dirty High 5 SS prop

[1979 Quartermasters]

Hey Guys,

I left my boat in the water most of last summer and was able to get most everything clean, except for the prop. Tried toilet bowl cleaner and oxalic acid to no avail. Hope I didn't etch it. I like it to sparkle. Any ideas to get that off. Very thin layer, but hard as a rock.

 

[Sea Rider]

Soak prop in pure vinegar for some hours, polish with Dremel 's SS brushes along extreme patience..

Happy Boating

 

[alldodge]

I have used CLR and such and it does help. Using a steel wool or wire wheel scratches the prop and it will rust on the surface. Need stainless polish and a buffing wheel, it gets messy (and the reason I no longer do it)

 

[82rude]

What in the world does the peg have in the water to messup a ss prop?I keep mine clean and shiny with never dull and elbow grease.You could try buying a few litres of coke and submerge the prop in that for awhile.

 

[dingbat]

Jewelers rouge, a buffing wheel and lots of elbow grease....my prop shop buffs the my prop as part of their bi-annual balance and inspection routine

 

[82rude]

What is jewelers rouge dingbat?

 

[1979 Quartermasters]

I have these green Scotch Bright pads. They take it off quite nicely. Are these to aggressive for the stainless steel.

 

[Chris1956]

Gee, SS is real strong, and scratch resistant. Try some hand sandpaper. Start with 80/100 grit and see how she goes. Finish with 150/220 grit and she will sparkle. You will not be able to remove any noticeable metal, or make any significant scratches.

 

[jimmbo]

What in the world does the peg have in the water to messup a ss prop?I keep mine clean and shiny with never dull and elbow grease.You could try buying a few litres of coke and submerge the prop in that for awhile.

A lot of lakes in Saskatchewan and Manitoba have a high Alkali content(usually Potash) which can take galvanic corrosion to a new level

The OP stated he had tried Toilet Bowl Cleaner, if it was an industrial variety, it would have been a much stronger acid than Vinegar, Coca Cola, or CLR. Perhaps a metal polish like Brasso...

Edit: Looking at your Avatar, if that is your lake, it doesn’t have the lovely white shore of an Alkali lake

 

[1979 Quartermasters]

These green pads I mentioned earlier, take it off with little effort. AllDodge mentioned I might scratch the prop and I was wondering if these pads were too aggressive?

 

[porscheguy]

You have to make that call yourself. I would say you have little to worry about. Stainless is pretty hard and scotchbrite is pretty mild. It certainly won’t leave deep gouge like scratches in it.

 

[alldodge]

Props are stainless but not made from 316 stainless. The stainless when buffed will not rust, but if you use sand paper or wire wheels and do not reseal (so to speak) with buffing compound it will start to rust a tad. Never seen green pads or scotch bite pads do any harm

 

[1979 Quartermasters]

Awesome.

Thanks Guys.........

 

[Chris1956]

"reseal" stainless steel??? Never hear of that. Stainless is homogeneous, as is all cast metal. I never heard of, or saw any coating on the surface of a SS prop. Some had paint, but that was all..

 

[jimmbo]

In the early days of SS props OMC did coat theirs with Teflon, probably to hide any rust staining, and SST(Stainless Steel Teflon) was also used for the anticipated Super Sonic Transport planes, so it implied great speed.
My QSS(Quicksilver Stainless Steel) for my Mercury had a Satin Finish, whereas my RAKERs and my Enertia have a very chrome like finish

 

[alldodge]

Its not reseal as I said "so to speak". Try it for yourself, Take a wire wheel to your prop and then see if its doesn't start to rust. Maybe its because the tiny bits of wire that come off and embed in the prop, maybe something else. Just stating what I've seen happen over the years

 

[dingbat]

"reseal" stainless steel??? Never hear of that. Stainless is homogeneous, as is all cast metal.

I’m with you on the sealing thing but stainless, or any alloy for that matter, is far from being homogeneous. Composition and density can and do vary wildly from 1sq. Millimeter to the next on rolled material. Cast materials are off the chart.....horrible

Rust “staining” of stainless is the result of trace deposits of fe(iron) getting trapped/imbedded in the material from a prior machining, grinding or finishing processes.

Once complete, the parts/material is passivated (acid bath) to remove trace deposit of fe to prevent ”staining” in the future.

Not passivating the material during production is the major cause of staining of commerical products.

Cutting, sawing, grinding etc. passivated material with a tool or brush containing fe will reintroduce fe to a passivated surface.

If you must “brush” stainless, the use of a brass or bronze brush is highly recommend

 

[Chris1956]

Gee, there are many different formulations of stainless steel. Wikipedia cites 37 different kinds.

The amount of steel, chromium, nickel, Molybdenum (and other metals) vary in each type of SS to provide different amounts of strength, and rust resistance, balances against brittleness and malleability.

Each type of SS is used for specific purposes, to maximize it's qualities against the job requirements.

There is no need for coating or sealing of SS props, as the type is SS used is chosen for that purpose.

It should be noted that galvanic corrosion of a boat with a SS prop used in saltwater is greater than that of the same boat with an aluminum prop, so anodes should be checked more often.

SS props can be painted, but most manufacturers leave them shiny, likely as some sort of advertising.

 

[dingbat]

Gee, there are many different formulations of stainless steel. Wikipedia cites 37 different kinds..

Wikipedia, my first source of industry information...lol

Been in the industry for 40 years dealing with metallurgy, alloying and quality control. Have worked with very major producer of steel and aluminum alloys the world at one time or another.

Currently working with a customer that produces over 100 martensitic, austensitic, ferritic and duplex (stainless) alloys alone. These are production alloys. This doesn’t include the one of proprietary and research heats done on a regular basis.

 

[1979 Quartermasters]

Turns out toilet bowl cleaner worked great. Very little effort with green Scotchbrite.