Refinishing bravo 3 HELP!!

Trashman

 The po of my 270 kept it in fresh/brackish water for the last 2 yrs. before that in stone harbor nj( salt), he kept the salt water zinks on. Told me corrosion had been at its worst the last 2 yrs.  I still haven't checked the Mercathode below the trim manifold but plan to just replace. There were a few if the little ground cables busted. 
I'm keeping it in the Delaware river , brackish/ fresh, I guess. 
• I went with new magnesium anodes, good???
• wire wheeled the bad corrosion  and will finish off with some sandpaper to smooth things out there will be quite a bit of spots with bare aluminum,I'm trying to keep as much factory paint on as possible.  What do I use to prep the drive for paint?
•What do I use to primer the bare aluminum ?
•There are a few heavy dimples, can I fill these with something before priming or it's no real concern?
•I saw a video where a fella used JB Weld to fill and smooth out his skeg, has anyone done this ?
So many videos, can't decide just what is PROVEN to be the best way to refinish my b3. 
Heres a pic of what I've started with and what I've done so far. 

rasbury

wow! You really went after it! If you do a search, I recently touched mine up. The marina had the merc paint but another band prep, check the post. You have to put down a prep of a zinc based product for the black to stick. You have a lot to paint- just realize your probably not going to get a "factory" paint job unless you take things apart.
good luck!

Gregg

First thing you should tape and paper off all areas,to the drive and lower shaft area.feather out your grinder marks with 120 and go up 400 grit paper.As to your pitted areas in less your going to pull it apart your making a lot of work for your self,it will get it to the cracks of the case. make sure it is really clean prior to priming with zinc chromate and just take your time.

Trashman

 Pardon my ignorance but is zinc chromate a merc product? As far as how much I've removed, the corrosion was pretty bad.  Looks like po just slathered bottom paint over it. Really don't have much choice if I'm going to make it better.... I think. I used a wire wheel so far and do plan to smooth things out.  As for cleaning , acid? Acetone? What should I use to prep for primer.  And as far as the pitting, do I just sand as smooth as possible?  Sorry for all the questions, just wanna get it right 

Gregg

Merc does sell a zinc primer,but if you have a  automotive paint supplier jobber near by you might try them. As to cleaning there are precleans for aluminum which are a lite acid wash. The wire wheel works well,just try and make sure you remove as much.of  the corrosion out of the pitted area. If you have a dermal tool with a wire wheel it gets Into small areas quit well with out removing a lot of material.

Gregg

Prior to zinc primer only blow off with,air or vacuum. 

Trashman

Ok great. I have several acids at my disposal. Some for brightening aluminum. Pits are "ok" I guess as long as there are cleaned out. As far as final coat, I'm assuming use merc black paint. Thanks for all the info. Any other dos n don'ts are welcome , of course. 

Gregg

Just make sure it is clean and dry,prep is every thing. Do not wash with acid prior to priming only as a pre clean. 

planesailing

I'm currently in the process of prepping my drive for paint also. Any areas to avoid painting?

Trashman

@rasbury, read your thread on painting your drive.  Some good info.  Just wondering how the paint job is holding up. I did purchase a new set of grounding cables and I'm hoping all my screws come out without snapping!!!!  Lol

Pam

I repainted mine last spring, Stripe of all of the original paint. Filed pittings with Epoxy. I basically followed the knowledge presented in the link below but since some of the chemicals mentioned is not available in Sweden I substituted those to the closes match available. It´'s only been one season since so I have no long term experience of its durability. 

http://www.boatered.com/forum/topic.asp?TOPIC_ID=97217

jhofmann

I used JB weld to fill in pitted areas om my outdrive 3 years ago and its still holding strong. Just make sure not to fill in any seams where the case goes together in case you need to take it apart. Sand smooth, clean with laquer thinner, spray with a good zinc chromate primer, then Merc Phantom black. Top with a clear coat if desired for a deep shine.

Trashman

@jhoffman do you trailer or leave your boat in a slip? Im glad you chimed in with the jb weld filling the pits. I really wanted to do this.  

jhofmann

I trailer most of the time, except when I'm on vacation, then it stays in the water.

rasbury

@Trashman so far, so good....watch how much paint you put on however. My first coat came out real nice and shinny. I should have stopped there. I put a second coat on and now it's kind of dull/overspray looking. I might try to rub it out a bit but otherwise very good. I did get a little overspray on the props- came right off when I ran the boat. Looks like the paint so far is holding up but have only run for one trip but I think it will be fine. Good luck!

