Replumb with PEX

[Waywego]

Does anyone know if the gray pb lines in my Grand Banks are metric or SAE?

Home Depot sells John Guest push to connect fittings that work fine with those lines. There are a bunch of them on our boat repairing the constant leaks we have. This coming spring I will be replacing all the plumbing with PEX using the expander system. I think it is the easiest to install and my brother has the Milwaukee tool that I can borrow. The AquaPEX tubing is compatible with most other systems, so in a pinch, I can go to any Home Depot and buy a $45 tool and fittings to make repairs.

 

[Ken E.]

Home Depot sells John Guest push to connect fittings that work fine with those lines. There are a bunch of them on our boat repairing the constant leaks we have. This coming spring I will be replacing all the plumbing with PEX using the expander system. I think it is the easiest to install and my brother has the Milwaukee tool that I can borrow. The AquaPEX tubing is compatible with most other systems, so in a pinch, I can go to any Home Depot and buy a $45 tool and fittings to make repairs.

WWG, when using the expander system (Uponor) make sure to use PEX A tubing rather than just PEX, which won't work properly. The tubing is labeled with an A on it, so it's easy to identify.

 

[twistedtree]

And keep in mind that the fittings are definitely different for the Upnor expansion system. They are not the same as the box store generic PEX fittings for crimp systems.

So first decision is whether you want to use an expansion system or a crimp system.

If expansion, you must use PEX A, and fittings specifically designed for expansion systems.

If you use crimp, then you can use PEX A or B, and the fittings I think are all made to ASTME standards so interchangeable. I have certainly mixed and matched with not trouble over the years. But you need a crimp tool specific to the crimp ring system you choose.

On a boat I prefer the expansion system. Not metal rings to corrode or charge against other stuff is probably the big win. And I think it’s mostly easier to operate the expansion tool in tight spaces

 

[Waywego]

The tubing I mentioned, AquaPEX, is made by Uponor (Wirsbo) and is definitely Pex A tubing. Blue 1/2" AquaPEX

As twistedtree said, there is a lot to like about this connection system for use on a boat. The biggest drawback that I can see is that if you don't carry spare parts when cruising, you will most likely be making changes and repairs with crimp connections from a big box store (or calling a plumber). And that is not such a big deal to me when compared to carrying PEX tools that are rarely used except in an emergency. I already have way too many tools on the boat...

 

[Daveo]

I have installed a lot of pex using various fitting systems, I did a lot of heating installations, including lots of radiant, and plumbing retrofits in existing buildings where running rigid piping wasn’t possible. I like the the way the stadler viega fittings look, neat and tidy, the best but they require crimping tools I don’t have room for on board. I’m replacing all the 15mm pex on my boat with new 15mm manifold based system. I’m a fan of the john guest no tool fittings rated for 200 degrees f and 160 psi. They have a hand turned locking feature that might be more secure than the whale and similar designs, or might not but it makes me feel good. So why am I replacing everything? Well, nothing lasts forever and I have had two leaks in my 18 year old pex lines in the past 12 months. Both pinholes in hot water lines with no evidence of chafing or damage on the outside. Also several instances of push-on fittings starting to weep, they look fine but won’t re-seal. My best guess is o-rings dry out over time but just guessing. As for the pinholes I have no idea what temp the installed pex is rated for, what were they using in Taiwan in 2002? At least with a manifold and home runs I can isolate each and every branch. Also much easier to operate in freezing temperatures, just shut down the lines running to the outside or in heated spaces.

 

[Daveo]

Meant to add that these folks seem to have good pricing and I have received good service from them. No connection etc. etc. https://www.freshwatersystems.com/products/john-guest-union-tee-15mm

 

[Bacchus]

I replumbed a lot of water system on previous boat... both raw and fresh, hot & cold.
My ring crimp tool was large for some spots but I could dry fit many locations mark alignment w a sharpie and crimp where more room was available leaving a few exposed final crimps to finish.
Out of the whole job only ever had one leak and that was a wrong I forgot to crimp. Crimped it and never a leak after.
I have used different fittings but found the metal elbows & Ts and crimps to work best where space was tight and fittings had to be close to each other. Much smaller footprint and room required and able to not crowd under sinks etc w fittings.
I strategically placed screwed make / female to acts unions where future removal might be necessary.
I'd say diagram and plan ahead and the finished product will likely be neater and more user friendly in future.

 

[Ken E.]

As twistedtree said, there is a lot to like about this connection system for use on a boat. The biggest drawback that I can see is that if you don't carry spare parts when cruising, you will most likely be making changes and repairs with crimp connections from a big box store (or calling a plumber). And that is not such a big deal to me when compared to carrying PEX tools that are rarely used except in an emergency. I already have way too many tools on the boat...

I have thought about whether I should be carrying the expander tool and fittings in the boat, but I haven't done it. Also haven't had any situations where I've needed it either.....yet anyway. One positive thing about the Uponor fittings is that they will work with with flexible PVC potable water hose and a hose clamp in a pinch. For example, for 1/2" hose, the fit is very tight and you need a heat gun to soften it up a little before it will slide on the fitting, but it works fine with a hose clamp. I have one of my showers permanently plumbed this way in fact...it was easier for access than running Pex to it. The other brands of Pex fittings may be able to be used similarly - not sure on that.

 

[Waywego]

I have thought about whether I should be carrying the expander tool and fittings in the boat, but I haven't done it.

IWISS makes a manual tool with aluminum handles that might be a good choice for carrying on a boat. It is not as convenient to use, but perhaps a good compromise for those who want to carry an expander tool onboard.

IWISS ProPEX Expander-Uponor

 

[Brusky1000]

PEX is approved by the Florida Building Code for plumbing use. Is good stuff. Go forth and PEX it.
b

 

[twistedtree]

Keep in mind that commercial plumbing supply houses are nearly as prevalent as the box stores, and will have a much wider selection of parts. I’d be surprised if they don’t all carry expansion as well as crimp fittings.

 

[Waywego]

Keep in mind that commercial plumbing supply houses are nearly as prevalent as the box stores, and will have a much wider selection of parts. I’d be surprised if they don’t all carry expansion as well as crimp fittings.

In our area, most of the plumbers are using expansion fittings, and I suspect that is true in other areas as well.

You would need to have an expansion tool onboard if you go this direction. Stainless steel crimp tools are in the $45 range, but the least expensive expansion tool that I know of is about $130 and takes up a lot more space in the tool chest. I guess it depends on how much space and weight you want to dedicate to a tool that you hopefully won't be using very often. Being a tool collector, I would probably have one onboard if I had more space...

 

[Brusky1000]

Probably don't need as water pressure on boat is not that high...unless you are tied into a marina wtr. connection. I have 2 200 gallon stainless steel water tanks so I don't have the pressure problem. My water piping is copper and clear plastic with fiberglass (i think) reinforcement.