Transition Polybutylene water lines

[Scott Mc]

Came across this thought it might help whenTransition Polybutylene, shark bite fittings with the grey cap work.

https://www.youtube.com/watch?v=1pwBLq6ortQ

[Uncle_Bob]

Newer Bayliners have Sea Tech (Aqualock) pipes and fittings: https://www.watts.com/aqualock-marine

[Bacon]

Wow, that's an awesome find. I have had to do transitions with multiple fittings going from poly to brass flare or nppt, like 3 inches of couplings to get from one to the other. Those shark bites are going to make it so much easier!

[brad4550]

Scott Mc
The plumbing throughout older Bayliners is known as “Quest”at least that’s what I remember will those Shark Bites work?.are they “polybutylene”.

[Scott Mc]

Scott Mc
The plumbing throughout older Bayliners is known as “Quest”at least that’s what I remember will those Shark Bites work?.are they “polybutylene”.

As far as I know the lines are polybutylene and the quest fitting are known to be not great and can leak, if the shark bite fitting will work will be a good way to upgrade to make repairs

[MidnightSun]

There is no rocket science here just some misunderstanding. Most boat fitting including my Carver and all 3 of my past Bayliners have 12mm OD water lines which happen to be the same size as Polybutylene. This does not mean you have PolyB on board however older Bayliners may. The newer stuff used is still 12mm although it may be white or blue or red and would be composed of the same materials as Pex which is Polyethylene just like the Sea Tech/Aqualock mentioned above which is 12mm and not compatible with 1/2" Pex unless using a conversion fitting. IMHO just get the right stuff and do not convert.

Some boat manufactures have elected to go with 1/2" Pex and here lies the incompatibility/confusion as Pex is 1/2" OD (12.54mm) and the more standard boat stuff is 12mm. Unfortunately looking at color is not going to determine what you have. A measurement with a caliper will tell you though.

Hope that clears things up.

[MidnightSun]

OOOPs, the above post for 1/2" converted to MM should read 12.7

[Woodsea]

All the plastic domestic water piping on our 2000 boat is 1/2”. I freely use 1/2” pex tubing when modifying. The existing tubing fits nicely into shark bite fittings.

[MidnightSun]

All the plastic domestic water piping on our 2000 boat is 1/2”. I freely use 1/2” pex tubing when modifying. The existing tubing fits nicely into shark bite fittings.

Are you sure? 1/2" fittings are used on 12mm and may seem to fit however the proper seal is just not there. If they were truly compatible then Sharkbite would not offer the conversion fittings. On the other hand if you were to try 12mm fittings on 1/2" Pex they will not go on.

[Woodsea]

Hans,
Our boat is a 2000 47. Here is my experience. I’ve not measured the oem stuff. Our boat does not have the gray tubing but looks slightly opaque clear. I’ve bought pex brand tubing and put it into the oem compression/flare fittings and they seal. I’ve pushed the oem tubing into new shark bite type fittings and they seem to seal. So far over 9 years they have worked great.

[builderdude]

Hmmm, shark bite fittings make the seal on the exterior (OD of the pipe/tubing). 1/2” copper pipe is .5” ID & .625 OD, 1/2” pex is .485 ID & ..625 OD. I never measured the grey tubing on the boat so I’m not sure of its OD dimension, I just purchased those fittings from my local RV supply outfit.
Maybe I’ll go measure the OD of the boat tubing 🤔
Edit: Just measured my ‘93 model year. It is fitted with Nibco tubing at 1/2” ID and .625 OD.
Shark bite fittings will work for this tubing.

[Seahawk II]

They make Shark Bites that are specifically for the transition from Grey poly to PEX. Shark bites is just one manufacturer and the term "shark bite" has become generic just like Q-tips. Some manufacturers claim you don't need a special connector to transition. I've had good luck using PEX to PEX with poly lines but those were easily accessible. I just replaced a leaking poly hose section in my park model with PEX and the special poly to PEX connectors. In this case the floor will be closed back up so I don't want to take a chance. They cost about $8 a connector.