Anode question?

[mtb55]

Ive taken my boat out in the ocean a few times and noticed that the outboard (150 merc black max) is showing signs of corrosion. I noticed the anodes were not pitting at all so I removed them to find Mercury had paint where the anode mounts. I thought anodes had to be touching bare metal to work properly??If this is the case why would Mercury have painted where the anode mounts?? Is there something I am not understanding correctly about anodes?

Thanks for any help

 

[Big Sarge]

Re: Anode question?

how many hours are on the motor?

 

[SolingSailor]

Re: Anode question?

Anodes have to be electrically connected, and nearby, to the metal they are intended to protect.

 

[tazrig]

Re: Anode question?

The bolt or screws that hold the anode on may screw or bolt into raw metal if this is the case you are fine. If not you need to sand a section where the 2 metals can touch. If you bought it new have the dealer do it for you.

 

[mtb55]

Re: Anode question?

how many hours are on the motor?

I'm not sure, the motor dose not have an hour meter. What I can say is that the previous owner who bought the boat new only used it in fresh water and claimed it was a driveway queen most of its life. When my mechanic inspected the boat he said the motor looked brand new and gave it an excellent bill of health.

 

[ricohman]

Re: Anode question?

The bolt or screws that hold the anode on may screw or bolt into raw metal if this is the case you are fine. If not you need to sand a section where the 2 metals can touch. If you bought it new have the dealer do it for you.

I was wondering about this and now I know!

 

[Thalasso]

Re: Anode question?

Check your bonding straps. There should be one from the motor to the transom mount and one from the mount to a grounding bar in the boat. All metal has to be bonded. I'll bet the anodes are OK but you have a bonding strap loose or broken. the strap will look like a braided cable. Small in size. A picture of your O/B will be better. Are you sure it is corrosion or paint coming off. Merc has a bad paint process.

 

[dingbat]

Re: Anode question?

Also define "corrosion". A trace of a white powdery substance on the surface if aluminum is normal

 

[ricohman]

Re: Anode question?

Also define "corrosion". A trace of a white powdery substance on the surface if aluminum is normal

Is this powdery stuff the anode disappearing? I've seen this stuff on the anodes after a day in the water.

 

[hungupthespikes]

Re: Anode question?

OP mtb55

What I can say is that the previous owner who bought the boat new only used it in fresh water and claimed it was a driveway queen most of its life.

Ive taken my boat out in the ocean a few times

NEVER MIX Zinc and Aluminum Anodes on the same vessel.
?Zinc Alloy Anodes = Salt water only
◦Not recommended for use in fresh water
◦Alloy is manufactured to meet or exceed US Military Specification (MIL-A-18001K)

?Aluminum Alloy Anodes = Salt or Brackish water
◦Not recommended for use in fresh water
◦Proven to last longer than zinc due to increased capacity
◦Alloy is manufactured to meet or exceed US Military Specification (MIL-A-24779(SH))

?Magnesium Alloy Anodes = Fresh water only
◦Not recommended for use in salt or brackish water
◦The only alloy proven to protect your boat in fresh water

You need to check to see what you have....
I'm a freshwater guy, the "old salts" on here came help you tons more on ocean use.
huts

 

[dingbat]

Re: Anode question?

Is this powdery stuff the anode disappearing? I've seen this stuff on the anodes after a day in the water.

The white powder is what they call "white rust". White rust is zinc hydroxide which is the reaction of zinc in contact with water. The dulling and graying of the material is zinc carbonate, zincs protective layer

 

[Thalasso]

Re: Anode question?

