Raw water strainer disaster waiting to happen

[Hayden Watson]

@Project_Mayhem Here is a photo showing where it is mounted on my boat. As @Hayden Watson mentioned, the water line is a few inches below the seat. As chance would have it, it's just at the in and out ports of the strainer.

That happens to be where I mounted the fuel filter.

Mine is just outboard of the fuel pump.

Originally, my fuel pump was where your strainer is, but I moved the pump closer to the engine and used the screw holes for the pump to mount the strainer. My thinking was that I would need to access the top of the strainer to clean it out and the small hatch is far easier to open than the top of the engine cover. The Racor is inside my sound insulation, the fuel pump is on the other side of it and the strainer is just beyond that.

 

[Project_Mayhem]

Where are you putting the strainer that will require 20' of hose?

Behind the seating around the table, up against the port side hull. We measured about 17-18' for the entire length of the hose from the through hull and back to the pump inlet on the engine

It is easy to find the waterline on your boat. Get a short length of clear hose sized to your thru-hull. Install it and run it straight up. Open the thru-hull and the water will go up the tube and stop at the waterline.

The boat is on the hard

it's just at the in and out ports of the strainer.

So most of your strainer is below the waterline while the ports are at the waterline? I'm trying to get mine above to mitigate risk and make it a bit more pleasant to clean

 

[Ward H]

So most of your strainer is below the waterline while the ports are at the waterline? I'm trying to get mine above to mitigate risk and make it a bit more pleasant to clean

Yes, most of it is below the water line. I see little risk with a quality strainer like the Groco. Especially compared to the little cheap all plastic strainers that Catalina and at least one Hunter I know of, installed.

To mitigate risk of a failed hose, I religiously close all of my thru hulls.
We set the dinette are up as our bed and eventually decided to leave it set up. Of course that made it more difficult to get to the engine water intake so I moved it.
I was installing new Marelon Series OEM 93 thru hull valves anyway so I put a new one next to the galley sink drain aft of the water muffler. That solved that problem.
I also changed to 3/4" intake hose to the Groco so little stuff would get to the strainer rather than clogging smaller fittings and hose.

 

[jssailem]

If I wanted to be sure about the height of the water in the boat, I would use a water level.
This is what a professional one looks like.


But you could accomplish the same results using a length of clear hose filled with water. Fille the hose full and cap the end so water does not escape. Position someone outside the boat with the hose end above the level of the water line (or bottom paint line).

Inside with the opening above the level of the water you cna move the hose about. The level of the water in the hose will reflect the level of the water marking the boat's water level from outside.

Old school but effective. Thank you Archimedes.

Water Level Basics: How to make and use one

Water levels are a great way to find a level spot on items like posts ... <p class="read-more-container"><a title="Water Level Basics: How to make and use one" class="read-more button" href="https://www.theengineeringchoice.com/what-is-water-level/#more-8109" aria-label="More on Water Level...

www.theengineeringchoice.com

 

[Tally Ho]

This looks like run of the mill heater hose if I'm not mistaken? No issues with collapsing under vacuum?

It is, and no issues.

Greg

 

[Project_Mayhem]

If I wanted to be sure about the height of the water in the boat, I would use a water level.
This is what a professional one looks like.

View attachment 228878
But you could accomplish the same results using a length of clear hose filled with water. Fille the hose full and cap the end so water does not escape. Position someone outside the boat with the hose end above the level of the water line (or bottom paint line).

Inside with the opening above the level of the water you cna move the hose about. The level of the water in the hose will reflect the level of the water marking the boat's water level from outside.

Old school but effective. Thank you Archimedes.

Water Level Basics: How to make and use one

Water levels are a great way to find a level spot on items like posts ... <p class="read-more-container"><a title="Water Level Basics: How to make and use one" class="read-more button" href="https://www.theengineeringchoice.com/what-is-water-level/#more-8109" aria-label="More on Water Level...

www.theengineeringchoice.com

I bought the boat on the hard

 

[jssailem]

I bought the boat on the hard

It would be reasonable to assume the unloaded water level is about 2 inches below the edge of the bottom paint. If you set the bottom of the strainer at the height of the bottom paint you’ll be above the water level at a reasonable level for the strainer.

 

[Hayden Watson]

It would be reasonable to assume the unloaded water level is about 2 inches below the edge of the bottom paint. If you set the bottom of the strainer at the height of the bottom paint you’ll be above the water level at a reasonable level for the strainer.

The only part that needs to be above the water line is the top so that you can remove it to clean the screen. If it is too high, you will have problems with losing prime which can cause overheating.

