Stern Drive Cleaner?

hyperlite33

hyperlite33

New Member
Feb 5, 2011
15
Colorado
Boat Info
2009 Sea Ray 185 sport
Engines
4.3l 190hp
Was wondering if there was a product out there for cleaning the black paint on the sterndrive? My Mercruiser black paint has really bad "water stains" that make the paint look cloudy and really old. I have tried simple green and it takes a lot of elbow grease to get it to come off.
Any other easier solutions for this? :smt100
 
hyperlite33 said:
Was wondering if there was a product out there for cleaning the black paint on the sterndrive? My Mercruiser black paint has really bad "water stains" that make the paint look cloudy and really old. I have tried simple green and it takes a lot of elbow grease to get it to come off.
Any other easier solutions for this? :smt100
Click to expand...

I normally use repeated applications of Simple Green with a brush then sand where needed for corrosion spots, prime and repaint. If you choose to re-paint, the Phantom Black paint and Light Gray Primer are both readily available at West Marine. My drives sit in the water all year and I have never had the types of stains you describe but that could be anything really depending on the water.

I am sure there are some other solvents you could try but I will abstain from mentioning them because they could possibly make it worse. I'll leave that suggestion for someone has tried them.

Jason
 
Try some rubbing compound made for clear coat finishes.
 
Without seeing pictures of the drive it is difficult to determine the best course of action. Rubbing compound will probably work but that is a lot of work. I would first try a Mr Clean Magic Eraser to see if that helps out.
 
jason78 said:
I normally use repeated applications of Simple Green with a brush then sand where needed for corrosion spots, prime and repaint. If you choose to re-paint, the Phantom Black paint and Light Gray Primer are both readily available at West Marine. My drives sit in the water all year and I have never had the types of stains you describe but that could be anything really depending on the water.

I am sure there are some other solvents you could try but I will abstain from mentioning them because they could possibly make it worse. I'll leave that suggestion for someone has tried them.


Jason
Click to expand...

My boat has only 40 hours on it and is trailered everywhere, so I hope I don't have to repaint any of the motor! The stains I believe are from the water we have at the house when washing it down as it is real hard water and leaves a hard water residue. It's hard to see when washing, cause when it is wet it looks fine...dry it looks horrible.

tbirdvet said:
Try some rubbing compound made for clear coat finishes.
Click to expand...
I have had two different people recommend that, but they aren't boat people, so I was cautious trying it. Maybe I'll head to the auto parts store tonight and see if I can find some.
 
Last edited:
I can't guarantee any of this, but some ideas:

CLR
Slimy Grimy or On & Off
Muriatic acid or a product called Acid Magic
 
I have used liquid toilet bowl cleaner (the Works) and it has worked nicely - slightly acidic and it did not etch the painted surface - put on a brush, scrub, and promptly rinse.
 
Here's two suggestions....

1. Lysol Power Toilet Bowl Cleaner (gel form) - It's 6% hydrochloric acid. Put latex gloves and safety glasses on, apply to outdrive, spread around with your hands, let sit for 5 mins, scrub with brush, rinse with water. You will be amazed at the results.

2. If that doesn't remove it, try muriatic acid found at either Home Depot or Pool Supply Stores. Usually it's found in 10-13% hydrochloric acid strength for homwowner use.

I have always found the toilet bowl cleaner to work wonders as goofy as it sounds. It even works well on the getcoat at the water line.

Doug
 
A diluted solution of muriatic acid works great. The water out here is more calcium than h20 so I know exactly what youbare talking about. I diluted the acid 3:1 in a garden sprayer, sprayed the drive and let it sit a few seconds, then hosed it off. Repeat this process until all the hard water stains are gone.

Wear gloves, long sleeves, and eye protection. Also be very sure to rinse very thoroughly.
 
I would agree with the muriatic acid, but first try some CLR. The hard water stains should come right off. No need for rubbiing compound from what you are describing.
 
Thanks guys for all the ideas! I think I may have a bit of CLR left, but I am going to try the toilet bowl cleaner first. I'll update in case someone else might have this problem.
Thanks!
 
I just painted mine. I have a wood shop in my basement, so solvents are a regular stock item for me. After sanding the chipped portions of my skeg, I reached for the closest can and got mineral spirits. I put some on a rag, and wiped the entire drive down. I maksed off and painted the lower unit. When that dried, I masked off the lower unit and again, reached for the closest can of solvent, which happened to be lacquer thinner. I wiped the upper half with it and noticed that the cloudy stuff came off where it had been wiped with the MS in the prior step but not in the untouched areas. I grabbed a second rag, and put some mineral spirits on it. Alternating between 2 rags, one wet with mineral spirits, and the other wet with lacquer thinner, removed all of the scum on the drive.

Use Neoprene disposable gloves, as the latex ones will be disolved.
 
Just wanted to update the fix that finnaly worked on the crusted on water stains. Since reading the toilet bowl cleaner cautions on the label and found it is similiar to handling nuclear waste, I decided to try the CLR first. It started to come off with the CLR, but took a lot of scrubbing with a brush and rag. I then went to the toilet bowl cleaner...squirted it on, waited a minute and then hosed it off to find a sparkling clean like new engine!
Thanks for the help guys! :thumbsup:
 
So what brand of toilet bowl cleaner did you use. Need to prep mine for replainting with anti-foul paint again.
 
Does your stern drive have a chalky white film or the paint is discoloring on it? If so that means the casing of the drive is so hot it is boiling off the water that is splashed onto it while you're cruising or plunged into cool water when your boat comes off plane. Your stern drive is probably operating at 250 + degrees. Image how thin the oil must be and how soft the internal components are at that temp! Motor vehicles don't even operate that hot.

Tests have shown that cooling with a drive shower can double the outdrive life and service life of the drive oil by lowering the operating temperature by a minimum of 30%. It prevents oil foaming, the main cause of oil breakdown.

Mercruiser outdrives are notorious for these problems starting with the hottest running Bravo III. The Bravo III's have problems keeping oil in the reservoirs which is due to excessive heat. This heat is thinning the oil so much that the seals start seeping.

By installing Drive Shower you can dramatically reduce the temperature and wear and tear on that overworked outdrive. This efficient cooling system picks up the water from 2 direct flow water intakes, just below the cavitation plate, behind your prop, and dumps the water at the top and side surfaces for the greatest possible heat dissipation.
 
Muriatic acid is great but, if the paint is scratched through to metal it WILL eat the aluminum.
Careful..
 
Cincy Aquaholic said:
So what brand of toilet bowl cleaner did you use. Need to prep mine for replainting with anti-foul paint again.
Click to expand...

I just used a cheap toilet bowl cleaner from my local "Dollar Tree" dollar store. I think they are all the same nasty stuff.

boater4life said:
Does your stern drive have a chalky white film or the paint is discoloring on it?
Click to expand...

My stern drive is the chalky stains that are pretty common in my area due to the minerally hard water.
 
You must log in or register to reply here.

Forum statistics

Threads
113,183
Messages
1,428,110
Members
61,091
Latest member
dionb
Back
Top