Raw water Skin fitting advice please

Rogershaw said:
That's what I did
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When I had one of those I drilled a hole in the grill lined up with the valve. I could then remove the cap on the strainer and rod it through if a plastic bag or weed blocked the inlet. Never used in anger and I now have a simple Blakes valve and separate strainer which is probably a better solution.
 
Hiya, no they are composite and you can epoxy them in or sika, so they essentially become a part of the hull. Permanent for the life of the boat and no maintenance or replacing needed. And with the collars become a worry of the past.
 
Lucy52 said:
Trudesign make a scoop/strainer that can be fitted over the through hull, secured by three screws. You could try without and only fit it if needed. I will find out soon, I have the scoop but am not going to fit it yet if at all. I like the idea of beeing able to poke a cane through to clear out any obstruction.
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Yes this is exactly my thoughts, it would have saved me hours and hours to just cane through. it is likened to slapping a raw veggie burger over the scoop grill and then trying to get a pathway through but even reblocks if you can shift some of it....I am decided. Straight thru end of...many thanks!
 
Rappey said:
Do you not have to change the composite ones every 5 years? A bronze one can be for life.
My friend has a jeanneau with lifting keel and his engine intake is always blocking when sat on the mud..
I always close my seacock before taking to the mud. I wonder if the water in the intake has some sort of effect of stopping the mud getting rammed right up in the pipe?
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Hiya, no they are composite and you can epoxy them in or sika, so they essentially become a part of the hull. Permanent for the life of the boat and no maintenance or replacing needed. And with the collars become a worry of the past.
 
Lucy52 said:
Trudesign make a scoop/strainer that can be fitted over the through hull, secured by three screws. You could try without and only fit it if needed. I will find out soon, I have the scoop but am not going to fit it yet if at all. I like the idea of beeing able to poke a cane through to clear out any obstruction.
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When we transited the Canal du Midi our engine inlet seacock blocked with leaves off the canal bottom countless times, I would imagine in the end the number was about 100. Without the facility to push a brazing rod down the seacock to clear it we would never have made it through.
 
Catalina36 , do you have a fresh or sea water cooled engine. Just curious.
I looked inside my heat exchanger last year only because the end cap split due to me standing on it once to often when steps are removed and probably the first time the core had seen the light of day in 37 yrs. I have a pic somewhere. It was as clean as the day it was fitted.
I'm also on the same impellor.

I Googled " lifespan of composite seacocks" could not find an answer ?
Did find a few things saying every 5 years, but nothing to substantiate the statements.
Seems Marlow have had problems with snapping handles.
Valve needed to be operated every month to prevent seizure .
I think the issues are now sorted.
I read a yacht magazine article about trudesign and they froze it, boiled it and blowtorched it but could not get it to set alight.
Yes I would now contemplate one if I have to change a bronze seacock.
The "hanging" test seems pointless. So you can pull on the thread with a force of 500 lbs ? The hose is hardly going to pull on the thread/fitting.
The side on impact appears to be their only weak point but if there is nothing in same locker to hit it then it won't be a problem
 
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Rappey said:
Catalina36 , do you have a fresh or sea water cooled engine. Just curious.
I looked inside my heat exchanger last year only because the end cap split due to me standing on it once to often when steps are removed and probably the first time the core had seen the light of day in 37 yrs. I have a pic somewhere. It was as clean as the day it was fitted.
I'm also on the same impellor.

I Googled " lifespan of composite seacocks" could not find an answer ?
Did find a few things saying every 5 years, but nothing to substantiate the statements.
Seems Marlow have had problems with snapping handles.
Valve needed to be operated every month to prevent seizure .
I think the issues are now sorted.
I read a yacht magazine article about trudesign and they froze it, boiled it and blowtorched it but could not get it to set alight.
Yes I would now contemplate one if I have to change a bronze seacock.
The "hanging" test seems pointless. So you can pull on the thread with a force of 500 lbs ? The hose is hardly going to pull on the thread/fitting.
The side on impact appears to be their only weak point but if there is nothing in same locker to hit it then it won't be a problem
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Sorry its volvo penta closed water cooled md2020 with a seawater cooling system Exhaust system — Freshwater cooled exhaust manifold and seawater cooled exhaust elbow Cooling system — Freshwater cooling system governed by thermostat — Tubular heat exchanger with integral expansion tank — Coolant system prepared for hot water outlet fittings — Easily accessible sea water pump and impeller
http://www.plaisance-pratique.com/IMG/pdf/md2020.pdf
 
