Removing oxidation from Bravo III

[Speakrdude]

Am about to begin refinishing my Bravo III's and before I use STRAIGHT Muriatic acid (Lowes 14%) and take a chance on melting a $5000.00 drive, Thought I would check and see if anyone recommends diluting, not doing it at all, different method, etc.
I plan to only briefly, use muriatic acid to get the white rust rust out, (30-60 seconds) then flush with water or baking soda to neutralize, then sand, prep, paint.

 

[Speakrdude]

 

[DeepBlue2010]

I just did the same job few weeks ago. Did not use Muriatic acid, I went to Wesco auto-body supplies and got DX533 as a part of my entire restoration system.


I forgot almost all I learned in the industrial chemistry classes so I am not going to argue against your approach. But from what I read on the forums, I would not try it myself.

 

[Speakrdude]

How did yours turn out? I'm always a good listener!

 

[Speakrdude]

So it looks like the DX533 system is Diluted Phosphoric acid. I just so happen to have that too!
And then Alumi prep.

 

[littlerayray]

Let us know how it turns out with pics

 

[DeepBlue2010]

I am not sure if LittleRayRay was talking to me or to you about the pics but mine turned out great. I used a stainless steel brush on an angle grinder and removed all rust and oxidization. DX533, then 503 per instruction sheet then my paint system (POR15) the only thing that went wrong was to "follow" the instruction sheet for the top coat (hard nose) and apply the second coat in 20-30 minutes. it wrinkled. There is another paragraph in the sheet says "for best results, allow 2-3 hours between coats" how the heck it is 20-30 minutes in one section and 2-3 hours in another section of the same sheet, I will never know.

 

[littlerayray]

I was talking to both

 

[alldodge]

From my view point I thing the mercathode system needs to be checked and the carrier may need to be replaced

 

[DeepBlue2010]

Good call AllDodge, the electrical system needs to be checked also for faulty wiring otherwise the corrosion will show its ugly face again. Here is mine after the final coat of top coat. It is not perfect since I had to sand off the wrinkles and shoot again but it will protect my outdrive for a while. Bravo III are not cheap

I owe any success in this job to Zool, an experienced member of iBoats and active in the restoration forum. Very helpful
I owe all screwups to myself, should have tried the second coat on a scarp. Oh, well. Lesson learned. Don't trust datasheets. who knew?!

 

[Speakrdude]

I will "very meticulously" check the bonding system, Mercathode system, and replacing all the anodes with the proper ones.
I amazes me how many shop owners don't understand the difference between, zinc, aluminum, and magnesium.
As far as the carrier goes, just a simple pressure test?

 

[alldodge]

As far as the carrier goes, just a simple pressure test?

The carrier preloads the bearing race against the roller bearing. Pressure test determines if the seals are leaking, not the structural integrity of the metal. While the carrier does not handle the major torque load of the prop, it does maintain the radial load of the prop shafts. If you can clean it up and everything will be OK, don't know. If it were mine I would be doing a close inspection and determine how much metal has eroded.

 

[littlerayray]

Those look brand new deep blue I'm impressed especially since I like shiny

 

[Speakrdude]

Here are the Pics of my two Bravo's. OOne seems to be missing the nylon piece that cover the outer seal. Do these look ok? Can I replace the nylon seal only?

 

[alldodge]

No, the nylon piece is part of the seal and has to be replaced as one piece. There is a possibility that one drive had the seal replaced with the new style seal and the other didn't.

 

[Bt Doctur]

not corrosion or oxidation , its electrolysis. sometimes 2 mercathods are necessary and make sure all the bonding wires/connections are in good condition

 

[Speakrdude]

So, as long as it passes the pressure test, run it?