 

[Project_Mayhem]

I'll be mounting this as high up in the engine compartment as possible like Ward and Haydem mentioned. I need a reduction bushing for the NPT ports on the strainer. I know that sched 40 and 80 have a different wall thickness. I assume the threads differ as well?

 

[Hayden Watson]

I'll be mounting this as high up in the engine compartment as possible like Ward and Hayden mentioned. I need a reduction bushing for the NPT ports on the strainer. I know that sched 40 and 80 have a different wall thickness. I assume the threads differ as well?

No, the threads and OD are the same. The schedule determines the wall thickness, and the ID varies between the different schedules. A Sched 80 is stronger but has reduced flow area.

 

[Project_Mayhem]

No, the threads and OD are the same. The schedule determines the wall thickness, and the ID varies between the different schedules. A Sched 80 is stronger but has reduced flow area.

Thank you for the clarification!

 

[Project_Mayhem]

My friend took the measurement for the hose measurement. I took a look yesterday and discovered that the hose wraps all the way around and under the engine. It looks nice, provides better access to the front and clearance for the hoses. His estimate of 18' if we were to move the strainer further away was accurate.

Regardless, I will be keeping it in the engine compartment. Is it ill advised to put an elbow on the input side of the strainer due to the higher potential for clogs?

 

[Ward H]

You do want to consider the elbow you use.
I started out with 5/8" hose for the inlet side. The dual size hose barb, for 1/2" and 5/8" hose, had a 3/8" diameter ID. My first time out sailing after that upgrade a small clog of grass clogged that hose barb.
I then switched to 3/4" thru hull, valve, hose and a Groco "full flow" elbow", which is designed for "full flow". Haven't had an issue since. On the outlet side to the pump I still use 5/8" hose but stay away from dual size hose barbs.

 

[jssailem]

When considering a 90º elbow, follow @Ward H's advice and use a "Full Flow Elbow."

 

[Project_Mayhem]

You do want to consider the elbow you use.
I started out with 5/8" hose for the inlet side. The dual size hose barb, for 1/2" and 5/8" hose, had a 3/8" diameter ID. My first time out sailing after that upgrade a small clog of grass clogged that hose barb.
I then switched to 3/4" thru hull, valve, hose and a Groco "full flow" elbow", which is designed for "full flow". Haven't had an issue since. On the outlet side to the pump I still use 5/8" hose but stay away from dual size hose barbs.

Are you referring to the double ended "reduction" barb that's a few inches away from the water pump?

 

[Ward H]

I was answering this question.

Is it ill advised to put an elbow on the input side of the strainer due to the higher potential for clogs?

Are you referring to the double ended "reduction" barb that's a few inches away from the water pump?

No. I had bought a straight hose barb for 5/8" hose. What I got was a hose barb that you could fit a 5/8" hose or a 1/2" hose to that barb.The ID was 3/8" through the whole barb.

Haven't had a need for a reduction double barb.

 

[Project_Mayhem]

I will skip the elbow for this application. It would made for a cleaner looking install but there's plenty of room for a straight barb. Is there a "best practice" for tape vs goop to seal the threads?

I was answering this question.



No. I had bought a straight hose barb for 5/8" hose. What I got was a hose barb that you could fit a 5/8" hose or a 1/2" hose to that barb.The ID was 3/8" through the whole barb.

Haven't had a need for a reduction double barb.

I'm guessing a PO did this to mine because the line they used wasn't flexible enough to make a bend that tight. I'll add this to my to do list.

 

[Hayden Watson]

I will skip the elbow for this application. It would made for a cleaner looking install but there's plenty of room for a straight barb. Is there a "best practice" for tape vs goop to seal the threads?
...

Tape vs goop. I have had more failures with tape than with goop, especially with any composite fittings. Some recommend both. The primary function of the tape is to provide lubrication to the threads to allow them to go in farther with less friction when making the connection, but this is not such a great advantage with composite fittings because it is very easy to install them too tightly.

 

[Project_Mayhem]

Tape vs goop. I have had more failures with tape than with goop, especially with any composite fittings. Some recommend both. The primary function of the tape is to provide lubrication to the threads to allow them to go in farther with less friction when making the connection, but this is not such a great advantage with composite fittings because it is very easy to install them too tightly.

I'm leaning more towards goop as well

 

[Blitz]

I used goop and full flow bronze elbow for mine and it's been a few years with no issues.

I also set the top at the waterline. At the dock and calm, I can remove the top and clean with the thru hull open without flooding.