sea strainer

I have a universal 5432 and am installing a sea water strainer for the engine. I have one which has a 50 or 60 micron screen. Is this too tight of a weave? Is there a recommended size for our engine? What have others done? Any input is appreciated as usual.
Thanks,

Straining for a Solution

We installed a bronze Groco ARG series 3/4" strainer about 20 years ago. Still working fine. I clean it out several times while out cruising to get the sea weed bits out. Occasional leaves here in home (fresh) water.
The boat did not come with a strainer. I never really considered the 'mesh size' but figured that the manufacturer knew what they were doing, in the case of Groco.
The SS basket still looks near-new.

https://www.groco.net/products/raw-water-strainers/basket-strainer/arg-series

Here is a site link. In a couple decades the price has 'bout doubled from what I recall paying, but I consider it a really good addition to the engine cooling system.

Trivia: a friend of mine at the YC has twice removed tiny fish from his -- one was still swimming around and was escorted back to the river!

There is a picture of ours in my blog.
http://www.ericsonyachts.org/infoexchange/entry.php?140-Coupler-Shaft-Seal-and-Antifreeze

We uses the follwing

Forespar, Marelon 1-1/2" Raw Water Strainer, MF810
Seems to work.

Mine is like Loren's. Basically a stainless basket to stop weed or obvious particles.

But this is a deep water area with little sand, mud, jellyfish....

Off-hand I would think a 50 micron mesh would be useful for something like a watermaker, but overkill for engine cooling. But if you get sufficient flow through it with your pump, why not?

My boat had no strainer at all. When it was new, there was some kind of screen outside the through-hull but that was long gone. I added a very inexpensive plastic unit that was probably intended for a wash-down pump. It worked, but wasn't very durable - after cleaning it a few times the screen wouldn't properly seal again. Later, I upgraded to a Groco filter when the budget allowed.

Raw Water Strainer

We have a old Wilcox Crittenden interior strainer with a big mesh that has always done fine. For years we vacation cruised Casco Bay ME. At very high tides huge patches of seaweed would block our motor transits. The internal strainer would do its job and clog with seaweed twice a day. We added a Perko exterior thru hull strainer that had a big surface area screen. Suction was well distributed by the big screen. That never clogged but a sailboat racer would not like the drag scheme. We took the Perko off when a diver hull cleaner knocked it loose. No problems without having to transit big seaweed patches. FWIW it is a good idea to check the gasket on your internal strainer inspection port at least once a year. If it can suck air it will cut down on the cooling water flow.
Pat O'Connell
1981 E28+Universal 5411

I also have one like Loren's. It works fine in Lake Michigan. Easy to inspect and easy to clean out quickly. But if you don't open it often or put proper lubricant on the O-ring at the cap, it can be tough to open.
Mike Jacker