Converting to PEX?

I've been chasing a leak in the plumbing of our starboard fresh water tank since we purchased the boat and have decided that the 37+ year old 1/2" copper tubing is part of the problem.

I'm considering replacing everything with PEX using SharkBite push connectors. I've searched the forum for advice, tips and perspective but surprisingly nothing came up.

Has anyone done this before? Any concerns about brass connectors in the H2O system?

Pex with Sharkbite connectors is a very common and good solution for your fresh water system. Lots and lots of houses are built with copper tubing and brass connections so it should be fine for your boat.


David

Yes....been there and done that with PEX, for the same reasons. A 1971 boat, copper throughout. I was putting in new counter tops in the heads and galley and figured there would never be a better time, with a lot if the copper exposed. The Sharkbite Pex system is popular and seems to work well. However, I did mine with the Uponor system, which uses a Milwaukee tool to expand the end of the tubing, then slipping on the fittings. I decided on this system after talking to a couple contractors who use it. The project turned out very well.

I'm presently on the boat in Alaska, but if you send me a PM, I'll give you some specific info on vendors and prices when I get home, in about a month.
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Ken. Hatt Trick

I did a full replumbing of my boat last spring. I used pex pipes and crimped fitting as well as quick connect fittings. I used crimped fitting for connection that I know should be permanent and quick connect where I can foresee a removal for some reason.
Also I kept few length of soft tubing at pump and tank connections to temper vibrations.

L

I am using PEX as needed. Love the stuff. Replumed a 34 Mainship MK1. Great stuff. Now on my current boat, as needed. Cannot or should not be used as sanitary hose.

Replumbed my entire boat with Pex, except the steering, no more copper on my boat. Watch the Habitat and used stores for Sharkbite connectors, there are also cheaper generic ones but ygwypf.

If you look online you can find shark bite fittings a lot cheaper than your local home improvement store.
In case you do not know the same shark bite fitting will work on PEX and copper as long as it is the same diameter.

I replumbed a previous boat with pex. Used blue for cold and red for hot. Worked great. Bought the plastic benders used in homes to make 90s without fittings.

Lou_tribal said:

I did a full replumbing of my boat last spring. I used pex pipes and crimped fitting as well as quick connect fittings. I used crimped fitting for connection that I know should be permanent and quick connect where I can foresee a removal for some reason.
Also I kept few length of soft tubing at pump and tank connections to temper vibrations.

L

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+1.... and zero leaks with the pinch crimp fittings even with plenty of mofification changes since first install.

Bought the extra flexible pex online from SupplyHouse.com

Awesome. Thanks everyone. I plan to replace the feed lines between both tanks and the water pump with PEX and quick fittings for now as I'll likely need to re-route in the future. Some of the original cooper is under the water tank (outboard of the stringers) rather than inboard and accessible. I really don't know what they were thinking.

It'll be nice getting another 150 gallons online.

Lou_tribal said:

I did a full replumbing of my boat last spring. I used pex pipes and crimped fitting as well as quick connect fittings. I used crimped fitting for connection that I know should be permanent and quick connect where I can foresee a removal for some reason.
Also I kept few length of soft tubing at pump and tank connections to temper vibrations.

L

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I also re plumbed most of the fresh & raw water system w PEX. Prefer the crimp to quick connect in most situations...
They are less expensive... take up less space. A few quick connects in key locations allows future removal & mods if reqd.

Question: Are there plastic fittings for saltwater use? I want to install a saltwater washdown system for the bow and stern using PEX.

Used PEX for our saltwater system 14 years ago. No problems.

Tator

High Wire said:

Question: Are there plastic fittings for saltwater use? I want to install a saltwater washdown system for the bow and stern using PEX.

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SeaTech (or SeaTek?) fittings and tubing are another good option.

High Wire said:

Question: Are there plastic fittings for saltwater use? I want to install a saltwater washdown system for the bow and stern using PEX.

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Yes, but the crimp ones are not as easy to find though in my experience, but I didn't try hard on the web yet. Used a few brass knowing I will replace soon. Did a few yesterday.

Plenty of push on plastic fittings.... but more expensive.

psneeld said:

Yes, but the crimp ones are not as easy to find though in my experience, but I didn't try hard on the web yet. Used a few brass knowing I will replace soon. Did a few yesterday.

Plenty of push on plastic fittings.... but more expensive.

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I worry about anything that relies on spring steel or Chinese plastic below deck.
Found plastic at HD.

High Wire said:

I worry about anything that relies on spring steel or Chinese plastic below deck.
Found plastic at HD.

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The crimp I used are all stainless steel.

L

High Wire said:

Question: Are there plastic fittings for saltwater use? I want to install a saltwater washdown system for the bow and stern using PEX.

Click to expand...

