Wedge Intake Strainers Revist

[DCMY #92]

Previous threads make it pretty clear that those with external wedge intake strainers are happy with them. What's not so clear is a preference for SS versus bronze perforated screens. I'm going to install wedge strainers on my engine, and AC intakes. I'm concerned about how long SS screens last.

I'd appreciate comments and testimonials.

 

[GJH]

I don't think that is such a swell idea for the AC intakes. They are used when the boat is sitting still, so nothing to wash weeds etc off them. It works on the mains because almost by definition there is water movement past the strainer.

 

[Boatsb]

I run AC when cruising BUT I think there is no need for the AC to have a wedge. neither the AC nor the genny really need one in most cases.

 

[spcoolin]

Wrong thinking guys...

The A/C pump is centrifugal & needs a scoop or wedge to keep the water being siphoned out of it by the effect of the hull moving thru the water at speeds of over around 7-8 knots...

Over the years I have answered many of those calls where the customer says the A/C quits when I get underway or it looses prime and won't cool when I get back in the slip...

I've even had a few argue that they know the scoop is there...Only to find when the diver or they go down them selves, that it is missing or turned around facing aft...

Steve~

 

[GJH]

Steve, I took the OP to mean putting in a mesh wedge external strainer in lieu of internal basket strainers. I should have been clearer. I have a "scoop", per se, on mine, feeding an internal basket type.

 

[spcoolin]

Thats fine George...And to be truthful...I'm not that fond of the external wedge strainers for a/c...I'm just saying that a/c needs either a scoop or wedge forward facing to keep the a/c pump from loosing prime when underway.

Ocean Yachts has used the external strainer wedges for years, and while they eliminate basket & globe cleaning...They cannot be easily cleared if they do clog.

I myself would prefer to have a larger than needed scoop & thru-hull, that any grass or such could easily pass thru and be caught in a basket that can be emptied or cleaned from inside the boat.

Going over the side at night or in other dangerous moorings is something that most prefer not to have to do.

Steve~

 

[REBrueckner]

spcoolin

"The A/C pump is centrifugal & needs a scoop or wedge to keep the water being siphoned out."

absolutely a good idea.



"external strainer wedges .....cannot be easily cleared if they do clog.

I myself would prefer to have a larger than needed scoop & thru-hull, that any grass or such could easily pass thru and be caught in a basket that can be emptied or cleaned from inside the boat."

That's one good apprach....and is the essential tradoff....take your pick

I prefer pinhole type strainers outside, not slot type strainers, because I have never found any grass stuck in my pinhole strainers. I guess there is no guarantee that stuff will float away if the boat is not underway, so it's not ideal either.

In Nantucket, guys who run their gennys most of the time often have to clear interior strainers daily....lots of eel grass floating around that gets sucked in. Several friends who have that arrangement as recommened by spcoolin just check periodically during the day to see if there is grass gathering in the genny strainer.

Maybe a raw water flow meter in such arrangements would be a good idea.....

 

[Angela]

I have the bronze pinhole scoops on my mains and no seastrainers in the engine room. I went under the boat last week to check my intakes and running gear. The pinhole mesh was surprising clean and I only knocked off a couple of small "volcano" looking crusties since I was down there anyway. It as painted with bottom paint when they were installed and it's all still there, nearly 18 months later.

I did not change out the original scoop on the AC for the reasons spcoolin mentioned. I am very happy with my set up.

 

[jim rosenthal]

Bronze screens are much better- they resist marine growth. Stainless ones don't, in my experience, and will foul much more easily and faster. Stick to bronze.

 

[Angela]

Bronze screens are much better- they resist marine growth. Stainless ones don't, in my experience, and will foul much more easily and faster. Stick to bronze.

I agree, given what I see on my AC SS basket. I use toilet boil cleaner on that to get the crud off when I clean the strainer. For something that's not easy to access, i.e. the screens under the hull vs. a basket inside the boat, go with bronze or don't do it at all. And use bottom paint on them, making sure you, or the yard, doesn't clog the holes when painting them.

 

[DCMY #92]

Thanks for the comments. Just what I needed. I'll stay with conventional scoops on the A/C and use bronze perf wedges on the mains.