Replumbing entire boat

[LenBuchanan]

Ok, today I was out at the boat getting ready to flush out/clean out and sanitize my fresh water system. The boat is stored out side and every year I use about 25 gallons of RV antifreeze in the system. Run it in the tank, through all of the hot and cold outlets, drains, etc. So far I've never had a problem, until this year. My water tank is aft under the aft bed. I filled the water tank to rinse out the antifreeze and opened up faucets in both showers and sinks in heads and in galley. I noticed very low pressure. So I looked back in the aft where the tank is and there is water running in from the starboard side from somewhere. So, I shut off all of he faucets, which would/should cause the fresh water pump to shut off. NO LUCK.

I then start following the flow of water and of course in a place where I could never get to to splice a new line, I have a leak. Now, this is polybutylene pipe. The boat is a 1989 Jefferson.

So I am looking to replace ALL of the water system in the boat. Has any body used PEX? My first thought was PVC, but the polybutylene was ( in its day) flexible enough to bend around corners, where with PVC I would have to do 90 degree angle fittings.
Are the compression fittings different than the snap together for a splice or are they the same and still use the compression fitting to be attached to the PEX line?

Best way to do one section at a time using the old line as the 'fish' and tape the new to the old and pull through?

Any suggestions would be most appreciated.

 

[rslifkin]

I'd definitely go for PEX as a replacement for poly-b on a boat.

 

[Cigatoo]

Shark Bite makes Pex to Poly fittings. This will allow you to re plumb piece meal.

https://www.sharkbite.com/us/en/bra...h-to-connect-polybutylene-transition-coupling

 

[AnsleyS]

PEX is the way to go today. The crimp system is probably better but the shark bite is pretty easy. Get the cutter, it is greaT. PEX does not hold on to antifreeze taste as does the vinyl tubing. Go for it and take pictures for us.

 

[Ken E.]

I replumbed my boat a few years ago with Pex A. I used the Uponor system which expands the end of the tubing. Once expanded, the tubing slides over fittings and then contracts back to its original shape and size. My project worked out great and is a big improvement to the boat. Bear in mind that this is a big job since you will either be removing the old tubing or if you leave it in, trying to run Pex in tight quarters. I did my project when I had the galley and both heads torn apart for new counter tops, so there was room to work, at least in those spaces. Youtube has many videos on using Pex.

 

[LenBuchanan]

I will probably go with the total replumbing job as the poly lines are 33 years old. I won't be removing anything so I will use the old lines to pull the pex through. My only concern is I was going to use both the red and blue, but there are places in the boat, as the lines are all gray, that I don't know whether it is hot or cold line. Would it matter if I did it all in the same color or than be confusing?

I'm also hoping that I can get to all the 'T's' and such that is in the old poly lines.

I will definitely take and post pictures.

 

[Ken E.]

You will thank yourself many times in the future for staying with the color coding.

 

[Bacchus]

I replumbed a major portion of my previous boat system using PEX and agree its the way to go.
You have a few options to think about and decide before you start.
- Size(s) - many boats use 15mm and fittings avail online; big box stores carry 1/2" & 3/4" fittings, tube, crimps & tools.
- Fitting style- push-in, sharkbite, solid crimp tings, crimp bands, tubing expanding styles. Plastic & metal fittings. I'm sure there are resources online w +/- of them all. I've used a few different ones and will say they all work pretty well. The simple metal fittings are robust and relatively inexpensive. Plastic push in and sharkbite more $$.
The band type crimps fairly easy to remove if needed and Evan a tool avail for it. The solid rings harder to remove w/o damaging tube and need to splice a repair piece in.
- color vs white - either can work color anxious advantages but you can mark w a colored sharpie or shrink tubing as you install for the same easy ID. Probably depends on how much you need and whether colors create need for less than roll qtys (waste)

I'd say view some of the How To videos online of the various fittings, tools, etc. Before deciding.
I found dry fit and removal to crimp a section was helpful in some tight situations, leaving one accessible fittings to complete the install. Also helpful to think about areas that might need to be unassembled and needs some threaded / union type fittings to separate things.
If freezing is a possibility planning WH bypasses, 3 way valves, AF insertion connection point make life easy later on.

 

[Unclematt]

Last year I did a complete replumb with Pex. I agree it is the way to go. My tip is buy straight sections from a plumbing supply house. The coil I first bought from Home Depot was a SOB to run. It does not like to straighten. I ended up buying and using straight sections for all the long runs. I used extra clamps when I used any of the coil. The red and blue keeps easy track of hot and cold. I crimped mine, buy good crimpers.

 

[CaptTom]

I've been doing mine piecemeal. The remaining 42-year-old old Qest is holding up fine, but whenever I change or upgrade something, I use PEX. I have the crimp tool, but I'll use SharkBite (or equivalent) where I might need to disconnect it occasionally.

You'll still need to winterize. I've found it's easier to disconnect the water tank and pump the pink stuff right from the jug through the system. Less flushing in the Spring, too. I have a water heater bypass so I can drain that instead of filling it with antifreeze, too.

One option to consider is the way PEX is often used in homes; every fixture gets a home run to a central manifold distribution point. No "T" fittings to find (or freeze) and everything can be isolated for repairs and maintenance.

 

[psneeld]

Did mine with pex.

Used color system with clear being salt water systems.

Used stainless cinch with one handed cincher for ease in hard to reach areas. Fittings much cheaper than push ons

When I found spots requiring frequent service, then I figured I would go push on.

No leaks in probably 100 cinch fittings and all with my first pex project.

Did the whole job for a few hundred dollars, complete in a few days and probably easiest project on whole boat refit.

Did not do the AC system plumbing with pex, in retrospect, no reason now not to.

The biggest issue with salt water and pex was finding nylon fittings for all the applications.