06Rinker270

If you want to read what not to do, learn from a bunch of wise gents on this site how to correct it, then see me correct it.  Click below:  https://rinkerboats.vanillaforums.com/discussion/4399/prop-antifouling-paint

Basically sand down corrosion to bare metal like you have done , I used 80 grit wet dry from 3m.  Rough up existing paint(various grits depending upon if its drive paint or the Merc factory paint).  Clean drive with tack rag or some sort of cleaner, others have used vinegar, paint thinner,etc.  I took off props to clean them and grease the shaft, also makes it easier to paint.  Tape off the electrode underneath the gimbal housing, hull, wire mesh trim hoses, prop shaft, trim cylinder shafts.  I did 2 coats of  Trilux Primocon primer.  Some say do white coat then grey coat so you can see where you painted.  Some use zinc chromate, I didnt, not sure if its necessary or not.  Most didnt say to use it.  Then two coats of finish paint.  I am going to use Pettit prop paint, see how it holds.  WAY cheaper than prop speed.  

If I missed any steps anyone please fill in, I am not an expert by any means.    

Trashman

@Pam, that info was very informative. I am looking into prepping the bare aluminum with alodine.  I bought the phantom black and zink chromate already. Just doing a little more research on paints. 
@Alswagg, I actually have a good connection for getting powdercoating done but my feelings are that I already have significant corrosion and feel PC may not be in my best interest. Also, id have to take it all apart. That would require more special tools and way more knowledge than I possess.  
In no rush, the drive is on the stand and I am chipping away at it a little each day.  Let the advise keep rolling in.  Lol. 

Trashman

Just a quick update.  I sandblasted the bell housing with glass bead.  Did a nice job.  I acid washed the housing a few times until I got all the surface to react to the acid.  Takes a few applications with a spray bottle to get it to remove all surface contamination.   Don't leave acid on too long it will burn the alum a dark color. Next I sprayed with alodine let it stay wet for 15 mins or so then washed then repeated until I got the desired "golden tint" on the aluminum.   Washed with water and let dry overnight.  
Next wa a few coats of zinc chromate, green .  Then several Coates 15 mins apart, of mercruiser phantom black. 2 light Coates on the mating surface where outdrive bolts together.  Still contemplating another coat after it's been sitting a day or two.  
 ...Currently working on the drive.  

randy56

wow, and when you started this thread, you said help. You can teach. Did your outdrive have a shower on it?

Michael T

Best drive prep and paint job I have seen in 50 years of this type of effort! IMO.....TEXTBOOK!

MarkB

Very good quality work!

bella-vita

Looks as good as  new again 

Trashman

Wow thanks.  Let me explain the dark spots.   The po used a sacrificial bottom paint on the drives.  I used a gel paint remover and pressure washed.... No good.  All I did was liquify the paint and drive it into the porous aluminum.
These had to be media blasted.  
FAIRLY EASY!!!
I used a small blaster I borrowed.  Looks like it would hold 10 gallon.  
Started out using the black 70grit media that was in the blaster.   Was ok but left a finish similar to 900 grit sandpaper.   
I bought 80 grit glass beads better finish for sure, like 1500 grit sand paper. $44 at harbor freight for 50lb.  Reused about half I recovered off the tarp after sifting. 
Had to do at a friends house because the blaster needs a good sized compressor.   Makes a mess! 
I put the drive on a wheel barrow on top of a tarp. Not ideal but was limited to what was available.
wore a tyvek with hood, goggles, good leather gloves.   The media gets everywhere!!!!  In hindsight I would suggest buying the cheap little hood for your head and ear muffs.  
I worked on the drive last nite, here's a few pics...

Trashman

Handymans342

It seems to me that Mercury is behind the times when it comes to corrosion protection and materials used to construct the drives compared to others 

jme097

Agreed handy

Liberty44140

Coming along nicely. I am following this close as I plan to either have this done to my B3's or so myself next winter. Do you plan to remove and replace the bearing carrier? 

Trashman

@ liberty, I'm undecided.   I have to look at the breakdown and see what's what. My decision right now is to carefully remove all the loose corrosion and paint it's kind of one of those things where I feel leave well enough alone I don't know how  much thread or where the seals are for that thing.   It was my main concern with the entire job,that's where most of the corrosion occurred    I currently have the lower casing in my eBay search just to get an idea of what they go for pricewise    The logical thing to do would be to replace that lower casing I'm sure I'll have to cross that bridge eventually.  

Liberty44140

Ok, thats is interesting. If you leave the carriers alone, will you seal them with a good primer or even a two part epoxy primer before painting so that they are protected?

Liberty44140

@trashman here is what I did just a few weeks ago. The plan is for this to be a one to two year band aid until I can grind them down, fill low spots and re paint the right way. I will replace the bearing carriers when I do that. Don't know why they are out of order:

2- Bearing carriers with a light coat of epoxy to seal. I cleaned out all of the corrosion first. Corrosion was mostly bearing carriers and a little on the drive near the prop. 

1- starting point. Someone painted them with Trilux years ago and neglected anodes.
4- final, new anodes 
3- done but props not on yet. Painted with fresh Trilux 33. This was before I sanded and repainted the transom too. 

Youllbefine

Liberty, ....I noticed that it looks like you have the bottom paint on the transom communicating with your outer gimbal.  I believe this is a no no from a corrosion standpoint.