Burnishing the propellor

[DoubleEnder]

What's the best way? I have a powerful cordless grinder, M14 and runs at 8000 rpm. fixed speed. But I dont seem to be able to find a fitting that will allow it to be used as a polisher. Do I really need to buy a dedicated polisher? Is there something I can use in a drill, maybe? The boat's in the shed so I have access to 240v as well. I'd prefer not to buy a polisher as I have no use for it other than this

Thank you

Graham

 

[johnalison]

I have a mediaeval rubber disc for a drill which I fit with a lambswool pad for occasional jobs like this. I haven't looked, but I don't see why they shouldn't still be available.

 

[Quandary]

Sometime back in the distant past I acquired a coach bolt with several hundred cloth discs tightly threaded securely on to it, about 3" dense layer, used annually in a power drill chuck to burnish the prop. A lot more abrasive than lambs wool but ideal for polishing bronze. You do have to be careful to keep the spindle away from the metal. I presume it has worn down a bit but not noticeably. I have been watching out for another but I suspect the one I have will now see me out.

 

[Blue_mischief]

Genuine question - how much difference does burnishing the prop make.? I ask because my prop is quite bumpy with repeated coats of trilux - which does keep it clean.

 

[Aja]

Called polishing mops. Can be had from here amongst other suppliers...
https://www.abrasive-systems.co.uk/polishing-mops-compounds.html

Donald

 

[Quandary]

Called polishing mops. Can be had from here amongst other suppliers...
https://www.abrasive-systems.co.uk/polishing-mops-compounds.html

Donald

Great, that is the thing, I do not really need another one though but if you like your bronze shiny it is the way to do it.

 

[solent clown]

you can get polishing mops for bench grinders too, some people find it easier to hold the workpiece rather than the tool.

 

[DoubleEnder]

I dont really want to buy another tool such as a bench grinder or polisher, so I will go with the thing that fits in the drill chuck

Thank you

 

[Bunym0b]

i like the idea of a shiny propeller, will there be any galvanic reaction to a bronze propellor in sea water?

 

[zoidberg]

I dont really want to buy another tool such as a bench grinder or polisher, so I will go with the thing that fits in the drill chuck

Thank you

I did this job a while ago, and I used an angle grinder initially. That was a bit OTT, so I switched to using a flap disc on a power drill, and a couple of other cheap burnishing discs from Screwfix. I found it much easier to secure the power drill in a cheap holder by Wolfcraft, and offer the prop up to the rotating disc. That way, I could better control the degree of 'aggression' and the effect.

I also used leather workmen's safety gloves and safety goggles, having learned the hard way.

 

[Daydream believer]

Cleaned the prop with brick cleaner then went over it with a fine nylon pad for 10 mins . Perfectly good enough finish.

 

[mlines]

Or go to your local metal polishing specialist (non- marine industry!) and £20 per prop.

 

[Bunym0b]

a joy to behold

 

[Neeves]

I also used leather workmen's safety gloves and safety goggles, having learned the hard way.

It is a sad comment, me too - we all know the dangers but we all think we know best - until you take a bit out of your knuckle with an angle grinder. Reality then sinks in and we use what we knew in the first place.

 

[vyv_cox]

i like the idea of a shiny propeller, will there be any galvanic reaction to a bronze propellor in sea water?

The vast majority of fixed propellers are manganese bronze, actually a slightly modified 60/40 brass. It is therefore susceptible to dezincification. Only Nibral and some after market folding and feathering types are actually made of bronze.

There is a galvanic reaction between any of these and a stainless steel shaft and with any pivot points in their construction. This is what your shaft anode is protecting, aided by the Props own anode if it has one.

 

[Quandary]

I have just bought a Flexofold, they say it is 'nickel aluminium bronze' is that good stuff or rubbish?

 

[Iain C]

My efforts a few years ago...

 

[Norman_E]

i like the idea of a shiny propeller, will there be any galvanic reaction to a bronze propellor in sea water?

If it really is bronze it is likely to be higher up the galvanic scale than anything nearby, but in any case it should have an anode either attached to it, or on the shaft. A lot of propellers seem to be "Admilralty Bronze" which is in fact a copper-zinc alloy, and therefore brass not bronze. Such propellers should always have a pure zinc anode if in seawater otherwise they are liable to lose zinc by galvanic action.

 

[vyv_cox]

I have just bought a Flexofold, they say it is 'nickel aluminium bronze' is that good stuff or rubbish?

Nickel aluminium bronze is perhaps the best propeller material available. However, experience posted here and elsewhere raises doubts that they are what they purport to be.

 

[Tranona]

I have just bought a Flexofold, they say it is 'nickel aluminium bronze' is that good stuff or rubbish?

Can only speak for my now 7 seasons old 2 blade (without anodes!) which is as new. Coated in Trilux from new, and twice dipped the blades in brick cleaner to remove old paint and redo with primer and top coat. Hub just needs a clean up and new topcoat every year.

Don't think the material has changed on the 2 blade, although they have now added anodes.