HOW BIG?

Aug 11, 2011
858
O'day 30 313 Georgetown MD
I see a lot of different size raw water strainers available. How big does it have to be? The thruhull with strainer to catch the tree limbs is 3/4. Anyone know what size inline filter I should use.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Good question. Most in line strainers have screens in them. Which strainers (picture please) are you thinking about.

For example the Groco
54435F-p.jpg
Groco, Bronze Raw Water Strainers with Monel Baskets, ARG Series.
  • Select by Port Size = Size
  • Thread is NPT
  • Monel strainer basket with 2 mm holes
  • O-Rings on all mating surfaces
  • Screw-on cap makes for easy maintenance
  • One-Piece Molded Sight Glass Eliminates Tie Rods and Gaskets
  • Non-Metallic Cap Magnifies Internal Viewing
  • Improved Drain Plug
  • Mounting hardware and brackets included
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Strainers on the outside are a bad idea, unless you like to dive. Much better to trap weeds on inside where you can remove them than stuck to the outside where you can’t.

The size internal rew water strainer depends on where the intake is and how weeds are in your area. I have one much smaller than @jssailem( he may be over compensating for personal reasons), never filled it to the point it overheated the engine.

Les
 
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Gunni

.
Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
I see a lot of different size raw water strainers available. How big does it have to be? The thruhull with strainer to catch the tree limbs is 3/4. Anyone know what size inline filter I should use.
You would size the raw water strainer to that same 3/4" pipe size. Manufacturers then size the strainer filter media dimensions to meet pipe size flow rates.
 
Jan 22, 2008
50
Oday 30 Stamford CT
twodzusfittings... I have a Groco ARG-750 3/4" similar to the picture in tssailem's post mounted on the wood panel between the port side of the engine and the space under the galley sink.
 
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Aug 11, 2011
858
O'day 30 313 Georgetown MD
I'm having a weird phenomena happen. Brand new strainer with 3/4 barbes. Raw water to pump through the new strainer will not pull water up to heat exchanger. Remove strainer and have hose hooked up to pump, direct from raw water thru hull, no issue. Water comes through in plenty. What the dickens is going on?
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I'm having a weird phenomena happen. Brand new strainer with 3/4 barbes. Raw water to pump through the new strainer will not pull water up to heat exchanger. Remove strainer and have hose hooked up to pump, direct from raw water thru hull, no issue. Water comes through in plenty. What the dickens is going on?
Missing gasket, allowing air leak on the strainer?
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
How high above the pump is the strainer?? You may need to rebuild Raw water pump to increase lift (flatten cover plate).

But +1 on air leak on strainer.
 

Gunni

.
Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Make sure the strainer drain plug is installed and tight.
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
Another vote for some kind of air leak in the strainer preventing effective suction.
 
Mar 26, 2011
3,402
Corsair F-24 MK I Deale, MD
I bought into the "strainer should be on the inside" thing until I sucked up several fish that jammed in the 90s before the strainer and one at the strainer inlet. Removing the hoses from the barbs to clean is not at all easy. I only need to clean the external strainers ~ twice per season, which is fine. I would rather dive in 32F water with a dry suit than repeat that.

AC intake is the big problem for me, since it is the only one that runs while the boat is not moving.
 

Ward H

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Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Raw Water Strainers have an inlet and outlet, usually marked with an arrow indicating water flow. Maybe check that it is not plumbed backwards?
Did you use teflon plumbers tape on the threads of the fittings?
 
Aug 11, 2011
858
O'day 30 313 Georgetown MD
Thread sealer on. Direction correct, cap on with o ring correct. I'm thinking that with the filter being large and the pump can only move a small amount of air each full turn, that it takes a lot longer than I am giving it to create a vacuum that will allow water to be sucked up from the thruhull. I'm going to try again.
 
Mar 26, 2011
3,402
Corsair F-24 MK I Deale, MD
Thread sealer on. Direction correct, cap on with o ring correct. I'm thinking that with the filter being large and the pump can only move a small amount of air each full turn, that it takes a lot longer than I am giving it to create a vacuum that will allow water to be sucked up from the thruhull. I'm going to try again.
Does the line rise steadily, from through hull, pas the strainer, to pump, with no high loops? Is the pump below the water line? If these things are true, the line will flood and priming will be immediate. If there are high loops... that can be trouble. Take a very close look at the rise.
 
Aug 11, 2011
858
O'day 30 313 Georgetown MD
The pump is above the water line. Its on the engine. There is a steady rise in the hose to the filter from the thru hull and continues to the pump. Its the same with the hose that I put in place when I remove the filter.
 
Jan 27, 2008
3,045
ODay 35 Beaufort, NC
Fill the strainer with water and pour water in the hoses with the seasick closed. This should eliminate almost all the air in the system to help prime the pump.
 
Aug 11, 2011
858
O'day 30 313 Georgetown MD
Well I'll be darned! Removed the garden hose which was temporary, hooked up my original set up, strainer and all. Works like a champ! Well that topic is closed. Don't worry. I'm sure there will be more. Thanks all of those that commented, help or just laughed at/with me!
 
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