Raw Water Sea Strainers

[Freestyle]

After 2 full days of seriously looking for a Sport Fish for a friend I have seen a bunch of engine rooms.

All but the Bertram and Cabo did not have Sea Strainers on the main engines. The sales people told me no one does that anymore becasue the strainer on the outside takes care of the crap. Sounds great if it really works. Where do I get these miracle outside strainers?

Interestingly, the generators and a/c systems allhad conventional looking basket strainers.

Bruce

 

[Genesis]

Yeah, funny how that works..... its good enough for the mains but not the AC system or generator.... ever ask why?

Main engine sea strainers are big and expensive, and to get the flow you need you usually must upsize the rest of the intake plumbing. That's why they're not found on new boats most of the time.....

 

[SKYCHENEY]

I don't necessarily agree with this thinking, but here is why they supposedly do it this way: The AC and the Gen can run for extended periods of time with the boat stationary. The mains usually don't run that long while the boat is not moving and the don't need full flow at idle. So, when you ARE moving, the "stuff" gets swept away from the outside strainers, plus you have the ram effect while moving too because of the scoops.

Like I said, still prefer inside strainers on all raw water intakes.

 

[lisaann]

the supplier i used is bossler and sweezey www.propfixer.com talk to phil he is the owner and knows how to size the southbay (external) strainers for engine size
mark

 

[spartonboat1]

Interesting "belief" that the mains don't suck up junk. However, I am getting a lot of green "be-leafs", because my mains sea strainers need at least two cleanings a season (in MI that's kinda July-Aug ) but I moor in a large river, where there is much leaves, water aquatica, etc. If I had my way, I would go to the twin sea strainers that can be switched out on the move with engines running or at least without pulling the occluded strainer.

OK, so they don't have'm, but I prefer'em.

 

[SKYCHENEY]

The belief is that the mains DO suck up junk but that with the external strainers, the junk is wisked away once the boat gets up to speed. I don't know if this is actually true, but that is the theory behind the external strainer.

 

[Genesis]

The crap I find in my strainers and gear coolers says that theory is F.O.S.

The next "small" restriction is the EXHAUST SHOWERHEAD, and cleaning THOSE out would require dismounting the exhaust collector. You are NOT going to do that 100nm offshore. No way, no how.

 

[Nick]

Ditto!

I have stuff in the gear cooler and the shower head even with internal and external strainers. Maybe I have thought about it backwards! Eliminate the strainers altogether and no more fouling?

I doubt it!!

 

[Akyla]

I got to agree with the Pooh-Bah on this one.

The internal strainers are a must have for me. Had a boat once that didn't have any on the engines and it was a giant PIA. Ever try to clean the grass out of your cooler while the boat is pitching on the waves and you are burning your hands? Once I installed the strainers the builder should have, no more problems.

I have seen only one external strainer that was worth anything as far as keeping small debris out. Jim has them on his boat - they have a removable perforated metal screen with holes as small as the filter baskets in my Grocos. They seem to work for him.

 

[Traveler 45C]

I’m still trying to decide which way to go, inside strainers or outside screens. There are good arguments to both sides of the issue.

I’ve got the intake screens on all of my intakes, not just the mains and they have never gotten plugged up, and the A/C gets the most use in the slip. A Capt once told me tales of his adventures offshore, trolling through fields of floating seaweed and never a clog. And if they did clog, all he would have to do to clear it is shut down and the clogging material would float away.

 

[Liquid Asset]

I purchased the Groco Perforated hull strainers. I will be installing them this weekend while we are out and i will be removing the internal baskets. There are tons of little holes in the front of these strainers that are the same size as the holes in the baskets in my boat. If it will get through these hull strainers, then it would have probably gotten through my basket too.

I am going to keep the basket for a while to see what i think, but my bet is that I will like them. We shall see.

My A/C is going to keep a strainer since it run unattended quite often. I have not made a decision on what to do about the genset yet. I can not remember what the pick up looks like on the bottom of the hull. All I remeber was that it is wedge shaped. I may leave the strainer off the genset too.

I figure, worst case, I put the strainers back on and I have some nice pickups on the bottom of the boat.

 

[34Hatt]

the supplier i used is bossler and sweezey www.propfixer.com talk to phil he is the owner and knows how to size the southbay (external) strainers for engine size
mark

These are also what I use they are the best we have been using these up here in the N.E for as long as I can remember. NEVER HAD A PROBLEM growing up this what my dad had on the boat 1000s of miles of cruising never clog and never had the Internals. Still have not put the 2" Internals I have on ebay any offers
I also use them on ever Intake and thats it no fuss no muss

 

[Mike36c]

Pat, I have the Groco wedges with the small perforated holes on my mains and I have NEVER seen anything in the aftercoolers (first stop for debris) or anywhere else including the exhaust showerheads. The engine temps don't go up one degree when trolling thick weed lines or Bahamian turtle grass. It's a dirt simple design that works. However, I have not tried this set up on A/C's or gennys (I have traditional strainers on my A/C and Genny), it seems normal boat movement keeps the main screens clear but a week on the hook or at a trashed up Bahamain marina would surely foul a screen only A/C or genny. Install them on your mains and enjoy! Mike

 

[TedZ]

Hydromatic makes a self cleaning strainer...has mascerating blades like a garbage disposal. Probably cost more than the boat but if you have a serious problem i'm led to believe these will solve it and pass nothing that would get trapped anywhere.

I have not used them or seen them used...just an FYI

Ted

 

[Traveler 45C]

I’m interested in seeing these. Do you have a link for us?

 

[REBrueckner]

It seems that many years ago most external hull strainers were the slotted type..that is maybe 1/8" wide open slots. I think the "perforated" external strainers, those with many small round holes instead of slots, are a newer design, and a superior one. Older slotted external hull strainers DO let junk inside, eel grass, for example, can get sucked in when underway. The new perforated holes are so small virtually nothing gets either lodged or sucked in. A minor disadvantage is that several coats of bottom paint may partially block the holes so they must be cleaned with an ice pick or drill every so often. An upside of the hole design is that little light gets inside so mussels and barnacles don't seem to grow inside the strainer. The newest design, holes in a removable stainless steel plate, permits easy removal of the plate via several studs and easy inspection access inside the strainer.
I agree that with the newer hole design on external strainers, internal sea strainers are no longer required. One less maintenance job and a failure point eliminated, especially in freezing environments.

 

[Traveler 45C]

I found it: http://www.westmarine.com/webapp/wcs/stores/servlet/product/10001/-1/10001/7269/10001/217/70/11

I have these on the boat now: http://www.westmarine.com/webapp/wcs/stores/servlet/product/10001/-1/10001/7253/10001/217/70/11

 

[REBrueckner]

That Westmarine photo seems to negate my comment about letting less light thru. My Hatteras original all bronze strainers have smaller holes with more solid space between holes. I like the removeable plate for access...