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bblauvelt 03-15-2008 01:37 AM

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.

WetWilly 03-15-2008 08:19 AM

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

bblauvelt 03-18-2008 01:27 AM

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.

jmills224 03-19-2008 01:37 AM

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.

WetWilly 03-19-2008 03:50 AM

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

indykoch 03-19-2008 02:25 PM

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.

mikeyt 03-19-2008 03:11 PM

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.

WetWilly 03-19-2008 08:29 PM

Hi indykoch and mikeyt,

I agree with the both of you, as for the video, yea, it looks pretty hokey...and doesn't really prove anything as well. Now if they bolted it down, took a an oak 4x4 and gave it a Barry Bonds swing.... :yes_grin:

From what I'm sensing, this works best on outboards, by design, they pop up much easier and faster after an underwater strike than an IO does so a good part of the the impact energy would be transfered into motion.

I'm still willing to give it a go, you never know, it might just be as good as they say, than again.....

I'll let you know when I have more info on it!

WetWilly

MariahMan 03-20-2008 06:14 PM

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.

backwater bill 11-28-2009 02:29 AM

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:

backwater bill 11-28-2009 02:33 AM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
Brother when you drill holes in your lower unit not only void the warranty but weaken the skeg.

MariahMan 11-28-2009 05:34 AM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
Backwater Bill, thanks for posting your experience with this product. That's interesting to hear. It does sound like the product has made a difference for you and improved the handling of your boat. WetWilly, did you ever get some more info on the product?

WetWilly 11-29-2009 08:15 AM

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

OK, so far, this is what I've come up with about the BlackFin skeg:

The Good:

1) The BlackFin appears to be pretty darn strong, as the original video and the creators claimed. With the exception of member backwater bill, I haven't really found anyone else saying that they broke one although the bottom of the BlackFin is designed as a sacrificial node.

2) Several other Alpha I/O owners have indicated that they experience better control especially at low speeds like member backwater bill stated, but I have also read reviews about a couple of boats now getting a bit squrrely near WOT with the BlackFin as well.

3) Babe Winkelman — An icon in the fishing and hunting industry and host of "Good Fishing" and "Outdoor Secrets," now endorses The Blackfin skeg.

4) Zero galvanic corrosion caused with this product unlike SS Skeg guards.

5) Cheaper than SS Skeg guards or a new skeg.

The Bad:

1) It appears that some BlackFins are still falling off. Some owners notice either after a strike or when they pull their boat from the water, the BlackFin is gone. It's interesting to note that most of these same people claim to have followed the installation instruction to the letter.

2) I found a couple of owners stating that they're experiencing handling issues near WOT with the BlackFin, either the boat now gets squirrelly or "chine walking gets very wicked".

3) If it should come off, you may be stuck with an adhesive mess that may be difficult to remove. (It would have been interesting to know if the adhesive stayed on the skeg or the BlackFin when it fell off)

Conclusion:

The BlaskFin appears to be a strong product and most of the reviews for the Blackfin seem very positive. Several reviews have indicated that the Blackfin seems to favor Alpha IO's with better handelling at lower speeds. There is still the issue of the Fins falling off but BlackFin's warranty seems to indicate that they will replace it within the first two years if that happens (click here).

In the event I should damage my skeg and require another fix, I will try the BlackFin myself to see how well it works on a Bravo outdrive.

WetWilly

P.S. backwater bill, I assume that you have or will be replacing your BlackFin, if you don't mind, I would like to know how difficult or messy it gets in removing the old BlackFin and adhesive in preparation for the new one.

backwater bill 08-18-2010 07:42 PM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
Hokey is probably so the average Joe can understand. As for prop protection, the Blackfin it slightly taller than the original skeg by about 1' inch. That is 1 very crucial inch when it come to running over obstruction. Why else would so many rental boat companies use them. Because they save them money.

backwater bill 08-18-2010 07:48 PM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
Stainless steel vs cast aluminum. Who is going to survive that battle when you hit something???? Stainless absorbs NOTHING it just transfers the shock to the aluminum and breaks it off clean with the 2 holes you drilled in the skeg you are trying to protect. FYI drilling holes in your skeg voids any warranty you have.

backwater bill 08-18-2010 07:56 PM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
Follow instructions and there will be no problems.

garyg 08-18-2010 10:53 PM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
1 Attachment(s)
Hi here's my 2 cents worth I have a 2000 Z Shaba open bow 7.4 MPI BRAVO 111. I just put a new Skeggard on my Z 272 and has already saved my props. I would check with Skeggard about there thoughts on the galvanic corrosion. They have always been very helpful to me. I have enclosed a picture of my skeggard Gary G:wink_thumbup:

backwater bill 08-19-2010 12:16 AM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
Sweet boat but realize that the toughest metal on the unit is the prop and gard. If you hit hard the gard will not budge and the aluminum lower unit will have to. The Blachfin is designed to absorb the impact before it reaches the unit and/or be sacrificed to minimize damage.

indykoch 08-24-2010 03:31 PM

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

Originally Posted by backwater bill (Post 25108)
Sweet boat but realize that the toughest metal on the unit is the prop and gard. If you hit hard the gard will not budge and the aluminum lower unit will have to. The Blachfin is designed to absorb the impact before it reaches the unit and/or be sacrificed to minimize damage.

Actually, I've always heard MerCruiser (and I assume Volvo for that matter) have a "built in" insurance for this - the hydraulic trim cylinders are supposed to give way for submerged objects to save the outdrive (allows it to flip up). If this is true, I think the release of the lower unit would happen before actually breaking the metal. Devil's advocate - I've also seen a LOT of damaged lower units, so who knows if this system actually works or not. :shakehead:

baker721 06-16-2011 08:38 PM

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

Originally Posted by WetWilly (Post 4718)
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.

WetWilly

:rolling_laugh: I did that the other day

darkcalling 06-17-2011 11:16 PM

Re: Bravo III + Stainless Skeg Guard = Galvanic corrosion (Yes/No?)
 
Well I can tell the two times:o I hit something with my Alpha 1 the lower unit got trashed one the skeg hit no prop damage the other my mirage prop hit something again prop lived being ss the leg twisted so I would say the ss gard would only increase your odds of leg dmg who knows with the fin if it would absorb enough. Just my two cents


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