Prop polishing – every season?

BabaYaga

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Hi all,
last spring just before launch I spent an hour or so polishing my feathering prop with a dremel tool, in an attempt to reduce the growth of barnacles during the season.
However, I didn’t bother with the hub, just polished the blades.
As the picture shows (taken just after lift out) this treatment made quite a difference.
Previous years I have tried coating with fat and heating, lanolin and plain prop fat, but with no great succes. Mainly I have relied on a mid season scrub by hand, snorkeling.
Now polishing seems to be the way to go. But does it have do be redone every season? Or could I just polish the hub next spring and be free of barnacles for years to come (sounds to good…)
Any experiences?

http://www.ybw.com/forums/images/attach/jpg.gif
 
5 minutes polishing

I polish every season
It takes me less than 5 minutes
I use a 4½ inch angle grinder with wire wheel
 
Hi all,
last spring just before launch I spent an hour or so polishing my feathering prop with a dremel tool, in an attempt to reduce the growth of barnacles during the season.
However, I didn’t bother with the hub, just polished the blades.
As the picture shows (taken just after lift out) this treatment made quite a difference.
Previous years I have tried coating with fat and heating, lanolin and plain prop fat, but with no great succes. Mainly I have relied on a mid season scrub by hand, snorkeling.
Now polishing seems to be the way to go. But does it have do be redone every season? Or could I just polish the hub next spring and be free of barnacles for years to come (sounds to good…)
Any experiences?

http://www.ybw.com/forums/images/attach/jpg.gif

I have used Prop Shield found it ok
 
I polish every season
It takes me less than 5 minutes
I use a 4½ inch angle grinder with wire wheel

With respect, that is not polishing it is scratching it clean. The whole idea of polishing is to remove all the fine scratches and leave a surface so smooth you can see to shave in it. A prop covered in scratches simply provides a nice key for fouling to stick too.
 
With respect, that is not polishing it is scratching it clean. The whole idea of polishing is to remove all the fine scratches and leave a surface so smooth you can see to shave in it. A prop covered in scratches simply provides a nice key for fouling to stick too.

+1
If the boat doesn't get used for the season and just sits, then even though you've polished , you will find the barnacles will take hold.
So, polish and use regularly to keep the prop reasonably clean, imho.
 
perhaps daft question but what do you use with a dremel to polish (son has dremel which I could borrow)

The dremel was quite new to me, so I tried to find my way amongst the various rotating bits that came with the kit. My main concern was not to scratch the surface, as I believe that would just encourage growth, just as Robin points out.
Mostly I used the felt wheels together the polishing compound. This gave a good end result, but progress was pretty slow. One hour to do just the blades is no exaggeration. I also tried the wheels that dremel call "abrasive buffs", but they wore down quickly.
There are quite a few accessories for cleaning and polishing in the dremel system, hopefully I will find a way to work in two steps with two different tools next spring.

The main reason I didn't do the hub was lack of time, only got the idea just before launching. Also thought it could be interesting to leave it, as a reference. The picture shows the difference, I think.

I agree using the engine regularly is important too. But the hub has been used as much as the blades.
 
Could someone post a definitive recipe for foul prop->shiny prop please?



Cheers Martin

Can't claim it's definitive but the process I use seems fairly easy to me.

The disclaimers for this is
1) My prop was new 4 years ago so has always had a clean surface finish so it might be easier for me.
2) Metal polishing is fairly easy if you're a hands on kind of person but I'd practice first (always wear gloves and safety goggles).
3) This is what works for me. There may be better/quicker/cheaper/safer/lazier ways of doing it for you.

For my bronze 3 bladed prop. -
. When the boat comes out it is jet washed and then I leave it for the winter - I do this as the barnacles and calcified slime dry out and seem to come off easier in the spring.
. Scrape any chunkier bits remaining off with a handy bit of wood (not a metal scraper) to avoid gouges.
. Go to work on the prop with some 180 wet and dry - GENTLY! - getting rid of most of whatever crud and surface corrosion is left.
. move up to 400/600 grade wet and dry again, gently, hand sand the blades back to clean bare metal, trying to remove the minimum whilst getting rid of deep scratches.
. After this I use some felt metal polishing wheels - this sort of thing- on a long spindle which I use with a medium and fine wax polishing compounds to get a mirror finish. Care must be taken to not bash the prop with the spinning drill chuck or spindle but it's not hard.

Last two years, after this process, I've then heated lanolin and rubbed it thickly onto the prop. before using an hot air gun to melt the lanolin on the prop. It seems to stop barnacles but I've had quite a lot of slimey weed (and ropes - see another thread) last season so it's not perfect. This year I'm going to polish but not put the lanolin on to see what happens.

Hope that helps.
 
That's certainly does help!!!


Thanks for taking the time to write such a detailed description.



Cheers m.


PS is a polishing wheel on an angle grinder too fast for this kind of job?
 
That's certainly does help!!!


Thanks for taking the time to write such a detailed description.



Cheers m.


PS is a polishing wheel on an angle grinder too fast for this kind of job?

If you can get at your prop with an angle grinder you can certainly try (I'm a full keel with transom hung rudder so no chance for me). I find the smaller unmounted felts on a long spindle allows me to get into the nooks and crannies. My little 500w drill has variable speed and weighs a lot less than my angle grinder which makes it easier.

If you do use an angle grinder with a polishing wheel, I'd use quite a mild cutting compound.
 
Last edited:
Hi again

I've been checking out variable speed gizmos (fein, dremel etc), ouch these things aren't cheap!

Has anyone seen something suitable that's a bit better value?


Cheers m.
 
Can someone dry me out behind the ears? - if I polish my prop, do I need to put a shaft anode on? My hull anode is cross-bonded to the engine and gearbox, but I think the flexible nylon connection between gearbox and shaft must break the circuit.
 
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