Stainless Steel propellers - Polish or Antifoul

[Nigel52]

Previously with a sailboat I cleaned and antifouled my propeller. On my RIB and day boat with outboard no issue as propeller out of the water. Currently have been surprised how my stainless steel duo props on an outdrive leg have got so fouled this last season despite a mid season power wash and over the side clean in July & August.

I want to keep the boat in the water and in use April - end of October and need to keep propellers clean otherwise speed drops off by circa 10 knots and fuel consumption jumps.

Would people suggest polishing right up or clean and antifoul. (Planing boat with top speed circa 24 knots and cruising at 28-20 knots)

 

[QBhoy]

I personally wouldn’t ever think about putting anything on a stainless prop. Precision engineered and finished thing really. Be a shame to loose its efficiency with paint. But I get the other side of the story too. You’d think any growth would find it hard to hold onto a finely finished surface like that, once underway perhaps. Anything on it should come away perhaps ?

 

[Nigel52]

I personally wouldn’t ever think about putting anything on a stainless prop. Precision engineered and finished thing really. Be a shame to loose its efficiency with paint. But I get the other side of the story too. You’d think any growth would find it hard to hold onto a finely finished surface like that, once underway perhaps. Anything on it should come away perhaps ?

Well I’m currently polishing them both up and hope that this works for next season. As this was my first season with this type of I was keen to get other’s experience.

 

[SC35]

I personally wouldn’t ever think about putting anything on a stainless prop. Precision engineered and finished thing really. Be a shame to loose its efficiency with paint. But I get the other side of the story too. You’d think any growth would find it hard to hold onto a finely finished surface like that, once underway perhaps. Anything on it should come away perhaps ?

It doesn't.

Mine stayed in reasonable shape for a few months, but got horribly fouled mid-season and I had to spend an hour or so in the tender removing it.

 

[Nigel52]

It doesn't.

Mine stayed in reasonable shape for a few months, but got horribly fouled mid-season and I had to spend an hour or so in the tender removing it.

Was that polished or antifouled?

 

[jon and michie]

My old stainless props used to take me an hour each to clean after a season - when I got a new set a couple of years ago volvo must have put a coating on as it took less than 15 minuetes to wash them both.
Something like this Brava Clear Antifouling Leg/Propeller 250ml – IBS Boat Supplies

 

[Nigel52]

My old stainless props used to take me an hour each to clean after a season - when I got a new set a couple of years ago volvo must have put a coating on as it took less than 15 minuetes to wash them both.
Something like this Brava Clear Antifouling Leg/Propeller 250ml – IBS Boat Supplies

Have you tried this antifoul as would be good to know from user experience.

 

[QBhoy]

It doesn't.

Mine stayed in reasonable shape for a few months, but got horribly fouled mid-season and I had to spend an hour or so in the tender removing it.

Did the growth remain even after a good run out on her, with the throttles open ?

 

[SC35]

Did the growth remain even after a good run out on her, with the throttles open ?

Earlier in the season, a blast across the Solent would clear the fouling.
But the stuff that attached later in the season didn't seem so willing to fall off.

 

[Nigel52]

Earlier in the season, a blast across the Solent would clear the fouling.
But the stuff that attached later in the season didn't seem so willing to fall off.

Similar for me.

 

[QBhoy]

Earlier in the season, a blast across the Solent would clear the fouling.
But the stuff that attached later in the season didn't seem so willing to fall off.

Can imagine. It’s a tough one eh. Likely not an option for most…but sitting near a fresh water river estuary with suitable tide state for a wee while can drop growth fairly effectively. Quite amazed at the effect of it.

 

[ss2016]

I clean mine once a year with brick cleaner. It's diluted HCl basically. The SS props get jet washed when the boat comes out but mostly its just some reddish growth near the center and a few tube worms on the hub. So, rubber gloves, glasses and rub it on with a bit of old towel. Wash the blades thoroughly after. I don't try to get them looking like new, just clean. It takes perhaps 20 mins for 7 blades on a pair of contra props. I do a few longish 4hrs trips at 23 or 24 kts. That probably helps. Even when dirty it seems to be more cosmetic than a performance issue. I don't think I loose more than a knot.

 

[jon and michie]

Have you tried this antifoul as would be good to know from user experience.

I havent to be honest - I was going to get some this winter but a change in circumstance has prevented this.
what I can say is the coating that was on my newer set was clear like the one in the link that I posted earlier.
I did ask volvo about the coating but they didnt reply

 

[ST840]

As growth only appears when in sunshine (well it's worse when), could you not trim up and fit a prop bag to keep them out of the sunshine??

Extra Large Propeller Bag - West Wales Marine

 

[limecc]

I wonder why nobody thought of electroplating their prop in copper?

 

[DavidJ]

I wonder why nobody thought of electroplating their prop in copper?

Interesting point and good thinking out of the box.
However I think the extra electrical conductivity that copper would bring may cause other problems.
Hull copper treatment on GRP is insulated from this.
Do people use copper on metal boats ????

 

[tico]

I think (and VicS is the one to know) that as Cu is lower in the electrochem series than Fe, your steel hull would rapidly fizz away.

 

[limecc]

I think (and VicS is the one to know) that as Cu is lower in the electrochem series than Fe, your steel hull would rapidly fizz away.

Isn't that what anodes are supposed to prevent?

 

[DavidJ]

Just looked up electrochem series for my education and I see that Al is below Zn. In the US I see a lot of Al boats as tenders and lake fishing boats, they must really fizz away if left in the water.

 

[ChromeDome]

Anything submerged, especially near the surface where the sun will bring light and higher temperature, will foul.

If the goal is to prevent growth on propellers I can see two ways:

1: Use the boat more frequently
2: Apply antifouling

#2 brings a challenge: Get it to stay on for a full season.

Of the many products I have used (even unorthodox) over 5 decades and 7 boats, the best result has been Hammerite Special Metals primer with Velox on top.
Held up pretty well on current boat, pushing 7½ tons at 24 knots (now and then,- not all the time) ?