Painting bare outdrive

[Stray Current]

If any of you have been following my 260 thread, you’ve seen that I’ve been chasing galvanic issues with my outdrive paint. I suspect I had the wrong paint applied at some point before my ownership. Everything else in the bonding/anode system checks out

She’s been blasted bare. I should have had him go more aggressively on the pitting but I wasn’t sure of the casting thickness. I may have it re blasted as this got back-burnered after hurricane Ian. Newer transom assembly isn’t experiencing the same issues so that will simply be top coated at final assembly.

So now I’m trying to settle on a final paint process, and I would like some input.

at this point I’m thinking:

alumiprep33, aggressively mixed
Alodine
Interprotect 2000E thinned, sprayed 3-4 coats
Trilux 33 2-3 coats

what are your thoughts? I’d like to avoid having to hire a professional painter to lay a urethane coat. They’re all backed up at least 6 months with all the hurricane damage on boats and vehicles. I’m trying to be back in the water by March at the latest to start demoing for sale.

 

[Nater Potater]

Those pits do look a bit scary. You might consider going the Marine JB Weld approach. If nothing else, it'll give you a smoother base to paint. I went through something similar with my Alphas. You can see how we started on ours at http://www.clubsearay.com/index.php?threads/nater-potaters-build-thread.109864/page-3#post-1342014 As the paint instructions make mention of, you only have so long between surface prep and the first coat, as aluminum will grow a native oxide layer within a couple of hours, rendering future paint adhesion almost nill. Use rubber gloves to keep your greasy fingerprints off of the bare metal. This is definitely a case of "Cleanliness is next to Godliness".

 

[Stray Current]

Those pits do look a bit scary. You might consider going the Marine JB Weld approach. If nothing else, it'll give you a smoother base to paint. I went through something similar with my Alphas. You can see how we started on ours at http://www.clubsearay.com/index.php?threads/nater-potaters-build-thread.109864/page-3#post-1342014 As the paint instructions make mention of, you only have so long between surface prep and the first coat, as aluminum will grow a native oxide layer within a couple of hours, rendering future paint adhesion almost nill. Use rubber gloves to keep your greasy fingerprints off of the bare metal. This is definitely a case of "Cleanliness is next to Godliness".

i honestly don’t care too much about the pits, as long as the glass bead doesn’t penetrate the case. They’re not as bad as they look but I’m still not sure about the thickness. I’m not going to bother filling and fairing but if I can get the corrosion stopped I’ll be happy.

I’m figuring the alumiprep should kill the oxide layer and maybe finalize cleaning those pits after a second blast. I may just hit with my dry bead blaster instead of the wet blast I had done. Everything I’m reading says the acid will remove the oxide layer and if I get solvent washed quickly after a rinse and get the alodine on I’ll be good.

I’ll check out your thread, but does that sound like the right track?

 

[Nater Potater]

Everything I’m reading says the acid will remove the oxide layer and if I get solvent washed quickly after a rinse and get the alodine on I’ll be good.

I’ll check out your thread, but does that sound like the right track?

That ought to do it. I wish I'd invested in a sand-blast gun and filled it with glass beads. It'd have made things a bunch easier/quicker.

 

[techmitch]

Your best bet IMHO is https://www.amazon.com/Moeller-0254...ds=zinc+chromate+primer&qid=1670722673&sr=8-3
or the like and as @Nater Potater said, time management between surface prep and the first coat is imperative.

 

[Scott06]

Corrosion you see is typical of bravo 3 drives. I would make sure you have a mercathode, maybe two. My buddy who experienced similar corrosion added a second mercathode system with pucks on the transom.
For paint i would look at something like PPG DP90 epoxy primer. Great corrosion resistance. If you have a PPG auto body supply house they can set you up

 

[ttmott]

One thing though whatever you end up doing is the pitting needs to be cleaned out. The paint system will fail over the pitting if not taken down to the base aluminum.

 

[Brite Idea]

I remember someone posted that he used an etch before priming and then a rinse then the Alodine before using Primecon then Trilux. Interprotect 2000E is a barrier coat for boat bottoms and in my opinion over kill for an outdrive. You are in Florida so I get it you are fighting a tough battle against growth & corrosion. I have my boat in the water seven months a year up here in NY but you're probably in the water for most of the year? If I wet slipped in Florida with an outdrive I'd haul the boat quarterly for drive maintenance. I've enjoyed your posts and give you credit because people call me a maintenance nut but I don't come close to you! Let us see the finished paint job when you're done.

 

[Little Ducky]

Your outdrives look brand new compared to mine. But they are still running great albeit on borrowed time. I just got an estimate to do new lowers on both OR to replace the entire drive itself. Time to start saving my pennies.

 

[Stray Current]

Its looking like I’m going to go with the Pettit system. I did take some time last week with my glass bead blaster and dug out some more oxide from the pits. Once I get some more blast media I should be able to get it to the point where the alumiprep get all of the remainder.

I need to call Pettit and see what they say about the additional step of using alodine. I also want to speak to them about filling in the pits to see if they should be filled before or after the base primer.

Once I’m all primed I’m going to paint the drive in Pettit Vivid yellow as the base paint. I’ll be using either trilux or ultima eco in black as the final coat. The idea behind this that as the ablative wears away or begins to bubble it will be easier to see during the regular sandbar trips where I scrub the anodes and waterlines while swimming.

While I’m out of the water I’m going to replace the trim sender and look into the additional transom pucks for the mercathode and red controller. Unfortunately the one I purchased from partsvu was defective and they told me go scratch, so I’ll be shopping for that elsewhere.

 

[Brite Idea]

I also have the usual pitting on a twelve year old pair of Bravo III's. As per my mechanic who HATES Bravo III's because of the corrosion issues, he has told me more than once to change my lower units to Bravo II's and he says that's it problem solved you'll never have corrosion or mechanical issues again. He says the Bravo II's are truly Bullitt proof!!

 

[scoflaw]

I also have the usual pitting on a twelve year old pair of Bravo III's. As per my mechanic who HATES Bravo III's because of the corrosion issues, he has told me more than once to change my lower units to Bravo II's and he says that's it problem solved you'll never have corrosion or mechanical issues again. He says the Bravo II's are truly Bullitt proof!!

I'd say your guy doesn't know much. That B2 has a very large diameter prop and is made to push a very heavy boat slowly. Horsepower sponge so to speak, also the weak link to all Bravo drives is the upper gear set which is identical to all 3 Bravo's. Some people think the B2 is bulletproof because there're paired with a low power engine that is incapable of producing enough power to destroy it.

 

[Brite Idea]

Scoflaw I really have to agree with you on what you say but to clarify my mechanic has said this mostly regarding boats like mine 14000 lbs and under powered. He says that the heavy cruisers with Bravo II's have no corrosion issues and really aren't fast boats so the Bravo III issues just aren't worth the trouble.

 

[scoflaw]

Agree with that, I've owned boats with all 3 drives. The B2 was on a 2000 245 Weekender with a 5.0 Top speed 34mph, but 0 corrosion. That was 1 boat that could have used a B3