The Uponor Pex system has no metal at all, stainless or otherewise. The tubing end is expanded using a tool, a fitting is inserted, and in 5 seconds or so the tubing contracts back to its original size, with the fitting now firmly in place. Works like a charm and nothing to corrode.

Ken E. said:

The Uponor Pex system has no metal at all, stainless or otherewise. The tubing end is expanded using a tool, a fitting is inserted, and in 5 seconds or so the tubing contracts back to its original size, with the fitting now firmly in place. Works like a charm and nothing to corrode.

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Thanks I'll check into it.

Love the pex, but one needs to carry spares if you plan to go off/shore. I looked, but didn’t find any pex in places like St. Tomas or Dominican Republic, but could always find a fitting of some kind to splice or repair a typical system. Never tested pex in cold climates, but I’d expect it probably needs thorough evacuation when it freezes, no?

"but one needs to carry spares if you plan to go off/shore."

Agree, copper tubing is world wide , and the flair nuts can be reused , so a roll of tubing and a good flair tool solves all future hassles.

Copper does not release chemicals into the water , plastic , who knows?

be careful if metric or US. all my pex is metric.

healhustler said:

Love the pex, but one needs to carry spares if you plan to go off/shore. I looked, but didn’t find any pex in places like St. Tomas or Dominican Republic, but could always find a fitting of some kind to splice or repair a typical system. Never tested pex in cold climates, but I’d expect it probably needs thorough evacuation when it freezes, no?

Click to expand...

Well, yes and, no.
The physical properties of pex, the "X" in pex, means it's cross-linked polyethylene. The cross-linking is on the molecular level, so what that means for application of the product is that the cross-linking is like DNA for what the material is born as. If it's tubing, it has that form in its base properties. So if you put a kink into the tubing, when heated gently, the kink will disappear as the cross-linked molecules return to their original state. If PEX freezes and is distorted, it will return to its pre-freeze shape with gentle heating. It the early days of the PEX market, there was a demo piece of tubing in the supply house. It was subjected to repeated abuse by the non-believers in the plumbing trade; it was remarkable how it would return to its undamaged state. That's not to say that it's indestructable, repeated freeze-thaws can do irreparable damage, a kink that creates a break won't heal, and of course the fittings are still subject to hydraulic freeze fracture. But the tubing itself is resilient by design. BTW, if you intend to heat it to bend it, it wants to return to a straight piece! Hence the forms for stub-outs & the like.

The sleeve method of joining to fittings takes full advantage of that cross-link property, using a piece of the tubing as a sleeve that's expanded with a tool then allowed to return to its original form, keeping tension on the joint. IMO, the best method of joining, although I use the copper crimps, reliable as well if the tool is not abused. Great stuff.

+1 for the Uponor system. Bought everything from Supplyhouse and re-did the whole boat. The stuff works great, is super easy, and does NOT leak. I bought the milwaukee tool on ebay. I also used it to plumb my diesel heater.

Westiculo said:

+1 for the Uponor system. Bought everything from Supplyhouse and re-did the whole boat. The stuff works great, is super easy, and does NOT leak. I bought the milwaukee tool on ebay. I also used it to plumb my diesel heater.

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There are several youtube video clips on this system. The Milwaukee expander tool allows you to make connections in tight areas, which was a big plus for my project.

Conversion fittings for Uponor

Which fittings did you folks use for converting from the threaded fittings on the tanks, pumps, etc... Looks like Supplyhouse has brass and stainless options. I have leaky water tank and hot line ball valves and plan to replace the funky metric pex from the tanks to the pump.

MiltonP said:

Which fittings did you folks use for converting from the threaded fittings on the tanks, pumps, etc... Looks like Supplyhouse has brass and stainless options. I have leaky water tank and hot line ball valves and plan to replace the funky metric pex from the tanks to the pump.

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In my case I kept a length of flexible hose from tanks as well as pump and used a barb-quick connect fitting to connect with pex.

L

Lou_tribal said:

In my case I kept a length of flexible hose from tanks as well as pump and used a barb-quick connect fitting to connect with pex.

L

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This is my plan as well. The immediate issue I'm trying to solve is to replace the feed side (tanks to pump) to eliminate a blind leak in the old copper feed lines. I'll replace both sides and connect up to the pump's existing hosing via a barb.

Eventually I'll replace the remaining copper plumbing with Pex.

Thanks again to everyone for the advice. I'll be attempting this project today and will try and post a few pics.

My understanding is that the pex will expand along with the ice.......

FF said:

"but one needs to carry spares if you plan to go off/shore."

Agree, copper tubing is world wide , and the flair nuts can be reused , so a roll of tubing and a good flair tool solves all future hassles.

Copper does not release chemicals into the water , plastic , who knows?

Click to expand...

I thought copper released so many chemicals into the water that it was used as anti-fouling paint?