Replacing the Raw Water Strainer

Improving our Raw Water Strainer

The current Raw Water Strainer setup

Our Raw Water Strainer is located in the cabinet below the Head Sink ( Arrowed in this pic ) 

To clear the raw water thru hull, we have to shut the valve, remove the two hose clamps that secure the short piece of hose to the Thru Hull, push a rod or sewage snake into the pipe where the hose was connected, grasp around the top of that pipe, open the Thru Hull to minimize the water ingress. Now I can push the rod or snake all the way down and out of the Thru Hull, clearing out anything blocking the inlet. Most often it's a piece of flotsam that got sucked up into the pipe.

Once cleared, next it's pull the snake out and close the Thru Hull valve, reconnect the pipe and secure with the two hose clamps. 

I would normally shine a flashlight through the strainer glass ( plastic ) to ensure the strainer is clear, if not, I would remove the glass and clean out the strainer.

Restart the engine and check for water discharge with the exhaust.

The New Raw Water Strainer

SEAFLO Raw Cooling Water Intake Basket Strainer is available on Amazon. Cost is $29. This is the one that has an Inlet and Outlet that fits 1/2", 5/8" & 3/4" Hose.

The benefit of this style of fitting is that the cop is easily removed and the Strainer is secured to the bulkhead rather than being held in place by the position of the hoses as in the existing strainer.

The idea is to mount the new strainer so that the open strainer has the natural water level just below the top.

That way, when the lid is removed, the water in the strainer does not overflow the strainer body.

Additionally, the body will be mounted so that it the intake hose connection is directly above the Thru Hull. Now to clear the pipe and Thru Hull, it should be just a case of open the lid and pull the strainer basked up and out, then run the snake down the inlet pipe and Thru Hull to clear the pipe. While at it the Strainer could be cleaned. Then just close the lid. All done.

Although there would be no need to shut off the Thru Hull valve, we make it a normal process to close all Thru Hulls whenever we get to the dock. The valves are frequently operated to ensure they stay useable.

The new Strainer does require the output hose to be connected differently from the existing strainer. So we have purchased 9' of Silicone Hose which is more flexible than the existing hose. It may require an Elbow joint to avoid the hose blocking access to the Depth, Speed and Water temperature transducer which we remove every time we get back to the dock.

 

Here's the schematic. As always, I'll use embossed hose clamps rather than the perforated type and there will be two clamps on each hose connection as this is sea water - ie. there's lots of it to flow in if a hose comes off of it's connection, but as mentioned, we close all of the thru hulls every time we get to the dock.

Estimated time for this project:

• Remove old Hose to the Thru Hull  5mins
• Remove old Hose to the Raw Water pump 20mins
• Put a clear hose on the Thru Hull and open the valve to find the Water Level and Mark on the bulkhead. 10mins
• Mount the new Strainer - Two screws into the bulkhead. 15mins
• Measure & Cut the hose from the thru hull to the strainer ( 5/8" hose connection ) 5mins
• Connect hose to the Raw Water Pump and thread it around the engine into the Strainer area under the sink and connect to the Elbow. 30mins
• Connect from the Elbow to the outlet of the strainer. 10mins
• Open the through hull - check for leaks.

That's about one and a half hours.  

Project Materials

• Seaflow Strainer  $20
• 5/8" Hose $74
• 12 x Hose Clamps $12

That totals to about $105.

That's my job this morning, it's too windy to work on the replacement of the standing rigging today.

I'll update this post with pics of the completed project.