PEX tubing for deck washdown?

Merlin Clark · Feb 14, 2013

I don't know how Pex failures compare to PVC in house plumbing but had recently heard of problems with the fittings: http://failures.wikispaces.com/PEX+Plumbing+Failures
I'd thought about running it through my attic but after hearing this decided to go PVC.
For boat plumbing I've always used reinforced tygon tubing.

navigator97 · Feb 14, 2013

I heard in recent discussions that, while there were a lot of problems with the fittings and resultant leaks, that those problems have been resolved and that the PEX line and fittings are now quite good.

jismay · Feb 14, 2013

I have used pex tubing and a mixture of compression and Shark-Bite http://www.sharkbite.com push-on fittings to redo much of the plumbing in an old RV. I can't think why use inside a boat would be much different. Just be aware that most PEX is NOT UV stable, so it needs to be protected from even indirect sun as much as possible.

alexco38 · Feb 14, 2013

Don't use push on fitting

I helped a friend with a 2004 Hunter replaced all his metric sized PEX tubing and push on fittings with North America sized PEX with crimped brass fittings. North America PEX is double walled.

The push-on fitting leaks wherever there is repeated movement, like a boat!

Crimp on is the best. I have them on my boat and home now. The crimping tool is not cheap but works really well. It makes the plastic bite into the brass fitting to form a permanent bond. You can't take it off.

Merlin Clark · Feb 14, 2013

Good to hear I was wrong. It sounds like a very handy product/system.

TomY · Feb 14, 2013

The only drawback I see to PEX tubing,...

py26129 said:
On my to do list this spring is the installation of a deck washdown system. the plan is to have a Jabsco fitting on the bow and one on the stern, eliminating the need for a 30' hose.

This will require a fairly long run of hose from the washdown pump to the Jabsco fittings, inside the boat.

Is there any reason not to go with PEX tubing vs. reinforced plastic hose? PEX is cheap, pressure rated and available at Home Depot or equivalent. Seems like it's almost too easy.

Thanks in advance

Matt

,...is it's a stiff tubing. I use it in home applications but you have to be aware of it's turning radius. If your installation has few sharp turns, it would be great. If you have to install a few fittings, I doubt it's worth the savings. I prefer the crimp type fittings on PEX, they're fool proof. It's usually preferred by tradesmen to run just like wiring, source to outlet, no fittings. Then they make end connections. If you can do that, you're all set.

On all the boat plumbing I've done, I can't think of where it would be as handy to install as regular reinforced marine tubing.

Maine Sail · Feb 14, 2013

alexco38 said:
I helped a friend with a 2004 Hunter replaced all his metric sized PEX tubing and push on fittings with North America sized PEX with crimped brass fittings. North America PEX is double walled.

The push-on fitting leaks wherever there is repeated movement, like a boat!

Crimp on is the best. I have them on my boat and home now. The crimping tool is not cheap but works really well. It makes the plastic bite into the brass fitting to form a permanent bond. You can't take it off.

I suspect he had metric pipe and US fittings or vice verse. The push on fittings by Watts are excellent. The Shark Bites from Cash Acme are good too but being brass they turn green and look like crap on a boat.

I use the Watts 35 series polysulfone fittings exclusively and have never, ever had a single leak. I disconnect and reconnect mine every fall for tank draining and winterizing etc.. I have a few hundred of the Watts 35 series fittings out there on customers boats and not one single leak... They are rated for 250 PSI @ 75F and 100 PSI at 180F. These certifications are well beyond any temps or pressures you'd see on a boat for domestic water. Vibrations on sailboats should not affect these fittings in the least.

I also have PEX crimp tools and expanders from when I was rep for a radiant tube line of vapor barrier PEX tube for hydronic heating systems.. I still much prefer the Watts series 35's for use on a boat.

Most of the quality made push-on fittings are certified for "hidden" or under ground joints meaning joints can be made in-walls or underground without access plates. They also meet the applicable plumbing codes for land (we don't have any for boats).. Hidden fittings are not an easy certification to get for residential or commercial plumbing PEX or not.. The push on fittings that have the proper approvals have been thoroughly vetted.

Something was not right in your friends installation or they used low budget non-plumbing certified fittings..

seadaddler · Feb 14, 2013

Plastic

I am not sure what they call it but I used the same or similar as Hunter used in their boats but got all the tubing from ace hardware and or HD and did what you want with a fitting in bow anchor locker and at the stern for wash down but I use salt water for anchor wash and at the stern.
Nick

alexco38 · Feb 14, 2013

It was the white colored push on fitting that goes on red or blue pex hose. Almost half of them leak. I found that the o-ring was on the outside of the hose. And if there is any scratch. It slowly leak. If you disconnect them for winterization, may be incorrectly, it leak.

Maine ship may be right. Metric and NA almost the same size.

A few of them seems ok, may be different batch. The bronze fitting seems much better.

We dont pull the fitting to winterize now. Has T fittings for that.

Steve Dion · Feb 14, 2013

Nick:

I would guess that the material was Qest/Quest. I belive that is what Hunter used in our '85 H'31. No issues with it either.

It was NOT a good product for homes/mobile homes, they had a class action suit because of all of the damage that it cased.

I think the issue had to do with water pressure and possible issues with clorine in the water.

seadaddler · Feb 15, 2013

My setup

It's about 6 years now since I added my wash down for my anchor locker hose connection for washing the anchor and also add the same hose connection at the stern and has come in very handy for cleaning off dirt and fish blood all with salt water,the wash down pump is at bottom of my companion steps where I have all my thru hulls and taped into the head thru hull. and have on and off switch under the nav station.
I had come across a roll of heavy plastic hose and went to either Ace or HD for push on connections and found the hose very easy to run through out the boat from under the bow anchor locker and also to the stern and have not had any leaks or pressure problems.
Pretty sure got the wash down pump system here on this forum and everything came with it a fused on and off switch which I like.
Nicks

rgranger · Feb 15, 2013

I have pex all through my house. Buy the crimper or better yet... find someone who will lend you one. The hose is easy to cut, bend around corners and connect.

Chris Burti · Feb 15, 2013

I used PEX ten years ago for our washdown system and have had no leaks or other issues inside the vessel. I used a stainless hose bib fitting in the anchor well and fabricated a slide out rocket launcher to house the hose coil. The only issue that I have had is that we do not have to winterize in our location, so I keep forgetting to drain the washdown hose which has sufficient exposure to allow it to freeze. I also located the hose bib at the bottom of the locker in order to make for a tidy installation. As a result, I end up with a few pinoles at the bib end each Spring and then have to drag out both anchors and rodes in order to disconnect the hose so that I can cut off about six inches of hose.

Had I to do it again, I would locate the bib at the top of the locker so I wouldn't be so tempted to procrastinate in draining the hose.

Skip Gundlach · Feb 15, 2013

I have used flexible, but hardwalled (won't collapse under suction, if that's what you're doing) 3/8" plastic tubing, and hand-tighten (but equipped for a wrench application as well), compression-type fittings from Lowes or Home Depot for all the plumbing, either new or replacement, that we have done aboard.

I also did the fore and aft washdowns, and made rocket launchers for coily hose out of 4" PVC, with a cap. I ripped a 2" or so opening on one side so that the hose would not have to come out the top when being used; I just lift the hose and take a turn in the coil; it goes right back in.

I have NO problems with leaks if I just tighten the fitting. Tees, joints, Ys, all are fine. This is on a blaster pump, 45# pressure, with a pringle-can (1-liter) accumulator.

Back to the pipe and fittings, however, that's also what we use for our fresh water pressure lines. No problem...

L8R

Skip