Fresh water flushing made easy

[watson1987]

The prior owner showed me how he would open the sea strainer and stick a hose in to flush the seawater out of the coolant system on the D4-300 on my R-31. I never liked just having a hose sticking into the strainer, if the hose got knocked you risk running it dry, and keeping the sea cock open is a bit of a mess when you have the lid off the strainer.

I added one of these right after the sea strainer, on the line going to the impeller
https://www.groco.net/ssc-1500

Now after every trip I go through the following steps.
1. Turn off engine
2. Shut off sea-cock
3. Pop off stopper and install quick connect hose fitting
4. Open the sea-cock
5. Turn on the hose
6. Turn on the engine
7. Let it run for 2-5 minutes
8. Turn off engine
9. Turn off hose
10. Shut off sea-cock

NOTE: From my experience there isn't enough pressure from the hose to spin the impeller with the engine off and sea-cock closed, which could be dangerous as this could flood the lifting chamber on the exhaust and cause it to explode when the engine is turned back on. I've only run the hose very short periods of time with the sea-cock closed though, I always just leave it the sea-cock open while the hose is on to prevent this issue (or the marina shutting off your water mid-flush) and since fresh water is lighter than salt water you don't have to worry about mixing when you turn the hose off before you finally close it on step 10. An added bonus here is that any seaweed is forced back out of the sea-strainer through the sea-cock. When I've gone to inspect my strainer it is always completely clean.

In addition, I have a small lanyard that I keep on the sea-cock when it is open, when I close it, I take it off and clip it to the engine off battery switch. This is a reminder to myself to open the sea-cock when I turn on the battery on my next trip.

https://www.icloud.com/sharedalbum/#B14G3KxPyGrGJwc

The cheapest place I found to buy one of these is here, this fits my D4-300 2018 R31 sea strainer.
https://www.wholesalemarine.com/groco-s ... e-adapter/

Super bonus trick:
If your bilge pumps stop working, you can close your sea-cock, attach the quick connect to a small hose and stick it down in your bilge and be able to pump out a bit of water in an emergency assuming your engine still works.

 

[BB marine]

I installed the same Groco fittings in my Mainships 34 Pilot for flushing the engines. I made up a hose adapter with a ball valve that attaches to the Groco quick disconnect hose fitting. This adapter allows me to have the fresh water all attached with the valve closed and fresh water readily available in a 5 gallon bucket. The adapter with 5' of hose is placed in the 5 gallon bucket full of clean fresh water with a fixture of salt away. I have the raw water through hull open and start the engine the engine is now running and pumping water via the thru hull, I begin to open the freshwater flush using the adapter ball valve and start closing the boats thru hull When the fresh water valve is open completely open I close the boat thru hull valve . It only takes about 30 seconds to empty the 5 gallon bucket. I shut the engine down. Fill the bucket again with fresh water no salt away, start the engine again suck the bucket dry shut down leaving the though hull valve closed. The engines raw water cooling and strainer now have fresh water in them and all the saltwater critters flushed out. Note I installed my flush up stream of the strainer. The ball valve is connected to the Groco quick connect. With this 5 ' hose and ball valve it is an emergency bilge pump that I can turn on and off using the ball valve.

I would post photo's but I still can't download to my album.

 

[CaptT]

I do pretty much the same thing. I have a ball valve with a hose fitting, usually used for rain barrels, on the bottom side of a 5 gallon bucket,(https://www.amazon.com/RAINPAL-Barrel-Q ... 6750&psc=1). I attach a three foot section of 3/4"" garden hose on to it and then to the Grogco fitting. I turn off the thru hull, fill the bucket with no salt and water, start the engine and run that through. I then fill the bucket with fresh water and run the engine with a running hose in it. I run the engine until the intake catches up with the hose flow. This generally takes about 5 minutes, + or minus a couple of minutes, then I shut it down.
To save space I store the hose and extra lines in the bucket under the back seat or under the port cabinet. It really makes it easy to flush the engine before they lift it and rack store the boat.
I also put a three way, barbed on two sides with a hose attachment on the third side, on the ac intake hose and use this, with my bucket set up, to flush the ac with no salt and then fresh water as well.
The generator gets the hose in the sea strainer approach, which works well as the overflow flushes the salt water out of the bilge.

 

[Headlee]

Thanks you guys for the question and information. I just had the Groco installed about 3 weeks ago on our C28 and haven't yet used it. So, the timing of these posts couldn't have been better. Thanks again and have a great season.

Paul

 

[Newf]

Nice set-up with the Groco fitting.

I don't have a Groco fitting but for flushing on my R21-EC I just installed a Tee downstream of the seacock hose and added a 30" section of hose with a cap on the end that I leave in place permanently. When I want to flush I just unscrew the cap from the hose and stick the hose in a bucket that's fed with a garden hose. Close the seacock and fire up the engine and flush. No hose to install or remove, it's there and ready for use. Can also be used as mentioned above should the need arise to help as a bilge pump. Just unscrew the end cap and stick the hose in the bilge, throttle the seacock as need and pump away.

 

[Gwkessel]

Hi Watson,
That GROCO 1500 is the correct thread size for the basket,did the hose end fit a 2 inch hose going the pump/impeller?
Thanks,
George

 

[watson1987]

The GROCO 1500 is designed for a 1.5-inch ID hose. The thread is 1.5 inch NPT

If your basket thread and hose are 2 inch, then you'll want the bigger one
https://www.groco.net/ssc-2000