DIY Bravo III stainless propeller polishing

[iBoat Skipper Doug]

As I’m brining this new to me boat back to life, one of my projects is painting the outdrive. This lead me to polishing the dual stainless steel propellers.

With two very small nicks in one propeller, crescent in shape and no bigger then the size I would cut off when I trim my finger nails, I took them to a prop shop. Thats when I lerned they have a one price policy, no matter how severe or minor the damage. I did not want to drop $300 to get these two minor dings fixed. During my short ride on this boat, I could detect no propeller vibration.

I talked to another prop builder, watched a few YouTube videos, then used a metal file as instructed, taking great care to never create a rounded corner on the edge of the prop. Its DIY fixed, but not yet real world in the water tested.

Next, I wanted to improve the looks. I wanted props so shiny that the fish would really be impressed. After some trail and error, I learned compound or oxidation remover had little affect. Neither did wet 120 grit sand paper. Tried a fine cup wire brush on a drill. Better but man, it was going slow. Finally tried a course cup wire on a drill. Now I was making progress. Next, I rinsed the props in water then waxed. Below are before and after photos.

Now the props are smooths as a babies ars.

Have you tried DIY or Do-it-yourself stainless steel propeller polishing? How did you do it? What were the results?

 

[Little Ducky]

I don't believe these props were ever smooth or shiny from day one.

I would worry more about prepping that outdrive and using some indestructible paint. Those BIII drives seem to corrode away right in front of your eyes.

 

[scoflaw]

I'd be more concerned about your drive and transom assembly corrosion. Make sure all your bonding wires are attached and your mercathode works.

 

[Captn TJ]

I'd be more concerned about your drive and transom assembly corrosion. Make sure all your bonding wires are attached and your mercathode works.

Yup - close-up of the anodes looks like they're in rough shape. Corrosion on the nut as well? also the outdrive with the paint flaking off looks rough as well. More work here than just the props.

 

[Lazy Daze]

What I see on the drive looks like fresh water paint-peeling/bubbling. Not necessarily true "corrosion". From what is visible, the drive looks fine in terms of the Al. The anodes are OK - maybe just brush them off - but they are mostly whole. The fwd prop nut is fine, too - it's just a natural verdigris - which actually protects the metal.

However, I agree with the above comments that your time would be better spent on refinishing the drive to protect it, than putting a slight sheen on the props. Can't tell from the picture, but I hop you didn't use a steel wire brush. In addition to the suggestions above about bonding, also verify that you have the right anode composition for your waters... Al or Mg... Al is safest bet.

 

[iBoat Skipper Doug]

Yup - close-up of the anodes looks like they're in rough shape. Corrosion on the nut as well? also the outdrive with the paint flaking off looks rough as well. More work here than just the props.

Thanks guys. The drive is a separate topic, but I’m addressing that as well.

Please keep in mind, this is a 15-year-old, $15,000 boat I am bringing back to life on a budget with ordinary tool box tools. Also, this boat will spend its life on a trailer, not in a marina as the previous owner kept it except for the last few years when the boat was in storage due to the previous owner having health issues.

Best would be to drop $12,000 and stick on a new drive, right? But that wouldn’t be practical.

Second best, remove the drive, get it soda blasted, and professionally repainted. Still a $ grand plus.

Option three, DIY for about $50 bucks.

Knowing I can re-do this myself as needed, I’m going with option three.

Similar to the propellers, I sanded the drive, cleaned it with 216, taped it off, used one can of mercury primer, first paint coat is done and I’m about to add the second coat of phantom black paint using a shaker paint can. The drive has some pitting, but I have removed all aluminum corrosion. This painting will be followed by new magnesium anode‘s and I will add the additional center prop anode.

I'd be more concerned about your drive and transom assembly corrosion. Make sure all your bonding wires are attached and your mercathode works.

Test the mercathode system on a trailer boat without shore power? Really?

 

[Little Ducky]

Holy crap I didn't realize it was 15 years old....... Looked pretty good.

