Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 

I have very minor damage to my Skeg which I bought a Skeg Gauard to cover so I don’t need to be reminded what the trailer switch in a Z272 does. However, now I’m thinking I shouldn't use it because it may increase the Galvanic corrosion.

Question 1: Should I bother with Skeg Guard or will it increase the galvanic corrosion?

Question 2: Does anyone know if the mercathode still receives power when the battery switch is off or how I can test it has power?


Here’s my water and anode configuration:

I keep the boat in a slip were the river changes from brackish to fresh. When I bought the boat I read up on the Bravo III and found they are prone to galvanic corrosion problems. Because of this I decided to add a prop anode since my Bravo III is pre-2003. I have Stainless props and used magnesium anodes last season. My anodes were consumed around 50-60% between May-October. I painted the unit myself last season but this year it was refinished since I had the boat in the shop getting other work.

Hello bblauvelt,

Question 1: Should I bother with Skeg Guard or will it increase the galvanic corrosion?

Since it is a different metal than the outdrive, yes, but the real question is how much and that is difficult to tell. Now do you need it, No, not really unless you are prone to damaging the skeg because of the area where you boat or the occasional moment of memory loss when hauling your boat onto a trailer.


Question 2: Does anyone know if the Mercathode still receives power when the battery switch is off or how I can test it has power?

If wired up properly, Yes, it should have power all the time to provide constant protection (click here to see the different Mercathode systems and how they're wired).

You can test to see if it’s getting power but to determine if it is working properly requires proper testing (click here). Your Authorized Mercruiser Service Center can check your system for proper operation and since yours sits in brackish water a lot, I suggest a regular check of the system for peace of mind. I just had mine repaired, the controller went bad.


Do you have the anode above the cavitation plate in the front of the lower outdrive? If not, see about having it installed. I'm glad to hear you're using the magnesium anodes instead of the aluminum, it makes a big difference.



WetWilly

Thanks for the information. I've decided not to put on the SkegGuard. My primary fear is the mounting holes. It just seems to reason there is no way to protect the inside surface of the hole drilled in the Skeg. I really don't want to find out that the 1/4 holes become 1/2 down the road. The chip the Skeg only bothers me when it's on the trailer and I can't see it once I'm back in the slip.

I saw this the other day on Overtons web page. Its a skeg protector thats made of nylon comosite.

http://www.overtons.com/modperl/prod...ID=1008&r=view

I'm thinking of getting one for my boat.

Thanks jmills224,

Looks like you found a real viable alternative to the SS Skeg Guards!

Here's their site: Blackfin Skeg

Did a little Google and found some interesting reviews... Review #1 and Review #2

Now I'm contemplating going with the Blackfin and from what I'm reading, the real issue is getting it to stay on and I believe it's all in the prep and gluing that makes the difference.

Check out this clip where they beat up on the Blackfin and it seems to holds up great in the video.

Think I'll call Blackfin tomorrow for a little more info.

WetWilly

I don't know Willy... That video, while amusing, didn't impress me much. The guy didn't look like he was really swinging that hard, the lower unit wasn't even attached to anything allowing it to absorb some of the shock, and the truck running over it is like driving over a flat piece of plastic with soft tires - what could break???

And anyone that uses "dagum" in his advertisement makes me reconsider the validity of the message.

He sure makes an awful lot of promises too. Something that will get him in trouble.

I don't need the skeg guard yet, but I think I'm a fan of the stainless version.

I think that it looks like a bit of a 'cheap' solution. There weren't that many positive opinions in the "Review #1" that Willy noted and i have trouble believing some of the reviews in the ones at retailers websites. I could use to put a skeg-guard on mine as i have a smallish chunk missing out of the rear of the skeg. The composite one seems a little 'bulkish' & i suspect it might cause a little extra drag at higher speeds. The SS one seems to have a much cleaner look and likely fits better but it comes at an additional $30-40.

Interesting....I didn't know skeg breakage was that common. On our Volvo outdrive, the skeg is THICK cast iron as the rest of the drive assembly is. Seems like it would be hard to break that and not break the trim cylinders themselves.

From what i know, an impact like the ones showed in the video underwater underway would cause the trim cylinders to either break or release. I think some of them have a some sort of release that, upon sudden impact, allows the drive to kick up. It's far better to replace trim cylinders than repari the hull damage and replace the outdrive if it were to rip off the boat.

The Blackfin guys' argument that with this device, your outdrive and prop will be protected from damage is pretty rediculous. No skeg attachment will protect your prop from damage. It doesn't take much to bend a prop going down the lake if you clip a branch or other debris in the water. I know from experience.

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 

I beg to differ Mariah Man. My Z222 hit some of the old bridge structure at Jone's pass and destroyed the bottom piece of the Blackfin but saved my props. Plus with the added surface area of the Blackfin my boat handles like a sports car. When i dock and trailer the boat responds much better with the "bigger rudder" without having to throttle up. If you see a skeg with all the paint then it hasn't been in the water yet.:wink_thumbup: