembly labor costs. And, if it didn't have the accessibility (albeit very contorted as in my forward head), there might be instances where - should it ever need it - replacement (such as scale fouling) would be either impractical or impossible. This said from a firm believer in PVC; I went to some effort to replace hose in the forward head!

So, mostly, you'll see hose, and for those folks who CAN'T do the umpty-pumpty to keep them clear, the ability to replace them, at whatever cost, is critical.

As to the junkyard solution, it's actually considerably better, methinks - but then, I've been weird all my life; at almost-74, I likely will remain that way!

L8R

Skip

[SpaceRnglr]

Well, it took me a while to respond as I got busy in the boat yard and then on other things. In the end, i chickened out and just bought hoses from the USA and shipped them to Singapore. ezbuy.sg has freight forward from the USA for S$8/kg so shipping wasn't that bad in the end...

I didn't put this in my original post, but I had considered PVC. My hose runs are relatively short but curvy as they would have to go through narrow cabinets and follow the shape of the hull up to the anti-siphon valve. I could have used pvc for some but not all of it. Given infinite time I would have tried to make PVC work to save cost, but in this case I wanted to just offload the job to the yard. Since I supplied the hose it was one of those time consuming / fiddly jobs that is easy to simply get them to do without much oversight. So now all hoses are replaced and I have new anti-siphon vales (that have access to maintain the valve).

I hope someone else is braver than me and finds a good alternate hose and can report on experience. It would be great to have a hack that saves some cost over the exorbitant (and hard to find) sanitation hoses...