Sacrificial Zinc's (When Are they Needed?)

[HappyOurs1]

I recently Purchased a1964 Evinrude Sweet 16 that hasn't been in water for 10+ years.
During rebuilding the Water Pump, etc... I removed the Sacrificial Zinc's from the Motor.

They appeared to have deteriorated quite a bit. My Question is:

Should I put them back on, buy new ones, or since my boat will be a day boat and back on the trailer that day or the next.... In & out of both fresh & Saltwater?

If in Saltwater.... I will rinse boat & flush motor after each use.

Are Zinc's required or highly suggested for such use?

 

[robert graham]

Re: Sacrificial Zinc's (When Are they Needed?)

Clean the zinc's with a wire brush and re-install, so they'll corrode instead of other parts of your motor. Rinse and flush motor after each use anyway. Outboards need all the help they can get to prevent corrosion. I spray some parts of my motor with white lithium Grease to protect from saltwater. Good Luck!

 

[Chris1956]

Re: Sacrificial Zinc's (When Are they Needed?)

Since you are going ot trailer the boat, zinc anodes are not necessary. I would reinstall the ones you have and call it a day.

 

[SolingSailor]

Re: Sacrificial Zinc's (When Are they Needed?)

With all respect to the previous replies,
Electrolytic corrosion is cumulative. Get new zincs.

 

[Chris1956]

Re: Sacrificial Zinc's (When Are they Needed?)

Soling, I have had trailered boats. Do you know how long it will take a zinc anode to disolve if the boat lives on the trailer? I had a set on my trailered boat for 18 years, and they showed no signs of erosion....

 

[colding]

Re: Sacrificial Zinc's (When Are they Needed?)

I installed a brand new zinc on the foot of my motor about two months ago. I've had the boat in the water maybe 6 times in that span. My boat lives on a trailer and I can already see the corrosion on the new zinc. Can't imagine what it would be eating away at inside my motor without it.

 

[Scott Danforth]

Re: Sacrificial Zinc's (When Are they Needed?)

I recently Purchased a1964 Evinrude Sweet 16 that hasn't been in water for 10+ years.
During rebuilding the Water Pump, etc... I removed the Sacrificial Zinc's from the Motor.

They appeared to have deteriorated quite a bit. My Question is:

Should I put them back on, buy new ones, or since my boat will be a day boat and back on the trailer that day or the next.... In & out of both fresh & Saltwater?

If in Saltwater.... I will rinse boat & flush motor after each use.

Are Zinc's required or highly suggested for such use?

Sacrificial Zincs are required, or your motor becomes sacrificial - ESPECIALLY IN SALT WATER. you choose.

 

[Chris1956]

Re: Sacrificial Zinc's (When Are they Needed?)

Colding, You may want to check for current leakage from your boat or from others around you. You should not have corrosion on zinc anode on a trailered boat. Do you have an I/O with a impressed current anode/cathode system?

Stray current in the water can accelerate the erosion of the anodes many times.

 

[colding]

Re: Sacrificial Zinc's (When Are they Needed?)

I have owned many boats over the years, all of which have been trailered. Every single one of them have shown signs of corrosion on their zincs. They are never around other boats, except passing on the waterways. Even seems to happen on my small 15HP Mariner that is only used in freshwater. The one I just changed is a 2005 90HP Johnson 2-stroke. It didn't have to be replaced because it was too corroded, I broke it when removing it to repaint the foot, but you could tell it was eroding.

 

[HappyOurs1]

Re: Sacrificial Zinc's (When Are they Needed?)

Thanks Guys, Greatly appreciated. My Motor had a total of 3 Zinc's on it. One Giant say 1lb and two small, the two smaller ones broke when trying to take them off so I threw them out. They were on the wings of the leg closer to the prop, the big one is in the front above the gear box. Should I replace the two smaller ones too or will the single large one be okay?

 

[Scott Danforth]

Re: Sacrificial Zinc's (When Are they Needed?)

I would replace all of them, especially if your in salt water.

 

[robert graham]

Re: Sacrificial Zinc's (When Are they Needed?)

Sacrificial zinc anodes are really a "no-brainer" type item....why would anyone not use them?

 

[dingbat]

Re: Sacrificial Zinc's (When Are they Needed?)

You should not have corrosion on zinc anode on a trailered boat.

The corrosion of zinc in water is largely controlled by the impurities present in the water. Naturally occurring waters contains nitrogen, oxygen, CO2, and other gases, as well as salts of calcium, magnesium, iron, and manganese. Seawater contains many of these salts in addition to its high NaCl content.

The corrosion resistance of a zinc coating in water depends on its initial ability to form a protective layer by reacting with the environment. The scale-forming ability of water depends principally on three factors: the hydrogen ion concentration (pH value), the total calcium content and the total alkalinity. If the pH value is below that at which the water would be in equilibrium with calcium carbonate (CaCO3), the water will tend to dissolve rather then to deposit scale. Waters with high content of free CO2 also tend to be aggressive toward zinc.

 

[Scott Danforth]

Re: Sacrificial Zinc's (When Are they Needed?)

anything in water that will make it conduct electricity will be the need for sacrificial anodes. the fact that your motor has aluminum, brass, steel, stainless.....just add ANY mineral to the water and you have a battery.

 

[nwcove]

Re: Sacrificial Zinc's (When Are they Needed?)

Since you are going ot trailer the boat, zinc anodes are not necessary. I would reinstall the ones you have and call it a day.

not necessary? with all do respect, they are an important part! why let your motor corrode beyond the point of being servicable for the cost of the zinc plates???? and they do help in the off season!

 

[Chris1956]

Re: Sacrificial Zinc's (When Are they Needed?)

Cove and others, I keep my outboard boat in the saltwater at my dock. The transom clamp has a bar shaped zinc anode, which has been on it for at least 5 years. It is still serviceable, although I need to scrape the barnacles off of it often. The motor shows no sign of erosion.
The boat I had before (SeaRay I/O with MerCathod system), went thru two sets of zincs a season. Clearly there are differing amounts of electrical activity in the same water, depending on the boat.

if you think erosion is a problem for a trailered boat, go with lots of zincs. My experience does not support that.