I’m not sure who had the bright idea of polishing my prop but thats a lot of work. A friend of mine just bought a 1949 Cessna 170A with a polished prop. Well I just could not let his prop look better than mine, so I spent two days stripping mine and then polishing it. OMG that’s a lot of work. It really does look better. I will post some before and after pictures in a few days.

For those of you who have a polished prop what do you use to keep it shinny. I used mothers after the initial rubbing compound. Let me know what you guys do. Thanks.

A crop duster friend of mine always ran polished props, used paste wax on it every day when they washed the plane down. That was back during the 6/3 days. That stuff was pretty hard on paint.

I like the polished look too. It's always nice to know that if you send it in to a prop shop sometime, chances are you'll get it back anodized and re-painted. Then it starts all over again.

gb

Ummmm, ya might want to check, but I believe that painted prop might have to stay painted to be airworthy. I'm sure the gurus are gonna speak up here in a bit and tell you the regs.

Gump

I believe that you are right Gump, although I can't remember all of the details. Seems to me it was about a year and a half, or two years ago when that first came to be. I'll see if I can go thru some of my old notes and find the reg.

Interesting, I wonder why there are so many polished props out there. I actually spoke with two different A&Ps and nothing was said. If you guys can find something I would appreciate it. And the next question is what makes it not airworthy??? It would seem a polished prop is better taken care of than a painted prop. OOOOWWWW that would be common sense and we can’t have that anywhere in aviation.

From Luscombe.org

http://luscombe.org/index.php?page=prop ... -polishing


PROPELLOR* MX and (Propeller) POLISHING
A polished PROPELLER can be a thing of beauty, and is often coveted by the owners of classic aircraft. However, PROPELLER polishing may affect the airworthiness of that component.
All parts for certified aircraft are designed and then produced to a set of specifications, many of which are in the type design data sheets, and some of which are only contained in the manufacturer’s "approved" data consisting of drawings, process specifications, and manuals. Technically, only the manufacturer’s specifications for coating process and materials may be utilized. Practically, enforcement actions against anyone maintaining the PROPELLER in sound condition is a reasonable defense by the owner and mechanic.
If the owner and operator cannot provide the approved data authorizing a polished PROPELLER, he can be judged by an inspector to be guilty of altering the FAA approved type design, and thereby grounded, or the aircraft denied re-certification. Such occurrences are rare, but possible.

The web site goes into eligibility for different brand props.

Another thing to consider is glare on the backside of the prop, especially at night if you have strobes.

Gump

I used to use a small orbital buffer for polishing large flat aluminum surfaces on my semi truck. So, a buffer might work well on a prop, too. Use a liquid type polish, also. Have fun!

(1) Surface Corrosion. The loss of surface metal due to chemical or electro-chemical action with visible oxidation products usually having a contrasting color and texture to the base metal. Surface corrosion, as shown in Figures 1-1 and 1-2, generally results when the corrosion protection on a metal surface has been removed by erosion or by polishing. Therefore, removing paint and corrosion protection, such as when polishing blades, is not recommended.

Questions??????

McCauley Met-Al-Prop Repair and Maintenance Handbook, dated 2-15-55 says specifically:
14. Finish
a. If the repaired propeller is to be used in the vicinity of salt water, it shall be anodized.
b. The face side of the blades shall be painted with a non-specular black lacquer for glare elimination.
c. The tips shall be painted with red, orange, or yellow lacquer.

I agree with the nay sayers. Whether it's a regulatory risk or not, its a bad idea.

Paint, even on a prop, is designed largely to PROTECT the surface of the metal. On a prop it does so both by preventing corrosion and believe it or not, by preventing minor erosion on the leading edges. Paint erodes off the leading edges. That should tell you something.

Its better to lose a bit of paint than a bit of metal.

Further, once you strip the paint from the surface, you start removing some metal from the prop every time you polish it. Not much mind you, but it will add up over time. You expose the entire surface of the prop to corrosion as well, which will have to be removed by more polishing.....

Bad idea, and a huge pain in the butt to maintain.

MTV

Personally, I would prefer a painted prop, especially for regulatory reason's. Polishing is just a big pain in the rear !! MTV is right, each time you polish that prop, you will remove a very small amount of metal. If this story is true, one of the old Air Force One's (707 type) was put out of service because the aluminum skin was polished to it's minimum thickness.

I polished my prop on my second tripacer and my mechanic told me it wasn't legal. Anyway I left it and kept it polished for the time I had the airplane. Also polishing the back of the prop is not advisable. Leave the back side, that you look at through the windshield black. The glare off a polished prop rotating is like looking into a mirror. I kept the back of mine black...I used simichrome polish which put a mirror shine on the prop. It also removes metal which is why it shines so well. Paint is a lot easier to maintain...

pif_sonic wrote:Questions??????

McCauley Met-Al-Prop Repair and Maintenance Handbook, dated 2-15-55 says specifically:
14. Finish
a. If the repaired propeller is to be used in the vicinity of salt water, it shall be anodized.
b. The face side of the blades shall be painted with a non-specular black lacquer for glare elimination.
c. The tips shall be painted with red, orange, or yellow lacquer.

Actually yes. Paint the face flat black, but it doesn't seem to specify what is done to the other sides, except for the tips. Seems to leave polishing as an option because unless I'm wrong, no coating is specified unless near salt water.
Or am I missing something?

The face was painted in a flat black as per my mechanic prior to being placed back on the plane. The tips are painted in yellow, that was just because my plane has yellow accents not because I knew the regulation. That one worked in my favor.

I have heard some people talking about how the paint on a prop protects the leading edge. I can tell you I looked at every plane on our field and the leading edge looks bad on all of them. Now the three planes that have the props polished, not including mine, the leading edge looks so much better. I am not sure if I am missing something here or not. It just seems the polished props are better taken care of. (Maybe because they require more TLC than a painted prop) I am not talking about small dings in the prop they all have that. Well I will do what ever is right by the regs and what is best for the safety of my plane but it is nice to hear other people’s opinions.

My take on it is if you want it polished, polish it. My opinion is that you will be dead before you polish so much metal off of it that it affects it's structure. I won't polish mine, but it's because I'm too lazy, not because I believe you will change the molecular structure and the prop will fail in the future. If leading edge wear was a real problem, then it would have been discovered and dealt with fifty years ago.
Some things, I believe have to be taken with a grain of salt. For example if you take the definition of a prop strike literally, then most of us are due for a prop strike inspection.

The guys at N.W. Propellers gave me a tip on caring for the leading edge of the prop.

Since dirt and water will erode pretty much any paint you put on it the prop, the guys at NWP suggested waxing the leading edge when you put the plane away for the night. Any old paste wax seems to work fine.


This prevents corrosion from getting started in any of the micro cracks or nicks. It, of course, almost immediately wears off so you have to do it as a shut down routine.

TD

A friend noticed some very slight corrosion/pitting on his polished aluminum propellor. He did some sanding and polishing and then used this product, nuvite. Check out their website:
http://www.nuvitechemical.com/
A couple of coats is suppossed to give annual protection. I was going to try it on my polished spinner...its about the only thing that shines on my airplane.

If you are into polishing aluminum go to www.perfectpolish.com. They sell Nuvite and all other goodies to polish 180's to Airstreams.