OP mtb55





NEVER MIX Zinc and Aluminum Anodes on the same vessel.
•Zinc Alloy Anodes = Salt water only
◦Not recommended for use in fresh water
◦Alloy is manufactured to meet or exceed US Military Specification (MIL-A-18001K)

•Aluminum Alloy Anodes = Salt or Brackish water
◦Not recommended for use in fresh water
◦Proven to last longer than zinc due to increased capacity
◦Alloy is manufactured to meet or exceed US Military Specification (MIL-A-24779(SH))

•Magnesium Alloy Anodes = Fresh water only
◦Not recommended for use in salt or brackish water
◦The only alloy proven to protect your boat in fresh water

You need to check to see what you have....
I'm a freshwater guy, the "old salts" on here came help you tons more on ocean use.
huts

This is exactly what Merc is doing with the I/O's as far as i have seen

 

[hungupthespikes]

Re: Anode question?

This is exactly what Merc is doing with the I/O's as far as i have seen

I was optimistic that would bring out some post.
per:
Anode Kit Alpha One Gen 2 for Mercruiser 888756A 1 - Performance Metals 10059A - iboats

Aluminum Mercury anode kits. Superior aluminum/indium alloy for increased protection. Exclusive Patent Pending wear indicator. Aluminum anodes provided better protection than zinc, have the longest life and are safe in any type of water.

Magnesium works for here.

Just want the OP to know there is a difference and be aware of potential problem.

Could this be causing what he is seeing???? Going from fresh to salt, with the wrong anodes, you salt guys would know.


huts

 

[limitout]

Re: Anode question?

on a related note, if your anodes are heavy with corrosive dust/frost is it advisable to clean them up and remove the lose frosting?

im just wondering if a heavy coat of frost on them insulates it a little and if cleaning them during winter storage would give better protection or just leave them be and cleaning will just remove metal from the anode unnecessarily for no benefit?

 

[achris]

Re: Anode question?

Easiest way to check anodes are mounted correctly is to take a multimeter and check that you have complete continuity (no resistance, 0Ω) between the anode and any bare metal on the engine. I usually use the end of the propshaft, or a bolt head that is unpainted... It's a very quick and easy check, and will find problems just like this one.

Chris......

 

[UncleWillie]

Re: Anode question?

Easiest way to check anodes are mounted correctly is to take a multimeter and check that you have complete continuity (no resistance, 0Ω) between the anode and any bare metal on the engine. I usually use the end of the prop-shaft, or a bolt head that is unpainted... It's a very quick and easy check, and will find problems just like this one.

Chris......

+1 on the OhmMeter.

on a related note, if your anodes are heavy with corrosive dust/frost is it advisable to clean them up and remove the lose frosting? I'm just wondering if a heavy coat of frost on them insulates it a little and if cleaning them during winter storage would give better protection or just leave them be and cleaning will just remove metal from the anode unnecessarily for no benefit?

I pull my drive and refurb it over the winter.
The anodes get a light spray in the sand blast cabinet.
They look brand new in under 5 seconds.
Nothing conducts better than fresh metal.

 

[achris]

Re: Anode question?

I pull my drive and refurb it over the winter.
The anodes get a light spray in the sand blast cabinet.
They look brand new in under 5 seconds.
Nothing conducts better than fresh metal.

:thumb:

 

[ricohman]

Re: Anode question?

+1 on the OhmMeter.



I pull my drive and refurb it over the winter.
The anodes get a light spray in the sand blast cabinet.
They look brand new in under 5 seconds.
Nothing conducts better than fresh metal.

Have to remember that. I guess pulling them off a blasting them with a light abrasive would only take a few minutes.

 

[UncleWillie]

Re: Anode question?

Have to remember that. I guess pulling them off a blasting them with a light abrasive would only take a few minutes.

That is if you include the time to pull them off.

Hold the blast gun back at least a foot and you are done in about 3 seconds. It blows off like dust!
You'll spend more time rotating the part than actually spraying.

 

[mtb55]

Re: Anode question?

Also define "corrosion". A trace of a white powdery substance on the surface if aluminum is normal

Bolts on out-drive seizing in their hole also some paint appears to be bubbling. Also my mechanic says they motor is corroding at a fast rate for the minimal amount of salt water this motor sees (not moored), approximately 48 hour of salt water use.