Wiring Zinc to Engine Block

[irwin28]

Hi folks, I know a lot if people do this and I just did myself, but does say wiring a zinc to a bolt or something on your engine block and dropping it in the water help with electrolysis? Doing this cos my zincs are going fast at this marina. I'm hauling it out anyway this spring to replace them and do a bottom job so my and my girlfriend can go cruising. Thanks!

[Intentional Drifter]

I've done it, too. I got stuck with the boat in a situation where I knew it was overdue, a diver confirmed that the old ones were 90 to 95% gone and I knew I couldn't get it hauled out for another two months, at the earliest. By the time I did get it hauled out, my saildrive zincs were totally gone, but there was no corrosion damage and everything was fine.

Besides, it can't hurt! (Unless you forget they are there before taking off.)

ID

[irwin28]

Thanks Drifter, I wired it to a bolt that is used to hold the pad eye that you use to lift the engine out with, should that be good enough?

[Sailmonkey]

I just attach ours to the negative post of the starter battery, works fine there, so the lifting eye should be more than adequate

[fstbttms]

Originally Posted by Sailmonkey

I just attach ours to the negative post of the starter battery...

What, precisely, are you protecting by doing that?

[Sailmonkey]

Well, if the negative post of the starter battery is connected to the engine block...........I'd suppose I'm protecting the engine and all the other underwater stuff hooked to it. Unless you're going to tell me the electrons don't flow through the cable as well as the one connected to the zinc guppy.

[fstbttms]

Originally Posted by Sailmonkey

Well, if the negative post of the starter battery is connected to the engine block...........I'd suppose I'm protecting the engine and all the other underwater stuff hooked to it. Unless you're going to tell me the electrons don't flow through the cable as well as the one connected to the zinc guppy.

Unless your engine is under water, you are not protecting it with this arrangement. Both the zinc and the item being protected must be submerged in an electrolyte, if the zinc is to provide protection. It is possible that you are providing some protection to your running gear, but only if there is a direct electrical connection to the zinc. A drivesaver or similar device (if you have one) negates that. Further, the greater the length of the path between the zinc and the item being protected, the less effective it is. And you have a pretty long path.

[Sailmonkey]

Originally Posted by fstbttms

Unless your engine is under water, you are not protecting it with this arrangement. Both the zinc and the item being protected must be submerged in an electrolyte, if the zinc is to provide protection. It is possible that you are providing some protection to your running gear, but only if there is a direct electrical connection to the zinc. A drivesaver or similar device (if you have one) negates that. Further, the greater the length of the path between the zinc and the item being protected, the less effective it is. And you have a pretty long path.

Thanks for the obvious
but it does work
prop to zinc, through trans, engine, neg lead <3OHM
guppy to prop approx 6"

[fstbttms]

Originally Posted by Sailmonkey

Thanks for the obvious

Sorry. Didn't realize you were a corrosion control expert.

[Sailmonkey]

Not a corrosion control expert, but I did study some corrosion engineering in school.

I know it's not perfect, but nobody said is was.

out........

[irwin28]

Fastbottoms, so If I have a 12' line between my zinc and my motor that my odds are pretty slim that I am actually protecting my engine? Well, I'm just assuming thats what you mean.

[fstbttms]

Originally Posted by irwin28

Fastbottoms, so If I have a 12' line between my zinc and my motor that my odds are pretty slim that I am actually protecting my engine? Well, I'm just assuming thats what you mean.

Zincs are mounted directly to the item being protected for a reason.

[Charlie]

Originally Posted by fstbttms

Sorry. Didn't realize you were a corrosion control expert.

I'm really amazed you get any business the way you speak to people on line. this isn't the first time I've been inclined to write a comment like this.

[fstbttms]

Originally Posted by Charlie

I'm really amazed you get any business the way you speak to people on line. this isn't the first time I've been inclined to write a comment like this.

Imagine how much sleep I lose worrying about what you think.

[Bergovoy]

come on guys, settle down...

I think the intent or reasoning is to place teh zinc as close to the item being protected as possible...if you just bond things like the way described, then the times closer to the zin will have less corrosion then the items further from the zinc..

i am not totally familiar with the technical aspect.. but from what i see on some of teh schematics there must be a reason there are 'separate' ground busses but yet they all connect...each closer to the point of use...

so, I follow that theory to the corrosion aspect... and zincs are mounted to shafts, and any exposed surfaces, and any not submerged items are connected with as large as conductor with the least amount of distance...

just my theory...

you can yell at me and tell me how dumb i am, and stop arguing with each other...