John and Anne on Bali Hai <annejohn@...>
This cooler is the first one in the hose carrying all the cooling sea
water to the engine etc.and is thus the first thing to collect any
trash that gets past the main sea water filter.Note that this cooler
is small and has small bypass cooling tubes.
I had a problem with my engine and called in a mechanic who
disconnected the hose from the cooler and it was nearly totally
blocked with bits of weed.He opened the main filter which was full
with a grass type weed and cleared all of this out but in the process
found that there was no gasket at the bottom of the filter housing so
he cut out a new gasket to stop detritus from bypassing the
filter.This gasket had been missing from original delivery or
So far so good but there is a design fault with the filter in that
it is basically an open tube so that when removed it does not take
all the rubbish with it thus leaving some floating in the sea water
in the housing. Some of this can be removed by hand but to clear it
all it is necessary to open the sea cock to make the housing overflow
carrying the trash with it. It is then necessary to wash all the sea
water off with fresh water from the general area to avoid corrosion.
A quite different probem is the birth of new barnacles etc. If the
sea water system is left standing in the right conditions for any
period of time, for example, over winter. These will develop and
perhaps later be washed up against the cooler and will also start to
grow in the impellor housing with, if they grow and adhere
enough,will damage the impellor.
The answer to that would be to turn off the sea water cock and put a
fresh water hose in the filter housing then starting the engine to
flush out all the sea water from the entire cooling system although I
imagine that anything that grows in the hot part of the circuit would
be cooked and be flushed away in due course.
Envying those in the Caribbean, Anne & John, SM319