My B3 looked worse then yours after 3 years in water 24/7/365

 

[dan313]

Hi,

When you put your props back on they need to be timed. Place the first prop blade in a down position. when you put the second one on. The prop blade is in the up position. I was told this by a Merc Mechanic. He said that if you don't do it this way you can have vibration in the props.

 

[Stee6043]

I've tried the rattle can method a few times in a past life. The general consensus within my "circle of trust" would be that you paint the out drive to sell it. Otherwise...well...you may see next year how long that stuff holds on

Cool set of projects. You're certainly keeping busy. And for whatever it's worth 15 years old is not that old in the grand scheme of things....you're just further down the depreciation curve than some others.

 

[iBoat Skipper Doug]

...... You're certainly keeping busy.....you're just further down the depreciation curve than some others.

Thank you. This outdrive project, combined with about 30 other boat projects, all done DIY, will hopefully temporarily reverse the boat value deprivation curve.

Soon I wil be cutting my dash, relocating some gauges, then adding a flush mount chart plotter and VHF radio. I’m pretty excited about that project. I haven’t seen a 225 Weekender with a flush mount GPS Charplotter. There is just enough room left of the wheel once I relocate the starter switch, depth guage, and remote radio controls.

I shopped for over a year before I purchased this boat to the point that I think I became anoying to some local dealers who sell brokered boats.

Boat owners who have their boats listed for sale are difficult to figure out.

During this boat shopping time, I found clean boats maintained in good order sold at a premium price and sold fast.

Some poorly maintained and dirty boats have, in my opinion, unrealistic seller valuations by the owners. These are the boats that dont sell for months, or even years. I had made multipe offers that were rejected. Oddly, since buying this boat, two private boat sellers called me back asking if I would still take their boat at the price I had offered them a few months ago.

In the end, I’m glad I got this exact boat. The only unexpected item that needs repair that I did not find during my evaluation is the outdrive power trim down solenoid is only working intermittently. I’ve ordered Starter Tilt Trim Pump Relay Solenoid for Mercruiser 89-96158T for a bout $20 and will put it in after it arrives.

 

[iBoat Skipper Doug]

...When you put your props back on they need to be timed...

Thank you Dan.

Although official MerCruiser instructors do not instruct mechanics to “Phase” props such that when one blade is at 12 o’clocs, the other propeller has a blade at 6 o’closk during installation in their certification class, Volvo does teach this technique to reduce ventilation (not to be confused with cavitation) during sharp turns as the drive is trimmed at proper running level for straight operation.

It costs nothing to phase the props during installation. I will be phasing my propellers as I reinstall them.

With bizare conscience, I was discussing this technique with Jim Maretn in Oshkosh yesterday, who is one of the best racing prop tuners in the country. I will be making a vidoe about him sometime this fall / winter. In a recent LOTO shootout, 4 of the 7 winners used props Jim tuned.

Thank you for the reminder.

 

[Stee6043]

FWIW I think your proposed location for the chart plotter is too low. Particularly for the size unit you can fit in that space. I'm imagining you'll be hunched over trying to manipulate and read that while under way. Not ideal, potentially unsafe?

Have you considered a ram-mount style attachment elevated above the dash or attached to the window? Don't let the sexiness of the flush mount impact the usefulness.

My two cents only...

 

[Leardriver]

Those props look great.
I bought some horrible looking B3 props off of Ebay from a boat that was moored in the Gulf. Barnacles, ugly stick corrosion, but perfectly true. I think I paid $250 for the pair. I took them to a local glass bead blasting shop, and in 20 minutes and $25 bucks, they looked brand new. Good gamble.

 

[iBoat Skipper Doug]

FWIW I think your proposed location for the chart plotter is too low. Particularly for the size unit you can fit in that space. I'm imagining you'll be hunched over trying to manipulate and read that while under way. Not ideal, potentially unsafe?

Have you considered a ram-mount style attachment elevated above the dash or attached to the window? Don't let the sexiness of the flush mount impact the usefulness.

My two cents only...

Thank you for your feedback. I respect your ideas and suggestions. We may see it different, and there is nothing wrong with that.

