BONDING

[akopac]

<div>Some time ago one of our group suggested visiting the web site
yachtsurveyonline.com. If you haven't visited this site yet,
you should. There are some very insightful and straightforward
articles on boat and engine maintenance that I have found
invaluable. In the engine maintenance article the author
explains bonding of various pumps and thru-hulls to prevent
galvanic corrosion. After reading this I checked my 383 and
discovered none of the thru-hulls are bonded. When the boat was
hauled 10 months ago for it's survey all the thru-hulls appeard
fine. Although, I have been having extreme difficulty in
keeping a shower pump operating. I've had both diaphram and
impeller types. The author indicates that if a metal bodied
pump is not bonded it is prone to galvanic corrosion and
inoperability. I have gone through three shower pumps in ten
months, so maybe bonding is the answer to this problem. Any
thoughts on the lack of thru-hull bonding on our boats?Eric
</div>

 

[cavale]

Eric
It doesn't sound right that bonding or not bonding thru-hulls has anything to do with the failure of your shower pumps. The shower pump, like all the rest of the pumps on board, is connected to it's thru-hull with plastic or rubber hose which should negate any electrolis or galvanic action. Your problem might be on the suction side of the pump. The piping under the shower unit that feeds the shower pump is notorious for getting clogged and is a bear to get at to clean out. Once clean, install a strainer in the suction line and give it some attention during the season. It will trap the human hair that can kill a pump.

 

[capnrichard]

My M384 had bonding to all the truhulls when I bought it but I don't know if it was original or not.

 

[balthazor]

There is lots of debate about bonding everything, as I understand it. Some say yes, some say no. As with most other subjects, Practical Sailor has written extensively about this over the many years I have read the magazine. My sense is that in a glass boat, as long as all the through hulls are the same material (preferably bronze), and you keep zincs in the appropriate places, like back near the shaft, there is no reason to bond. If the through hulls are solid, that proves the point, I should think. My 382 is not bonded through out, she is 20 years old, and all the through hulls seem fine. I intend to check gudgeons and pindels this year and hope and trust they are also fine.