prop antifouling paint

Michael T

Nice job taping-off the SS parts and I'm sure the Mercathode system!

06Rinker270

Idiot who painted to drive before painted he mercathode.  It's being replaced this week before I splash.

do you guys recommend 1 coat or 2 coats of the black finishing spray?

Cableguy Greg

How hard is it to replace the mercathode?

LaRea

A second coat would be a good idea since this is the first time you're applying it.  But, whether you do the second coat or not, you'll be doing touch-up next spring on any corrosion blisters that pop up.  So if you don't get the second coat done now, I wouldn't lose too much sleep over it.

06Rinker270

I intended on putting one on today but it says at this temperature it needs like 12 hours before a second coat.  Ill try and put one on before I splash if I can. Thanks LaRea.

Cableguy I will let you know how it goes this week when its replaced.  

aero3113

Looks great, and should prevent this from happening! LoL!!!!

06Rinker270

haha holy $@&!.  There are boats in my marina who have been sitting in the water that long.  That is insane.

randy56

thats not funny! salt water I guess.

Michael T

.....and some real bad shore power leakage in the vicinity.

Cableguy Greg

That boat must have never moved. How would you not notice your drives rotting away?

06Rinker270

None of you have boats like this in your marina? There is a nice, 2006 chapparel sitting in slip, canvas all the way around except for the back and it's just getting destroyed.  I can imagine what to drives are like. 

Here are the props all cleaned up.  Going to put Pettit prop paint on them and see how that holds up.  Look back to page one and see how bad they were.  Used the works toilet bowl cleaner to get fouling off and then sand paper to get off paint which was a PITA.

JBam67

Did mine this offseason- Sanded, 2 coats of primer, 2 coats of paint, 2 coats of clear coat,  2 coats of wax and hand cleaned and polished the props. and some new decals. I got a little bored this winter. lol Wish I took a before pic.

bella-vita

Looks awesome still waiting for marina to pull boat out so I can start on mine 

06Rinker270

Jbam, looks great.  Do you keep boat on a lift?

JBam67

06Rinker270 Thanks! No we do not have a lift, in the water all season.

Michael T

Beautiful work that will save you $$$$$$$

Handymans342

Finally finished mine.

bella-vita

Looking good

raybo3

Handy looks like your missing a couple of props.........lol

Handymans342

Mine are bigger LOL

06Rinker270

Dang those things look spanking new

Handymans342

Yeah but I'm **** at the marina because they had both drives off and could have easily blasted and painted them. 

Handymans342

Ray. Those are Diesel B2s. They do it slower and way more powerful with lots of motion. 

06Rinker270

Trying the Pettit prop paint to see how it holds up.

Handymans342

Did you use a primer first? Did you rough up the metal any?

06Rinker270

Can says only use primer if you want multi year otherwise says not necessary.  Just a test run for this stuff.  Put on 3 thin coats per instructions.

Yea I roughed it up with sandpaper.  Took a heII of a scrubbing to get the scaling and old paint off.

craigswardmtb

I just read this whole thread, that was a long one with lots of good feedback.  A couple comments from a guy that keeps his boat in saltwater for 7 months. 

1.  I have not had good luck with Trilux and particularly the spray on kind.  Looking at your fouling, 270, I would try something different.  Sounds like its too late.  Sorry i didn't post earlier.  I always use Pacifica Plus and literally have no fouling at the end of the season.  It is so much better in my mind for my area.  For the hard to reach areas with a brush I use rattle can Trilux.

2.  I always do at least two coats of antifouling.  If using spray on, I would do at least three.  One just does not hold up for me.  I suppose it is relative to the amount you use the boat.  I typically do 70 hours a season and two coats works for me.

3.  Spray on antifoulant looks great but in my experience it does not hold up nearly as well as brush on.

4.  My typical prep for the season, if in otherwise decent condition, is sand down with 120 grit, wipe down with 216 thinner, touch up any bare areas with a couple coats of Primocon (I usually do the whole lower unit), wipe down again, then brush apply two coats of Pacifica.  I leave all stainless and anodes clear of paint, and obviously the mercathode.  I painted my stainless trim tabs this year to try and combat the fouling.  I scuff sanded to make them rough, then did 3 coats of Primocon, and two of antifoulant.  We'll see how they hold up.

5.  The props I just use Works toilet bowl cleaner and a bit of polish.  I thought about using prop speed paint, but the fouling isn't too bad, so long as I use the boat.

craigswardmtb

Also I started using primocon on my bearing carrier, as it had some corrosion.  After one season it held up perfectly with no additional pitting, and the paint was in good shape.  It was somewhat of an experiment and I was pleasantly surprised.

06Rinker270

Thanks for the good info @craigswardmtb.  We will see how this years spray on works.  I am in brackish water but it's on the fresher side I believe around 2.6-5.0.  If it fails I'll go your method next season.

frenchship

Here is another proper way to paint the outdrives,maybe a long process and a bit expensive,
but will last a long time.


