Polishing propellors

[benjenbav]

Brick cleaner + brillo + elbow grease?

Or is there a better way?

Previously posted by mistake in The Lounge until "warned off" for boatiness

 

[carlton]

Yep - used B. & Q.'s brick cleaner on my S.S. props and they came up a tasty treat, although slightly discoloured.

You shouldn't need a brillo pad or any elbow grease either.

 

[benjenbav]

Cheers. I like the bit about no elbow grease.

 

[U4]

Yep - used B. & Q.'s brick cleaner on my S.S. props and they came up a tasty treat, although slightly discoloured.

You shouldn't need a brillo pad or any elbow grease either.

I'll second that (although mine didnt end up slightly discoloured).

 

[duncan]

I find that without the brillo bit the green stuff seems to key into the acid steel way to well!

tried that red lanolin based stuff after step 1 but it's useless on HS steel props - I have no doubt that correctly applied to bronze props it's great but it's no good on SS.

you can't beat a polished finish

 

[aquapower]

For bronze props I use a wire wheel in a 4-1/2 inch angle grinder, removes all scale without removing metal

 

[Assassin]

Never use a mild steel wire brush on anything other than mild steel propellors as it can cause corrosion as fragments of steel break off into any surface imperfections. Instead use a nylon pad on a backing pad, on a small angle grinder; these are cheap and washable and are what the industry use to finish stainless and brasses/bronzes.

These are available from engineering suppliers and available in differing grades suitable for stainless and much softer alloys or brass.

 

[carlton]

I've used these screwfix grit-impregnated nylon brushes in the past, but brick cleaner is a whole lot easier to use.

 

[Assassin]

Unfortunately any chermical cleaners not specifically designed for cleaning the particular material can create long term problems as they are mormally corrosive, and based upon acid or alkali formulations. It is the discolouration which is showing a problem is occuring within the metal itself, usually this is through the microscopic pitting of the surface of the prop, and the attacking of the deeper recesses of the material.

Using the nylon pad on an angle grinder is much kinder and will ensure the metal is not attacked, you could always lacquer the surface of the propellor as this is resistant to chemical attack. Use a good lacquer designed for car wheels, this is formulated to prevent attack from cleaners and also have alkali based cleaners used on it.

 

[Trundlebug]

Another alternative is Cillit Bang used on a sponge scourer or green scotchbrite pad.

I believe the brick cleaner is Hydrochloric acid, and the Cillit is Phosphoric acid.

Cillit is very effective but a bit kinder to the metal - note that it's very effective on stainless steel sinks so is clearly compatible for use on that material.

I've also used sponge scourers with rubbing compound like Farecla G3 or similar, and that works really well too. Used with a drill and a rotary pad it would largely take the elbow grease element out, although to get in the fiddly bits you'd still need to do it manually.

 

[Assassin]

This is where confusion enters, what type of cleaner and what type and grade of material is the screw made from? domestic cleaners are generally fine as they are far less chemical biased as their strength is so low when compared to industrial cleaners.

The message is beware on your chosen cleaning product, check, and double check if it is safe for use specific material type.

 

[carlton]

This is where confusion enters, what type of cleaner and what type and grade of material is the screw made from? domestic cleaners are generally fine as they are far less chemical biased as their strength is so low when compared to industrial cleaners.

The message is beware on your chosen cleaning product, check, and double check if it is safe for use specific material type.

If it helps at all, retired chemist of this very parish VicS reckoned the brick cleaner I linked to would be fine with S.S. - and he appears to have been right. Although, where chemicals are involved he usually is.

 

[benjenbav]

Thanks all, really appreciated. I decided in the end to do it with the chequebook as I am a bit tied up over the next few days and the boat's due to be relaunched at the start of next week.