Zinc's on Small OB

[pscrabber59]

Happy Hoildays to all.
I bought a few outboards(93'Merc. 3.3hp, 83' Evinrude 7.5hp) this past summer and plan to use both in salt-water cond.
My questions are, do i need to install those little zincs bars on the cav. plate? if so is just usually 2 small bolts&zinc bar and your finished?
Thanks for all&any advice

 

[Home Cookin']

Re: Zinc's on Small OB

I'm no expert but it strikes me that since your small outboards aren't going to be in the water except while being used you don't need to protect them. Further, they aren't hooked up to anything electric so there's no stray current. The electrolysis problem that the zincs sacrifice occurs with combinations of salt water, metals in antifouling paint, metals in motors grounded inthe water, and electricity in the motors (and sometimes stray electrical currents in the water). I put them on my metal electric trim tabs that stay underwater (salt) and the zincs really take a hit.

For example I once accidentally left the key on overnight; the 70 HP motor was down in high salt water and it's an old motor with mysterious electrical issues. next day it was right fuzzy from some kinds of magical chrystals.

Same should apply to trailer boats that aren't exposed that long, especially if the bottom isn't painted. I'd just stick with how the motor was made.

 

[steelespike]

Re: Zinc's on Small OB

Of course a careful flushing a wipe down is understood after a workout.

 

[pscrabber59]

Re: Zinc's on Small OB

Thanks guys for the info. I was able to buy a small little zinc anode from a marine store i go to for $3 bucks but the guy who own's the store told me not worry about the zinc anode because i don't have the motors in salt-water all the time submerged.

 

[Mi duckdown]

Re: Zinc's on Small OB

Bad info from the marine store. .02

 

[Larry3215]

Re: Zinc's on Small OB

Galvanic corrosion doesnt need a current source. Just having dissimilar metals in the water is enough. Like SS bolts and aluminum parts or even two different grades of aluminum or the motor and antifouling paint, etc.

You wont get a LOT of corrosion on each outing if there is no active current source, but its still there and it accumulates over time. The longer its in the salt water, the more damage is done.

If you have been around boats any length of time you will have seen the results.

The people who make the outboards - even the small ones - put the zincs on them for a very good reason.

If you dont mind critical parts of the motor eroding instead of a $3 zinc, then dont worry about it

 

[Texasmark]

Re: Zinc's on Small OB

I ran small OB's most of my early life. The only time I had any kind of corrosion is when the boat sat in the water with the engine down for about a week. The superficial corrosion wasn't all that bad, just something that you could see and wipe off. None of the engines had any Zinc anodes. As others have said, tilt the LU up out of the water and when you get home, flush it out with your garden hose.

Don't make a big deal out of nothing.

Mark