We have had composite Marelon seacocks for 25 years or so. They are exceedingly good. Nothing to service and if an o ring seal starts to drip then easily changed. Cannot corrode. Fire safe. Strong and easily pulled apart. The old bronze ones are much more trouble. Ezr brass should not be allowed aboard.
 
NickCharman said:
We have had composite Marelon seacocks for 25 years or so. They are exceedingly good. Nothing to service and if an o ring seal starts to drip then easily changed. Cannot corrode. Fire safe. Strong and easily pulled apart. The old bronze ones are much more trouble. Ezr brass should not be allowed aboard.
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DZR. Why not? They have been around since 1985 in the plumbing industry, at least 10 years in yachts. Nothing in life is totally reliable but DZR seems to last very well.
 
Rappey said:
Catalina36 , do you have a fresh or sea water cooled engine. Just curious.
I looked inside my heat exchanger last year only because the end cap split due to me standing on it once to often when steps are removed and probably the first time the core had seen the light of day in 37 yrs. I have a pic somewhere. It was as clean as the day it was fitted.
I'm also on the same impellor.

I Googled " lifespan of composite seacocks" could not find an answer ?
Did find a few things saying every 5 years, but nothing to substantiate the statements.
Seems Marlow have had problems with snapping handles.
Valve needed to be operated every month to prevent seizure .
I think the issues are now sorted.
I read a yacht magazine article about trudesign and they froze it, boiled it and blowtorched it but could not get it to set alight.
Yes I would now contemplate one if I have to change a bronze seacock.
The "hanging" test seems pointless. So you can pull on the thread with a force of 500 lbs ? The hose is hardly going to pull on the thread/fitting.
The side on impact appears to be their only weak point but if there is nothing in same locker to hit it then it won't be a problem
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It's a Beta 35, sea-water cooled through a heat exchanger so the engine itself is fresh-water cooled. The flushing is to clean the sea-water side of the exchanger and the exhaust injection elbow. The exchanger anode lasts far longer than previously which tells me that ordinarily there would be potential corrosion going on in there.

On seacocks, Catalina fit composite ones as standard. The ones on my boat were there when I bought it 15 years ago, when it was 10 years old. I've never had one break or seize. I have seen it suggested that they could burn but given that they're below the waterline, if you've got fire down there a leaky seacock would be the least of your worries. The plastic hose would burn off a metal seacock and leave it wide open anyway.
 
AndyL said:
Just wondering where you heard that?
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Its one of those things where if you hear enough people say it you think it must be true?
Add a few youtube sailing chanel vids where they do have a serious issues starting with the handle snapping off then water coming through and no way of stopping it and it makes it more believable.
EU regs saying seacocks only have to be good for 5 years and allowing "brass" has to be the worst though.
This thread has made me warm to the plastic ones ;)

Thanks for the reply Catalina36. I was asking as thats quite some system you have fitted.
 
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Electrolysis can be devastating on one boat but an identical one can have no sacrificial anodes and remain totally unscathed..
Luck of the draw?
I have no anodes in my heat exchanger and no deposits after 37 years.
Other boats have terrible corrosion and blockages. Could the speed of the passing seawater in the heat exchanger have any impact on the outcome?
 
Rappey said:
. Could the speed of the passing seawater in the heat exchanger have any impact on the outcome?
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Yes it does but this usually applies only to copper alloys. Copper nickel has great resistance to seawater corrosion but is eroded at higher velocities. Aluminium brass tubes are used for higher velocities in heat exchangers. Not sure whether the velocities in our smaller units are sufficient for erosion to be a problem. My stainless steel heat exchanger seems to be fit and well after 20 years.
 
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