Any Reason Not To Use PEX On A Boat?

[seahag]

I'm going to rig up a deck washdown pump due to a new member in the family (dog). Was going to do the typical reinforced hose routine but thought of all the pex parts and pipe I have laying around from doing bathroom remodels; seems like it would be a winner on a boat, especially if Alaska ever freezes again, which hasn't happened much since I came here three years ago.

Any experiences or thoughts about this? Also, I already have a 4 GPM pump and would like to locate it near the thru hull, which may be about 5-6 feet lower than the outlet; any worries about pumping ability?

Thanks-
Scott

[a64pilot]

If your familiar with Pex and have the tools, it's great stuff.
I think for most that don't have the crimping tools, maybe not.

[Stu Jackson]

I recently replumbed the whole boat. I shudder to think about how difficult it would have been to route the hoses if they weren't flexible. I don't know how flexible Pex is, but there were many places that having to install two elbows would have been a real big PITA. Plan ahead.

[a64pilot]

Pex is awfully flexible, I'd be surprised if that is not what is used in new boats.
Pex as long as it is kept out of UV will last longer than we will, but I have been told that UV will kill it quick.
I used to think copper was forever is a house, then I learned it's not and had my house re plumbed with Pex.

[ranger58sb]

Our whole boat is plumbed with PEX, that way from the factory...


-Chris

[sailorchic34]

Myself with going on 40 years designing and specifying plumbing systems think PEX is the perfect pipe material for the typical yacht. I like the push on fittings better then the crimp fittings as a crimp fitting reduces the inside pipe diameter and acts as a restriction orifice. It would not really be a problem on a boat, but the engineer in me, likes keeping the pipe inside diameter constant. Using slip on fittings allows for full bore fittings and easy changing, say if you want to add a deck shower.

Even better if you had an older boat plumbed with say pvc as mine was, you can slip the 1/2" pex inside the 1/2" PVC. This as tubing size is external diameter and pipe size is internal diameter. Made it easy to replum my boat way back when.

[a64pilot]

I didn't think about the "sharkbite' fittings. I've only used Pex in the house and there I used the crimpers.
Your worried about restricting by crimping, but you slid one pipe inside of another ?

[rwidman]

PEX will be fine for your project if you don't need the flexibility of hose. Qest compression fittings are good for PEX and are less expensive and lighter than Sharkbite fittings.

[misfits]

Originally Posted by sailorchic34

Myself with going on 40 years designing and specifying plumbing systems think PEX is the perfect pipe material for the typical yacht.

From some of your previous posts regarding mechanical stuff, I knew I liked you for a reason.

Pex is an awesome product for a boat but personally I like the expander rings like in the Wirsbo/Upnor line in lieu of the crimped rings used by other manufacturers. I have never seen an expander ring leak, can't say that for the crimped rings. Even Watts is moving to an expander ring now. You can also purchase 3/8" pex which when thinking about boats should help conserve water when compared to 1/2". Of course this does depend on many faucets you want to operate at any given time. On a boat, it's your fresh water...
Many plumbing supply houses that sell this product aslo will rent the tools. In my opinion it's best to not mix & match products. Stick with one manufacturer for everything. Or you could end up like this

[sailorchic34]

Originally Posted by a64pilot

I didn't think about the "sharkbite' fittings. I've only used Pex in the house and there I used the crimpers.
Your worried about restricting by crimping, but you slid one pipe inside of another ?

Actually the pipe slips into the sharkbite or other slip on fittings. There is no loss of inside diameter so no extra pressure pressure or increased velocity. Generally not a problem with a boat anyway. That flow restriction is why many pex home systems use a manifold system with branch lines to each fixture. It's not a big deal with one or two fixtures, but it adds up for a larger system.

Note that the sharkbite fittings are rated to 80 psig which is standard in the plumbing code in the US.

I'm still a little gun shy with crimp fittings. But that's due to the old 1970's-1980's PB systems which had aluminum crimps and copper insert fittings. Differential thermal expansion between the aluminum crimp ring and the brass fittings, caused a ton o leaks way back then. Lots of unhappy home owners.

Though the current PEX crimp systems do not seem to have that issue.

[sailorchic34]

Originally Posted by misfits

From some of your previous posts regarding mechanical stuff, I knew I liked you for a reason.

Pex is an awesome product for a boat but personally I like the expander rings like in the Wirsbo/Upnor line in lieu of the crimped rings used by other manufacturers.

Upnor is good stuff and that is a good system. A tad pricey for the tool for the typical home or boat owner. For the pro, it's works. And that is what is important.

[zboss]

Just completed redoing ours using pex. We used a mix of push-on sharkbite fitting and watts push-on. I think between the two, I prefer the sharkbite. Pex is plenty flexible but it will kink if pulled to tight - we used maybe six 90 degree bend supports for going around tight corners. The 10 foot sections of straight pex was a bit easier to use than the rolls. It's only about 35 cents a foot or so.

The UV light is supposed to break down PEX but if you look at the huge rolls of pex rolled up on the sidewalk in new communities for months at a time, I'm not sure its as much of an issue as we are being led to believe. Anyhow... its super easy to cut out a busted line and fix it.

FYI, I found the best tools were in fact the cheap sharkbite tools sold at Home Depot. I tried using a fancy tubing cutter but that didn't produce as good a cut as the simple razor blade device. Also, the tubing reamer is nice to have because it cleaned up the edges and allows you to mark the depth on the tube that needs to be inserted into the fittings.

To help with the installation around bends or going through hard to reach areas, we used one of those 6 foot flexible fiberglass rods. We would push the rode through or around whatever then slide the pex onto the rod. When we reached the end of the rod we would remove the rod then move to the next location.

[Mikado]

Originally Posted by sailorchic34

Upnor is good stuff and that is a good system. A tad pricey for the tool for the typical home or boat owner. For the pro, it's works. And that is what is important.

The Pex crimper is $27.00 on Amazon. This is the one I purchased and it works great. Glad I have one on the boat for any future expansion of the system.

I also installed a Manabloc manifold so that I could manage each run independently. I ran a home run to each fixture/appliance. I did not daisy chain from one to another. In case I ever have to trouble shoot the system it will make it much simpler.

IMHO, nothing beats PEX on a boat.

http://www.amazon.com/Pex-Cinch-Clam...ds=pex+crimper

[SVNeko]

Most production boats use PEX nowadays. Don't know which fittings, tho.

[jeepbluetj]

Originally Posted by Mikado

The Pex crimper is $27.00 on Amazon. This is the one I purchased and it works great. Glad I have one on the boat for any future expansion of the system.


http://www.amazon.com/Pex-Cinch-Clam...ds=pex+crimper

That tool is for the SS cinch type of pex fittings. Sailorchic mentioned the uponor fittings.

I particularly like the ProPex (wisbro/uponor) type of fittings. You need to get em mail order or from a supply house, and the tool is around $700 or so.

But they're far better than the crimp style. On a boat, I may consider the plastic fittings over the brass ones.

These are different than the crimp fittings, you can only use PEX-A type of tubing, but once you see one done you'll understand why it's a great system.

I've re-plumbed my entire house with this stuff (copper in contact with concrete was really stupid). Once you figure it out (about 10 min for anybody that can turn a wrench) this stuff is fast fast to install.

For a DIY on a marine project, I'd always recommend ProPex IF ya can borrow the tool. The other methods are ok too, the Uponor is just better. For a DIY homeowner, it may be worth buying the tool.


Video of what I'm talking about:

https://www.youtube.com/watch?v=ngr0-631kFo

(Nope, I don't work for them. I do software)