How do I paint outdrives?

walleye

On my spring to-do list before launching is to paint the outdrives.  I've never done, though my mechanic suggested it and said there was a product I could get that was essentially in spray can form.  Can you provide some guidance as to the best way to do this, including prep, application and product?  Thanks much.  Drives are twin Bravo 3s. 

LaRea

Where do you keep the boat?  Salt or fresh water?  Stored on a lift, or stored in the water?

What's the general condition of the drives?  New, old, any signs of corrosion?  If there's any corrosion at all, you'll need to sand down those areas to bright metal, and apply a primer and paint specifically made for aluminum outdrives.  Be absolutely certain the paint is for outdrives.  You can't use hull bottom paint.  

Don't use a steel wire brush.  Use either sandpaper or a stainless steel brush.

Make sure you mask off the Mercathode (under the drive at the transom) and the trim cylinder shafts.  

Your tech was probably talking about Interlux Trilux.  It's very popular - not cheap but it's an effective anti-fouling paint. If you store the boat in the water, that's probably the way to go.  

If you store on a lift, you'll probably want a glossy paint because fouling won't be an issue and you'll want the drives to look good.  

walleye

Thanks LaRea. Great feedback; very helpful. Boat is in freshwater. I'm in DC, so just up the river from you. 

LaRea

Cool, what marina?  

Trilux will work great for you.  It'll keep the moss growth way down.  If the drives still have the original paint, and you're planning to paint the entire drive, you'll need to lightly sand the original paint.  Then apply a coat of Primocon and two coats of Trilux.  Paint the first coat a different color from the final coat so you can see what you've painted.

walleye

Hey guys, hope you all had a nice holiday. Quick follow up on this. What grit sandpaper should I use for cleaning / prep of the outdrives to get off the gunk and get them ready for the primacon and trilux?

Handymans342

100 to 120.  Do. They look new now?

LaRea

Remove the props first.  I'd try some hull cleaner like On & Off or Starbrite to take off the moss and scum.  Rinse with water, then wipe down with paint thinner.  Use 220 grit to scuff up the factory paint.  For corrosion spots, start with 80, then 150 then 220.  Then wipe down with paint thinner a couple times.  Mask the hull, prop shaft, cylinder shafts, Mercathode and hoses.

I leave the anodes attached during painting, and then replace them with fresh ones.  If you're not replacing anodes, don't paint them.

To paint, start with the drive all the way up and turned to one side.  Paint everything you can easily reach.  Turn steering wheel all the way to other side and paint. Then lower the drive and paint, then turn to other side and paint.  It helps having an assistant to work the trim buttons and steering wheel.

For masking the cylinder shafts, you need the masking to flex as you move the drive up and down.  Here's what I do:  with the cylinder fully extended, I wrap the shaft with a piece of plastic cut from a trash bag.  Then I tape it at both ends like a sleeve.  

rasbury

I have a lite amount of corrosion in a couple of  spots on the lower foot that really bother me...please keep this going until the projects done and take some before and after...

Cableguy Greg

When I paint my drive, I use green zinc chromate primer for a few primer coats. It is a must for the corrosion spots that are bare aluminum.

walleye

Thanks guys. LaRea, very helpful info! Handy, last time I saw them (after getting hauled out) in early Nov they had lots of Potomac scum. (LaRea knows all about this!) I don't recall if they had any corrosion after they were sprayed down. I don't think they did (sure hope not...) but I will know for sure in March when I get back to the yard to start doing some spring prep, including this project. I will take some before and after pics and post them then. 

walleye

LaRea is this a one-day job or do I want to let the primer set for at least a day prior to applying the trilux?

LaRea

Since it's the first time painting them, you might want to consider two coats of primer.  You'll need one day for primer and a day for paint.  I think it's four hours between coats.

walleye

LaRea mentioned removing the props for this job.  That got me thinking:
1) do I need a special prop wrench for that?  Or will a 1.5inch socket and a pipe wrench work?  
2) should I be removing the props for shaft inspection/lube every season?  
Never done this job so any tips are appreciated!  Thanks guys.

Michael T

To sand I use professional type cloth backed paper and finish wet sand with 1000 grade.  After painting wait until you are sure the drive is dry then bathe it in cold water to set the paint,  then gently dry it with a soft towel 
,  wait a day then wax it and buff it with a soft towel.  Always touch up chips and scratches promptly. 

