Our 2003 H356 will spend this winter laid up in the water. I bought a big zinc guppy to hang over the side for electrolytic protection. However, the cable from the guppy to the alligator clip is not long enough to go from the prop shaft to some place over the side. The prop shaft is my first choice of where to attach the guppy's cable. I have two choices and I am not sure which is best or even workable. (1) I can splice an extra few feet of wire into the guppy cable so that I can go from the prop shaft or engine ground to a good location over the side. (2) I can attach the alligator clip to something that is grounded to the engine and here is my question. Is the standing rigging or anything else on deck electrically bonded to the engine/shaft so that it can substitute for attaching to the engine/shaft?
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minimize resistance
Steve To be most effective, the anode should be either as close to the metal you want to protect or connected thereto with little or no resistance. Your best option is to extend the anode cable directly to the prop shaft with an unbroken wire. Baring that option, make sure you have a good, soldered connection extending the cable from the anode to shaft. You can, as many do, connect the anode to a chainplate but only if the connection from it to the shaft has minimal or no resistance. This last option is often a poor substitute particularly when you don't know the path resistance to the shaft or that it is poor in which case the only thing you've achieved is a false sense of security. Also, an alligator clip isn't a good choice - better to use a SS hose clamp which has a far greater surface (i.e., contact) area.
Steve To be most effective, the anode should be either as close to the metal you want to protect or connected thereto with little or no resistance. Your best option is to extend the anode cable directly to the prop shaft with an unbroken wire. Baring that option, make sure you have a good, soldered connection extending the cable from the anode to shaft. You can, as many do, connect the anode to a chainplate but only if the connection from it to the shaft has minimal or no resistance. This last option is often a poor substitute particularly when you don't know the path resistance to the shaft or that it is poor in which case the only thing you've achieved is a false sense of security. Also, an alligator clip isn't a good choice - better to use a SS hose clamp which has a far greater surface (i.e., contact) area.
Thanks Don - sounds like you have some experience in this area so here comes another related question. The cable on the zinc guppy is silver in color - I think that it may be tinned copper. Must I use the same kind of cable for the extension or is untinned copper OK? Thanks again.
guppy cable is steel!
Steve, the guppy cable is steel-on our 356 we ran a 10ga tinned copper (marine wire) line from the engine block back to the aft bulkhead and mounted a terminal post there-in the locker over the exhaust hose. we feed the guppy cable out the stern locker and secure it to the swim handholds with tie wraps. the end of the cable is cut off and a crimp on eye installed to attach to the post. At the engine end, you can bolt the cut-off alligator clip to the block and cklamp it on the shaft for an additional connection. Our marina is so bad electrically (lots of powerboats) we use the guppy all year and it's completely gone at the end of the summer season so we attach a new one every year.
Steve, the guppy cable is steel-on our 356 we ran a 10ga tinned copper (marine wire) line from the engine block back to the aft bulkhead and mounted a terminal post there-in the locker over the exhaust hose. we feed the guppy cable out the stern locker and secure it to the swim handholds with tie wraps. the end of the cable is cut off and a crimp on eye installed to attach to the post. At the engine end, you can bolt the cut-off alligator clip to the block and cklamp it on the shaft for an additional connection. Our marina is so bad electrically (lots of powerboats) we use the guppy all year and it's completely gone at the end of the summer season so we attach a new one every year.
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