I found two black plastic masses (for lack of a better term) bolted to the bottom of my gimbals where anodes can be bolted (IE under the hydraulic ram manifold). I was then told they are the cathodes for the MerCathode system and not to remove them, but I'm having other thoughts.

I have a pair (one on each engine) MerCathode (Black box) that are circa 1996. I've read multiple posts regarding the procedure for testing and how when tested they typically aren't putting out spec. current to fully protect against corrosion anyway. I've seen owners run two of them in parallel (on each engine) to gain adequate protection. I also read of testing the system one day and three days later they are dead.

For a boat not stored in the water, I would maybe have it in 72 hrs. at once if I wet slip it to stay on overnight when away from home, would it be more practical to remove the MerCathode's on the bottom of each gimbal and go with anode protection? I figure the stagnant anode protection is at least known to be "working" consistently without the worries associated with keeping the MerCathodes, which for all I know can be dead already.

Your thoughts and experiences are greatly appreciated !
Keith

If the mercathode system actually works, I'd hate to see how bad corrosion can get without it lol.

what if it's a trailer queen, and always washed rinsed, flushed
or closer to the truth, how hard is it to hook up correctly ?

Do you ever have the boat in the water, slipped, overnight, etc., WITH the shorepower attached? This is when the Mercathode is most important.

https://www.amazon.com/dp/B001QUXB2W...=I5VMKYMKM4AFX

This will help....

Agree, this is the point for the Mercathode

And Merc has testing procedure's to make sure it is working correctly as it was intended for. Also keep Anodes in check and replacing with new beforehand as well.

If you plug into shore power I would consider adding a galvanic isolator. Even though I rack store my boat I added one to mine for those long weekends I am plugged in at marinas. http://www.pkys.com/FAQ/galvanic.htm

I will, maybe a handful of times a year.

Yes I have read it, and it requires a $125 lead for my multi tester and the boat to sit in stagnant water for 8 hrs. Before testing. Then I may find I need to add another MerCathode box to the currently installed units in order to have proper protection which changes from slip to slip anyway. Or that mine are already kaput altogether being they're 20 yrs. old.

So what I'm trying to determine is, will replacing the MerCathodes with anodes provide the same protection with less headaches and at much less cost? After all new gamble anodes are ~$45/pr.

That's the next goodie on the horizon!

Anodes will assist in giving more material to sacrifice, but does not do the same job as the mercathode.

I have one of the Merc probes and its a piece of wire that has been platinum coated around a small nylon stick. You could probably get close if you silver plated a 18AWG wire, but not exact due to differences in properties