Frsh water limescale

[PGD]

Hi all have the boat in fresh water for two years at a time then lift out and clean / repaint etc etc.

Found limescale all over my new outdrive - very confused.

Only thought limescale came out of the water either when it was heated over 85 degrees - eg kettle, or through evaporation ie getting a surface wet that then drys out.

So can't fathom why an outdrive which is under water gets covered in it.

Never had the problem with my old 270 drive.

Any ideas????

Peter

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[VicS]

Two thoughts come to mind.

You have an excessive level of cathodic protection.

It is caused by electrolysis due to stray current arising from within the boat or via shore power connection or from cathodic protection installed in the marina. (A build up of calcium carbonate occurs on stuctures with cathodic protection in the vicinity of the anodes).

Just a couple of ideas to start the discussion. But are you sure it's limescale

<hr width=100% size=1><font color=purple>Ne te confundant illegitimi.</font color=purple><P ID="edit"><FONT SIZE=-1>Edited by VicS on 11/06/2004 23:28 (server time).</FONT></P>

 

[boater4life]

The chalky white film means the casing of the stern drive is so hot it is boiling off the water that is splashed onto it while you're cruising or plunged into cool water when your boat comes off plane. Your stern drive is probably operating at 250 degrees. Image how thin the oil must be and how soft the internal components are at that temp! Motor vehicles don't even operate that hot.

Commercial content removed

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 13/06/2004 00:46 (server time).</FONT></P>

 

[BrendanS]

used to get limescale all around the waterline when I was based on thames, not just on outdrive. It's just evaporation of water with heavy calcium content over a period of time, and doesn't need a large amount of heat. Doesn't explain your particular problem though - and can't see how the promotion of outdrive shower as proposed by another poster is going to keep an outdrive which is underwater any cooler?

<hr width=100% size=1>Catapultam habeo. Nisi pecuniam omnem mihi dabris, ad caput tuum saxum immane mittam.

 

[PGD]

sorry mate but that's a load of rubish IMHO, cos on the Thames you're only allowed to do 4 or 5 ktns - so please explain that one /forums/images/icons/wink.gif

Peter

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[PGD]

I think that VicS has a good and valid point to make as all the boats around me are connected to the 240 v, I was for a year so this make more sence at present.

Peter

<hr width=100% size=1>Who gives the best service? tell us <A target="_blank" HREF=http://www.mssa.org.uk>Marine Service Standards Assistance</A><P ID="edit"><FONT SIZE=-1>Edited by PGD on 12/06/2004 22:26 (server time).</FONT></P>

 

[boatless]

Touting again Todd? Won't you learn?

<hr width=100% size=1>my opinion is complete rubbish, probably.

 

[PGD]

Hi read your Bio - so you're in Greece which part? have visited many parts and would love to move out thre with the boat.

Any advice ?

Peter



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[boatless]

Checked my bio - not very carefully! Last time I looked out of the window I was still in Dorking... wait, I'll check.. nope still there.

But yes, pm for as much info as you want. Love Greece, every time I get out there and have unpacked the bags, got the kids to bed and have the first Gin and Tonic, I still giggle and wonder why none of my friends do it?

<hr width=100% size=1>my opinion is complete rubbish, probably.