raw water corrosion

[Alrob]

It has just occurred to me that seeing as how raw water cooling is very bad for our engines then why the hell do they make them !!!!!

It leaves me with the conundrum whether or not to take the boat out this winter or leave it lying on its berth full of salt water

/forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

 

[npf1]

have you thought about flushing the raw water system with antifreeze whilst the boat is still in the water?

 

[Alrob]

yes thought about it - but dont know how to !!

 

[npf1]

assuming it's an inboard engine without saildrive or outdrives,

1/ close off the raw water intake seacock,
2/ remove the hose from above seacock
3/ mix up a coupe of buckets of antifreeze and water
4/ place hose tail from 2/ above into a bucket
5/ start engine on tickover which will then suck the mixture from the bucket 1. At the same time empty contents of bucket 2 into bucket 1. Depending on the size of your engine this might take a few seconds or a bit longer.
6/ Stop engine just before bucket is empty.
7/ Connect hose back to seacock.

A useful modification is to permantly rig a diverter valve after the seacock so the above procedure can be quickly done without all the fagging around of removing the hose from the seacock.

Hope that makes sense!

Oh ... and if you have outdrives, I guess you'll just have to wait until someone else responds to your post. I know [--word removed--] all about them!

 

[Alrob]

I am afraid your barking up the wrong tree - its a Bravo 3

the practicalities of getting a/freeze in without sinking the boat have been discussed many times before on this forum

 

[stelican]

Bravo 3 is a sterndrive not an engine

 

[Fire99]

Personally if its gonna just sit in the water over winter and not be used id pull her out and put her on the hard.. If you flush the engine with antifreeze, its gonna have little benefit as the 1st time you use the boat it will all go back in the sea again.

The reason for raw water cooling is pretty much down to cost IMO. My boat has a VP V8 Petrol and back in the day was a cheap install with simple (and fairly cheap) mechanicals. So when things did start to get eaten away they just replace them.

There is no functional benefit i know of raw water cooling other than simplicity

 

[tony345]

Why take your boat out over the winter - where is it written that you can't use your boat just because its a bit chilly.

Leave the boat in - use it and wrap up warm.

Given that you have a raw water system, its not going to corrode any faster during the winter than it does in the summer

Why waste money on antifreeze - its salt water so its not likely to feeze

 

[PCUK]

Anti-freeze also protects against corrosion!
Remember also that leaving the boat (GRP) afloat all the time is a recipe for osmosis. It is the winter drying out period ashore that slows the process.

 

[Bajansailor]

I wouldnt worry too much about osmosis - I am assuming that Alrob's Bayliner (I wont call her a Binliner!) is not very old, hence there is a good possibility that she was built with isothalic (rather than orthothalic) resin - iso is much more 'resistant' to osmosis than ortho - and she might even have been epoxied as well.
Or she might even have been built with vinylester resin, but I doubt it - that seems to be mainly the preserve of boats at the higher end of the market (altho I hope that I am wrong!).

 

[Fire99]

I agree to use the boat all winter.... Thats what i do.. some of the best boating days have been just after christmas.

My point is that IF you dont intend to use the boat over winter then i wouldnt just leave it floating in water for months. Then it is better out the water and not being so battered by the eliments.

 

[oldgit]

"recipe for osmosis"

Think the Navy,RNLI,HMCE and other sevices should be told ASAP,they may want to put a few minesweepers/escorts/customs boat and perhaps a few lifeboats ashore for the winter.Then would contact local harbour master,the pilots can always swim out to the big stuff instead of using the Nelson.
That only leaves the steel half our local fishing/charter fleet etc to keep going during the winter cos all the Mitchells and Aquastars will be sitting up in rows on the hard. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[Alrob]

where did all this talk of osmosis come from - I thought my post was about engines - silly me

/forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif

 

[oldgit]

All boats should come with a large label attached,saying something like

"Warning ALL warranties are Null and VOID if this item if used anywhere near WATER."

 

[blueglass]

[ QUOTE ]
All boats should come with a large label attached,saying something like

"Warning ALL warranties are Null and VOID if this item if used anywhere near WATER."

[/ QUOTE ]

I once had a warranty claim for outdrive seal failure carried out by a volvo main dealer because I had "exposed the seals to a hostile environment" unquote. That would be the sea, then.