Shaft Brush....or not??

[rpell1@msn.com]

Hi all,

My 30 Catalina sits in a slip where electrolysis is a very bad problem. A friend suggested a copper Shaft Brush to help reduce zinc deterioration.

Has anyone had any experience with this? If so, and it helps, where can I get one?

Thanks all and Happy Sailing,

 

[Don S/V ILLusion]

My view is this isn't a solution to your problem but here is a link nevertheless:

http://www.defender.com/product.jsp?path=-1|344|301236|69608|303332&id=1037168

My reason is simply that you are not fixing the problem but rather are transferring it to another area - typically the heat exchanger where the problem becomes more insidious and expensive to repair.

The better q you might ask is what is causing the problem and how do you fix it.

 

[BobM]

Buy a zinc fish until you figure it out.

 

[rpell1@msn.com]

Other than moving the boat from the area......

....are there other solutions? I would appreciate an education. Being familiar with how you guys are "packed-in" up in Newport, we are in the same boat, (bad play on words), here in Sheepshead Bay. So, anything you can contribute would help.

Thanks and Happy Sailing,

Ralph

My view is this isn't a solution to your problem but here is a link nevertheless:

http://www.defender.com/product.jsp?path=-1|344|301236|69608|303332&id=1037168

My reason is simply that you are not fixing the problem but rather are transferring it to another area - typically the heat exchanger where the problem becomes more insidious and expensive to repair.

The better q you might ask is what is causing the problem and how do you fix it.

 

[Graysailor]

The shaft brush is usually used in conjunction with a bonding system. You must connect all the thru hulls with 8 gauge copper wire ending at the shaft brush. Typically you then continue the wire to a large zinc that has been installed on the outside of your hull. This larger zinc then takes most if not all of the electrolysis. The boat must be hauled out to install the zinc. A zinc fish may help temporarily. Be certain that where you attach the fish is "hot". Take an ohm meter and check various stainless areas above the decks. Example the life line rails, a stanchion, a shroud. If you get a reading on the ohm meter attach one end of the zinc fish there and drop the zinc into the water.

 

[Hermit Scott]

"Bonding is not good in a "hot" marina." Calder
The reason why is, the sea water is the electrolyte, the two metal pieces even though they are the same metal will have different potentials because of their distance apart in the water and from the source of the electricity flowing in the water. To make a battery out of them all you need is a bonding wire to complete the circuit.
Electrically isolated props are better in a hot marina.