Painting Aluminum. It should be an oxymoron. But it happens. Especially aluminum out drives. I recently pulled my Mercruiser Bravo III. After 4 years of my paint job on it, not a single square inch of paint had eroded or peeled from the unit. Here is how I did it and some rules to remember when painting aluminum.

Number one. Aluminum will not take paint. Not bare aluminum, not etched aluminum? Surprised at “etched aluminum”? You see a lot of primers that say, “self etching”. Well etching is the process of using acids or bases to remove aluminum oxide and other contaminants. Where do the contaminants and oxides go in a “self etching” paint? That is correct, they are contained in the paint job. How long and how durable is a paint job with “self etching” paint after all those contaminants are contained therein?

Number two. Alodine will adhere tenaciously to aluminum and paint tenaciously to alodine. So alodine is our “negotiator” to paint aluminum. It provides the intermediary between paint and aluminum.

Surface prep. A lot of options here. If the paint job is original Mercruiser it comes off very easy because Mercruiser has a poor process. You can sand it off for the most part. If you want, you can get some “aircraft stripper” available at most automotive paint stores or Aircraft Spruce. The main difference here is the amount of ammonia in the stripper. What is critical in this process is to place several plastic bags over the input shaft and bearings and the prop shaft and carrier bearings and hold them in place with tape. If you have a nearby facility that does plastic bead blast paint removal, like an aircraft paint shop, they can clean off your drive as well. Just make sure to cover the pitot tube entrance on your drive. DO NOT SODA BLAST. You will make the etching process a very difficult one. Get the drive as best you can down to bare metal. DO NOT USE STEEL BRUSHES, STEEL WOOL, STAINLESS STELL BRUSHES, etc anywhere, any time. Always use aluminum oxide sandpaper and if you want a “brush” use Scotchbrite pad.

Etching. I use AlumnaPrep 33 available at Aircraft Spruce. You dilute it 1 part to 3 parts water. A quart bottle is more than enough for one drive. Follow the instructions on the bottle. USE RUBBER GLOVES. Brush the solution on generously. If you see a spot repel the solution it may have grease on it. Degrease it with acetone or MEK and put on more Alumnaprep. Leave the Alumanprep on at least 3 minutes then flush with fresh water. Use a hose. Flush like crazy. Your drive should have a dull but bright look to it after etching. Allow drive to air dry.

Alodine. Again available at Aircraft Spruce. Do not dilute. A quart will do a drive. Brush it on your dried, etched drive. Again, if you areas that are aluminum that repels the alodine, you go to de-grease. Clean and re-etch. Then alodine. Do not flush the alodine, allow it to air dry on. Your drive should have a nice “golden” tint to the bare metal.

Paint. Here is where you have some choices. I personally prefer two part epoxy polyurethanes. They are extremely durable, flexible (hard paints crack), and give an easy and very shiny finish that remains that way. The only negative is, any corrosion occurring beneath the paint surface will not be visible. The paint may bubble, but the coating will remain intact. Make sure you have sanded and etched away all previous corrosion before painting. I use Southern Polyurethanes. The other negative to polyurethane is you want a very good respirator and face shield when you paint. You can get one a Home Depot. Do not get the disposable kind. Get a 3M 4000 or 5000. Do not allow this stuff to get in your lungs. It does not come out, ever. Make sure your mask seals tightly around your face. If you have a beard, shave it.

Priming. I use Southern Polyurethanes Epoxy Primer. For a Mercruiser use black. Follow the instructions for mixing the hardener with the paint, (It is one to one). I use a small eight-ounce touch up gun. It just about covers a drive. First spray a flash coat, and then come back with a wet coat. After this when the wet coat is highly tacky and not subject to running, come back again with a full second coat. If you feel rich and want to burn some paint put on a third.

Zinc-Chromate Primer. A lot of people swear by this stuff. It is very good coating on etched aluminum, but not under water! It contains zinc! Think about that for a moment? There is one place to use zinc-chromate. On your bearing carrier after repainting the drive.

Color Coat. I use Southern Polyurethanes Universal Black, 4000 series. Again just like the primer, activate it one to one. Spray a flash coat then a wet coat. I do two applications. You’ll like this step because you’ll be amazed at how bright and shiny your drive is.

Clear Coat. You can (optional) clear coat your drive with Southern Polyurethanes Clear 4000 series. Do it just like the color coat. You can buff it if you want. Alternatively you can put on clear anti-fouling. You have to be prepared that clear anti fouling will “degloss” your finish and after a few weeks in the water, it looks like your drive is “cloudy”. Your underlying polyurethane finish is intact and is fine.


Refinishing. As I said, I recently removed my drive and the paint was intact, but I wanted to “clean her up”. I removed the clear anti fouling with #60 sandpaper. I roughed up the polyurethane finish coat with #60. In the process, I broke through to bare metal in a couple of spots. No problem. Etch those spots with AlumnaPrep, then alodine them. I sprayed two coats of Epoxy Primer, two Coats of 4000 black, then two Coats of Clear. Here are the results. Note the sheen near the bottom of the drive.




Sources of materials

http://www.southernpolyurethanes.com/Product%20lines.htm

http://www.aircraftspruce.com/index.html