Anodes Question

[Mac of Cygnet]

5 hours ago, Alan de Enfield said:

Because of all the metal fittings :

 

I have a GRP boat with :

11 bronze sea-cocks / hull openings below the water line.

2x steel shafts

2x Bronze propellers

2x stern glands

2x steel P-Brackets

 

Without anodes the sea-cocks, and propellers would become very brittle and shatter.

 

 

Yes, I know that, but your quote specifically refers to the anodes being attached to the fibreglass hull.  As there is no metal connection between the vunerable metal parts and the anodes,  do they still give protection? 

[Tony Brooks]

6 minutes ago, Mac of Cygnet said:

 

Yes, I know that, but your quote specifically refers to the anodes being attached to the fibreglass hull.  As there is no metal connection between the vunerable metal parts and the anodes,  do they still give protection? 

You normally bolt thorough the hull and provide internal bonding to all metal parts that need protecting OR fit suitable anodes directly on the parts to be protected.

[Alan de Enfield]

6 minutes ago, Mac of Cygnet said:

 

Yes, I know that, but your quote specifically refers to the anodes being attached to the fibreglass hull.  As there is no metal connection between the vunerable metal parts and the anodes,  do they still give protection? 

They need to be bonded.

 

Generally engine sea-cocks and exhaust fittings are bonded but other are not always (toilet in / out, deck wash etc etc)

Prop shafts, props and rudders are bonded.

 

The problems are really where these are dissimilar metals so a bronze prop going onto a steel shaft, etc etc.

 

Prop shafts can be bonded internally using one of these :

 

 

[WotEver]

55 minutes ago, Peter009 said:

What do you use ?

I no longer have a boat but when I did then an Airlink IT (isolation transformer). See here:

http://www.smartgauge.co.uk/galv_tran.html

[Peter009]

1 hour ago, WotEver said:

I no longer have a boat but when I did then an Airlink IT (isolation transformer). See here:

http://www.smartgauge.co.uk/galv_tran.html

Interesting reading thanks for that will have to think of the options