From recent posts, you can tell I'm on thinkin about the engine water
cooling system.

RECAP: I've got an inboard that is raw water cooled. The pump is a gear
type. The thru-hull is a scoop shape with somewhat of a strainer on it. It
looks basically like this...only bronze.

http://www.forespar.com/catalog/plumbing/scoop.htm

Question: Is this enough to keep junk like plastic bags from clogging my
water intake, or do I need something else?

My guess is that this is enough; that most things will either be big enough
to
just pass on by and anything small enough to get in will be chopped up
by the meshed bronze gears in the pump.

Thanks,
Gary

That should be fine. Do you have a gear type?? or does is it a flexible
impeller pump?. If it is a true positive displacement gear type, then small
solids could jam it. However I have never seen a true gear type raw water
pump. Maybe some larger boats (ships?) may use them but I don't know about
that. So if it is a "gear" pump you may need some thing else but If it is
the normal flexilble impeller raw water pump , you should be fine with what
you have as the size of solids passing that type strainer intake should pass
the pump too.

--
Ron White
My boatbuilding website is:
www.concentric.net/~knotreel

Thanks Ron.

Yes, this is a true gear pump. A picture is here, on the second page:
http://tinyurl.com/spsv

Wow! what a project I didn't know that we were dealing with and antique. I
was doubtful that you had a gear pump but one picture ( actually 93) is
worth 93,000 words.Apparently your pump is a gear drive as well as being a
gear pump. I would hate to guess what one like that would cost today. I
guess the flexible impeller pump was still on the drawing board back then.
Well, as far as a strainer, it might be a two edged sword. If it got clogged
and water flow was too little to cool the engine, and there were no alarms
well that could be bad. If it were me, I might tend to trust the rather
beefy gear drive pump to just chew up anything that is light enough to
float. Things that would likely damage that pump are more likely on the
bottom? But then in the final analysis I don't know what you should do.
Either way there are risks. The boats I am familiar with that have sea
strainers are mostly offshore boats and have high temp alarms and often run
in sea grass like Sargasso. One of my old boats didn't have a sea strainer
and spun and impeller after getting fouled with grass. But I think mere
grass would be no match for your "rolling mill pump". Anyway, strainer-no
strainer, I it may depend on personal preference in this case more that the
usual considerations? Keep up the good work.
--
Ron White
My boatbuilding website is:
www.concentric.net/~knotreel

PS:
Ron, Nice site. Any photos of the work when it was in progress??

I'd sure put a strainer.

"Gary Warner" wrote in message
...
From recent posts, you can tell I'm on thinkin about the engine water
cooling system.

RECAP: I've got an inboard that is raw water cooled. The pump is a gear
type. The thru-hull is a scoop shape with somewhat of a strainer on it.
It
looks basically like this...only bronze.

http://www.forespar.com/catalog/plumbing/scoop.htm

Question: Is this enough to keep junk like plastic bags from clogging my
water intake, or do I need something else?

My guess is that this is enough; that most things will either be big
enough
to
just pass on by and anything small enough to get in will be chopped up
by the meshed bronze gears in the pump.

Thanks,
Gary

I agree with Keith. If you put a strainer on, I think you'll be surprised
by the stuff that gets caught: bird feathers, seaweed, little chunks of
wood, etc. To me it's like running a car engine without an air filter.


"Keith" wrote in message
...
I'd sure put a strainer.

"Gary Warner" wrote in message
...
From recent posts, you can tell I'm on thinkin about the engine water
cooling system.

RECAP: I've got an inboard that is raw water cooled. The pump is a gear
type. The thru-hull is a scoop shape with somewhat of a strainer on it.
It
looks basically like this...only bronze.

http://www.forespar.com/catalog/plumbing/scoop.htm

Question: Is this enough to keep junk like plastic bags from clogging my
water intake, or do I need something else?

My guess is that this is enough; that most things will either be big
enough
to
just pass on by and anything small enough to get in will be chopped up
by the meshed bronze gears in the pump.

Thanks,
Gary

Gary Warner wrote:


Question: Is this enough to keep junk like plastic bags from clogging my
water intake, or do I need something else?

It is cheap insurance and good practice to place a strainer between the
seacock and the raw water pump.

The strainers shown here by Groco are excellent for your application as
they allow visual inspection and are easily cleaned:

http://www.depcopump.com/catalog106/PAGE56.PDF

Rick

On Sun, 02 Nov 2003 19:17:00 GMT, Rick
wrote:
It is cheap insurance and good practice to place a strainer between the
seacock and the raw water pump.

The strainers shown here by Groco are excellent for your application as
they allow visual inspection and are easily cleaned:

http://www.depcopump.com/catalog106/PAGE56.PDF

================================================== =====

I agree with the inboard strainer recommendations. My boat has Perko
strainers. They work well and are easy to clean.

http://www.cgedwards.com/Perko/pko21.html

Strainer is NICE TO HAVE with a raw water cooled engine. There are some tight
cooling water passages in the engine. IMO, it's essential with FWC to keep
stuff out of the heat exchanger(s). Even with positive displacement gear pump
some debris ground up by the pump will get past but much less than with a
flexible impeller type pump.

For me it would depend upon only one thing. Do you have space in the bilge to
install and SERVICE a strainer? You'll want to be certain you have sufficient
room to operate the seacock if you opt for a strainer.

Butch