Outdrive Paint Recommendations?

YYZRC

I painted my Bravo III drives last winter with the Merc primer, Merc phantom black paint and Merc clear coat. They looked brand new. 

Now, they look like they are 20 years old after 5 months in fresh water. Can anyone recommend a quality paint?

PickleRick

What prep process did you take to clean, scuff and then reclean the surface before paint application?  

I'm assuming the merc prime is intended specifically for the aluminum drive but on anything aluminum, stainless or plastic I like to add adhesive promoter to the surface before I prime. Seems to leave a better lasting finish. 

Also avoid steel wire when prepping aluminum or stainless. 

LaRea

What he said ... but I'd suspect stray current from neighboring boats.  Even if your paint job was less than perfect, five months in fresh water shouldn't do that.  And if it's stray current, any paint is going to fail.  

YYZRC

Some of the drive was down to bare aluminum. Most was lightly sanded. 

PickleRick

How did you clean it?  If you don't clean and degrease the drive before sanding you are working grease, waxes and oils into your drive.   

A good wash with purple power or even dawn dish soap, warm water and good scrub brush should be sufficient. 

Then after sanding the engine drive well with im assuming 220 is recommend for that you need to clean as second time.  Repeat the good warm water wash and then go back and clean with a mix of 50/50 water and isopropyl alcohol. Walmart is the cheapest, from the pharmacy section.   Clean and wipe off with white lint free towels until you no longer see any dirt coming up.  

Now you're ready to start applying. 

There is a flash time likely between the prime and paint.  If you'd wait too long and it dries you'll need to sand, clean and then paint.  



Sadly, if the surface isnt prepped well just the force of the water under operation will peel the paint off quickly leaving the exposed non painted surface to quick corrosion.  The coatings that hold the best do so with both a chemical and mechanical bond.  Make sure whatever paint/primer you go with is compatible and follow instructions as closely as possible.  Simple thing things like air temp and humidity can have a large effect on the durability of the finish.  


You'll see cars with paint peeling off the front bumpers all the time where a cheap body shop or used car lot just sprayed a cheap Chinese replacement bumper with zero preparation or lack of proper prep put into the paint job. 

PickleRick

Sorry for the typos. This new phone hates me. 

laureniac1

Check out some of my past posts- truilux 33- while it is not shiny and pretty it stops the corrosion. I did the same thing paint them pretty and than be disappointed 5 months later . 

LaRea

I did touchup with Primocon and Trilux every season for years.  Springtime ritual.  But when my neighbor with a derelict sailboat moved farther down the dock, the corrosion went down by about 75%.  

YYZRC

@PickleRick the paint didn't peel. It went almost milky looking in many spots. Very strange for sure.

After a bunch of research, I'm going to try this epoxy based paint: https://www.protekpaint.com/product/2k-epoxy-reusable-spray-paint/



If it fails to impress, I'll switch to Trilux 33 antifouling paint and move on.

PickleRick

I'm no paint expert but I believe what you're describing is called blushing.  Usually happens when it's too humid when you're spraying.  

I fight the shop owner with this as he thinks rainy days when the shop is slow would be the best time to paint his projects.  Which it would be if we had a temp and humidity controlled paint booth instead of a 1930s gas station cinder block building.  

I guess it could also be fish eye which is caused by some sort of grease, oil, wax or other contamination being on the painted surface.   

Liberty44140

X2 on trilux 

YYZRC

I sprayed them in my garage in winter. Couldn’t have been over 20% humidity at the time. Oh well!

Ian

I used to be picky about painting them and used the Merc black. Was told by a professional paint person rust oleum is the same formula. Each year clean off and dry and blast with the black rust oleum. Comes out looking the same each year as it did with the Merc black and being fussy.

Liberty44140

With my first Rinker the glossy black was just never worth it. I’d do all this work in the spring and they looked great for a few weeks, then come out in the fall looking like I’d done nothing. No reason to make them nice and glossy unless you are trailer or lift. The trilux on my 342 was MUCH better. Every spring I’d buy one can, do some light touch up, and off we’d go. Came out in the fall looking 90% as they did at launch. Yes it’s a matte black like bottom paint but again no need for showroom gloss on an in water slip boat. 

YYZRC

@Liberty44140 while I agree that the drives don't need to look pretty, the antifouling builds up around the inlet holes which is concerning as I don't have the thru-hull pickups on this boat. Also, brush application sucks.

Liberty44140

Agree, so the trilux spray cans are the better way to go. Very thin so no buildup and easy application.