I’ve owned a larger boat with dash mounted radar and ram mounted chart plotter and I didn’t like it. First, the radar screen was in my sight line when sitting. I had to stand at the helm almost all the time. Second, I find the flush mounded installation looks better, more professional, adds a bit of class and sophistication, or sex-appeal as you pointed out. I admit looks are a personal preference thing.

As far as functional, well, I can sit or stand at the helm and see to operate the depth gauge and radio remote. So I think I will be able to see and operate the chart plotter in its intended location.

I’ll chalk this one up to strong personal preference. So strong that I pre-measured the dash for flush mounted electronics before I made my offer to purchase. If it would not have worked to flush mount, I would not have purchased this model. As you can tell, I really want flush mounted electronics.

For me, with my tastes, intended use and budget, this 225 Weekender is the perfect boat at the perfect price point. I’m getting the reliable, catalyst-free 5.7 liter GM small block with MPI, a combination my mechanical experience helps me understand, a Biii with its ability to pop on plane or pull kids, a very large, open swim platform that sticks out past the running gear, typically only found on a much larger cruiser, so large the grandkids can safely play on it til the sun sets, a Bimini + extended camper top with full enclosure that will allow us to extend the boating season to include days with rain, cooler temperatures, or too much sun, a little cabin for afternoon naps for the grandkids and kids at heart, a porta-potty for kids and girls, all that in a boat that gives me the freedom of towing on a aluminum trailer with a modern mid-size pickup truck, oh, and brand spanking new navigational and communication electronics.

Looks / styling is a personal thing. I’m drawn to the early 2000 Sea Ray express cruisers.

Normally, small boats are envious of big boats for their size and creature comforts. In my case, I am envisioning big boats being envious of my little boats comparative simplicity and crossover vehicle like flexibility.

Thank you again Stee. All ideas welcomed.

 

[iBoat Skipper Doug]

.... Can't tell from the picture, but I hop you didn't use a steel wire brush...

Thank you for your question Dennis.

The wire wheel packaging does not say what it is made from, but I’m going to guess brass. I did start with a much milder alternative then went up in abrasives one step at a time until I found one that worked.

To the touch, the propellers are smooth. No scratches. Wax made them shine.

I’m telling you, if I use this boat for fishing, the fish are going to be drawn to my boat just so they can see themselves in my propeller blades.

 

[scoflaw]

Thank you for your question Dennis.

The wire wheel packaging does not say what it is made from, but I’m going to guess brass. I did start with a much milder alternative then went up in abrasives one step at a time until I found one that worked.

To the touch, the propellers are smooth. No scratches. Wax made them shine.

I’m telling you, if I use this boat for fishing, the fish are going to be drawn to my boat just so they can see themselves in my propeller blades.

Dude, your out there. Flower child in your day, no doubt

 

[iBoat Skipper Doug]

Dude, your out there. Flower child in your day, no doubt

Thank you scaflaw... I think

 

[iBoat Skipper Doug]

Sanded, cleaned, taped, primed, painted, painted again, new anodes, polished and touched up the propellers, reinstalled phased propellers.

Well, my center prop magnesium anode has not yet arrived, but other then that, this project is complete.

Now onto about 29 other projects I have lined up for this boat.

 

[scoflaw]

Decal looks good. Close up pic would be nice

 

[Creekwood]

Thank you for your question Dennis.

The wire wheel packaging does not say what it is made from, but I’m going to guess brass. I did start with a much milder alternative then went up in abrasives one step at a time until I found one that worked.

To the touch, the propellers are smooth. No scratches. Wax made them shine.

I’m telling you, if I use this boat for fishing, the fish are going to be drawn to my boat just so they can see themselves in my propeller blades.

If the brush was brass it would have done nothing to polish the stainless. Its likely mild steel brass plated to prevent wires from rusting. So you have probably contaminated the surface of the props with steel that will rust and will actually start the stainless surface of the props rusting too. You will see that if you get any rust forming at all. The fix is a proper prop shop sanding/polishing which is probably not that much money. So if you start to see rust, take them off before the surface pits.