Zinc bonding system on the hull?

SanDiegoChip · #1 (**permalink**) 10-05-2009

Hi,
We are about ready to purchase a Frigoboat refer system and I was asked what type of zinc bonding system we have on our boat. Our boat is a 1978
36' sail boat. An Islander Freeport. I do not know what kind of zinc bonding system I have or how to find out. I have found nothing when Goggled. Our through hulls are all metal so how do they not corrode? I haven’t found anything in the archives either.

Thanks,
Chip

mitiempo · #2 (**permalink**) 10-06-2009

Hi
There are two sides to bonding. One side says everything metal underwater should be bonded to give every piece of metal the same electrical potential. The other side says that when you bond a through-hull that previously wasn't you are adding it to the electrical mix un-necessarily. I agree with the second opinion and have no through hulls bonded. The shaft zinc protects the propeller and shaft and the through hulls are not electrically connected to anything. This will probably start a debate and I look forward to various opinions.
Brian

wwilson · #3 (**permalink**) 10-06-2009

Chip,

I have a Frigiboat system as well. If the system is the same as mine, it uses seawater to cool the refrigerant. The seawater cooling coil contains a sacrificial zinc anode. The installer may need to know if you use a whole boat thru-hull electrical bond. My boat does not and I agree with Brian. If yours is bonded, the installer would connect it (electrically) to the others.

Wayne