LaRea

Socket plus a really big pipe wrench or channel lock pliers will work.  Bring a piece of 2x4 and wedge it between the prop and cavitation plate to keep the prop from turning.

I do mine every season.  Clean and lube the props, refresh the paint, replace the anodes.  On the Bravo drives, you really need to stay one step ahead of corrosion -- even in fresh water.

Handymans342

What if your boat is kept on a lift? Half of my paint is worn off. But do I really need to paint them? 

jme097

Are you guys referring to Interlux Trilux 33? (Link below). Why not use the Merc Cruiser outdrive paint? Just curious as to the integrity of both products I guess. What primer would you guys use as well?

http://www.jmsonline.net/interlux-trilux-33-aerosol-black-yba063a16.htm?utm_source=google_shopping&gclid=CLiYp-Cqs8oCFZOBaQodyRQLxQ

LaRea

Lift-kept boats -- no.  Handy and the other fortunate owners with lifts get to debate which brand of wax will look best on their outdrives.  The rest of us don't have it so good! 

I'm using Trilux, with Primocon as the primer.  It prevents growth of moss, which is the main culprit in my area.  I'm guessing it's also good for salt-water evils such as barnacles.

In my experience, the durability of the paint isn't a big deal because I always end up repainting every spring.  After a season in the water, there are always at least a few new spots of corrosion to deal with.  Since I have to clean up the drives anyway to repaint the corrosion, why not go ahead and paint the entire drive.

Excessive?  Maybe.  I could just touch up the corrosion spots, but I like having fresh paint every spring.

Handymans342

Here is my drives, need paint hey?

walleye

LaRea, how do you clean the props -- do you sand and/or scrape any crud off of the inside prior to putting them back on?  Since this is the first time I'll have pulled them and I don't know when P.O. last did, I'm not sure what to expect when I pull them in terms of growth or calcium type crud caked up in there.  Sorry for all the questions!

Michael T

Geez,  Steve you should show those drives some TLC. 

Michael T

Once the props are off and the drive shafts cleaned and the barring carrier checked I use Mercury special lubricant 101 or the equivalent to grease the splines before returning, - installing the props. 

Handymans342

Well the props are clean MT LOL

Michael T

....... and, lucky you -  they'll stay that way! 

Dream_Inn

Steve, a couple coats of the Merc Phantom black will significantly help them out and make them stay looking new.  I have a can that I just touch up the bottom of mine each fall from the sand bottom touching it gets.

Michael T

That's the way to go,  then a waxing -  worked great for me on my lift and still works great in fresh water. 

diggin2day1

The previous owner of my boat has used SeaHawk Smart Solution on the bottom and outdrive(safe for both), and I used it as well in the beginning of the 2015 season. Pretty happy with the product as there was little to no growth and minimal amounts of scum. I had a new Bravo 3 installed in late August and ran the boat until the end of October without any anti-foul paint on it. When I pulled and winterized my boat the outdrive still looks excellent with some minor discoloration/growth(I can remove it and return it to glossy with just a rag and some elbow grease). My question now is what to do for the upcoming season.... Do I scuff up that beautiful shiny black and paint it with the SeaHawk? I was told that if I don't scuff, it won't adhere(sounds legit!!). 

jme097

I dont have any major problems with mine either. Just a little area from where the bottom of the outdrive touches the sand while we're anchored in the Bay. Maybe an inch from the bottom. Do you think good wipe down of cleaner and then a couple coats of the Mercury paint would be fine? I don't really see a need to fully sand all the way down for a small area. 

Michael T

Agreed! 

LaRea

Handy, you don't have a major corrosion risk with those drives.  

One reason is that they are Bravo 2 drives, which never seem to be as bad as the Bravo 3 (the poster child for outdrive corrosion).  But the main thing is that you're storing out of the water.

I'll never forget the first class I took in ocean engineering years ago.  We got a bunch of identical aluminum plates and stored them in different conditions: dry, damp, submerged in water and so forth.  After a couple months, the dry and damp plates had only light surface corrosion, but the unpainted plate submerged in moving salt water was almost gone.

That's what happens to outdrives stored in water, unless you keep up with the paint.

walleye

Here are some pics from the project. Apologize they loaded in reverse chronology. View from the bottom up!