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LobeliaBlue · 04-08-2020, 10:17

Recently replaced a bunch of my plumbing, had a local guy do some of it - and he double clamped 1/2" copper to PVC.
I've had 2 of them pop off in the last 2 weeks, last one was the dishwater feed which filled up my bilge before setting off the alarm at 2am.
Good times!

What does everyone think _should_ be here? I was surprised it wasn't at least a hose barb nozzle but I'm not a plumber -
should the copper have a compression fitting? I don't like waking up to the big red bell.

CaptTom · 04-08-2020, 11:48

I saw the same connection on a boat last weekend. New water hose clamped to the cut-off end of the old copper tubing. Same result: Popped off, emptied the water tank and filled the bilge. Couldn't hear either pump (potable water or bilge) while the engine was running.

The quick fix was to "make" a barb on the copper tube with a few wraps of electrical tape, then clamp beyond that so it couldn't slide off again.

The real fix is to replace the whole thing with marine water hose or PEX, all the way up to each fixture. If you had to cheat a bit then maybe there's a tubing-to-barb fitting, possibly involving putting a flange on the end of the tubing. Some SharkBite type connectors can work on copper pipe/tubing, but if it's not a common home water system diameter, finding one to fit correctly may be an issue.

Cheechako · 04-08-2020, 12:20

Buy hose barb to flare or compression fittings? This with a NPT hose barb:
https://www.webstaurantstore.com/mid...tent=Equipment

The other thing you can do, if you have a flaring tool, is to partially flare the copper tubing. Often you can actually do this in a way to create a "bead" or bulge on the end like a barb has.
-Leave excess tubing extending out of the flare tool,
-slip a washer or nut that fits the OD of the tube end on the very end of the tube.
-when you start to flare you can make it bulge just a bit between the flare tool and the retrained end.

LobeliaBlue · 04-08-2020, 15:57

Thanks, I think a compression to hose barb is what i'm going to do.

A Flare tool is on the (long) list for the engine room tool box tho.

cheers, Lo

waterman46 · 05-08-2020, 09:14

Very simple. You can buy a union or straight fitting that is copper solder on one side and normal pipe thread on the other end. On the pipe thread you can install either a hose barb or PVC threaded fitting as needed.

Do your own work if possible. No need to have that idiot messing up your boat.

It is not hard to learn soldering of copper pipe. Plenty of on-line help if needed. Do a few practice pieces and you will be good to go. You may have to solder in a tight spot, if so then you can use sheet metal pieces backed by wet rags as heat shields.

LobeliaBlue · 05-08-2020, 12:00

Job Done. While i've sweated copper before, Id worry more about my work than a compression fitting.

Thanks everyone, have a beer. No idea why the image didn't load

Mike Banks · 05-08-2020, 17:19

There is a proper fitting for this sort of thing, but I avoid compression fittings on copper. Instead I go for the bull-nose unions used in gas fitting--a far superior seal and stronger, but you need a tool to expand and trim the copper once you have slid the b nut over the end of the pipe--and pout it on the right way around. That union connects to the plastic hose connector which fits the polythene--which IS a type of compression fitting but it uses an O ring as the main sealing device, the plastic compression bit is to stop the hose blowing off the fitting.

All of my vessel freshwater plumbing and most of the saltwater stuff was plastic--only the outer thru-hulls were navy bronze. The plastics of today are far superior to the original plastic fittings. Only the hot water pipes on my vessel were copper, and they only ever held hot fresh water.