Not painted aluminum prop?

[59pacer]

I asked a Sensenich rep at Oshkosh this same question many years ago. His answer was 'not under any circumstances'. I suggested a clear epoxy or something similar over the polished blades--same answer.
Look nice though, don't they?

[RickF]

Yeah, I was looking for more "chapter and verse." I see where it needs a protective coating ... nothing about not polishing.

Chris

Capter and verse:

AC20/37E


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




I hope this helps.

Rick

[Jim]

Hi,

I've kept mine polished for as long as I've owned it, 35 plus years. I found the back side needs to be painted because of the earlier mentioned sun reflection. The twice a year polishing was getting old so I've tried a few things over the years. Oil, silicone, wax etc. really didn't help much. Got to thinking clear coat paint might be the answer. Polished it up and sprayed it with Awl-Grip/Alumigrip clear two part polyurethane. Blew off in large hunks early on. Since a polished prop was the goal, couldn't really use a primer. Etching was also out, but trying nothing didn't work at all. This time I polished it and wiped it down with vinegar, a mild etch. Repainted with the clear and it worked OK until flying in the rain which eroded the leading edges off. So, for me, the bottom line is routine polishing. Kind of tuff to make paint stick to polished aluminum. If I tried something again it might include clear leading edge tape too.

From what I'm reading here it's advisory or not recommended to polish, but not illegal. I thought it was. Is it?

[tferraro]

Some of the confusion on this issue comes from taking a prop into a prop shop operating under a FAA repair station. If the prop is overhauled it must be painted per the manufacturer specs. Thus they cannot overhaul and return to service with the proper paperwork unless they paint it. Hamilton Standard is one exception, there are probably more. My pacer had a polished prop and it was a lot of work to keep it polished and maintained. Corrosion is a real issue. At the last overhaul we went back to the gray paint. We also have a Stinson Reliant with a Hamilton Standard that is polished. It is really a lot of work to keep it looking like a mirror, but it is fun and it just wouldn't be right without that shine up front. I think everyone has pretty much said it in the notes, but it is not a FAA regulation, just recommendations. You would likely have a problem finding any prop shop that has a repair station certificate that would do anything but paint it.

[Tailwind_Fan]

I guess this would be the best place to post that during my annual inspection, while the propeller was off I redid the static balance, the polished it, along with the spinner
77488CE2-F2A2-41B5-A3C6-9C3F016D5F67.jpeg

[Tailwind_Fan]

Based off of my pre-annual photos, I don’t think there was any paint on the propeller from before I polished it. I’ve owned it for a year now and this is how it came... Sins of a previous owner perhaps?

D8C6B1ED-F531-4F59-BE69-A216451CE5BD.jpeg

[Old3pacer]

yours looks awful pretty!

[Tailwind_Fan]

yours looks awful pretty!

Why thank you

I worked hard to get it that way. Now I hope the Carnuba wax helps keep it that way.

-Alana

[Rotormech]

I hate to pour cold water on this hot topic, but I encourage all to read AC 20-37E dated 9/9/2005, with attention to Paragraph 205 (e) and Sensenich Service Bulletin #R-15A dated 10/4/1989, with attention to the Discussion section pertaining to the finishing of older metal propellers.

Steve P has also posted the Sensenich Repair Manual, SPRM 590 under the topic Sensenich Repair Data.


Sent from my iPad using ShortWingPipers.Org

[Glen Geller]

More on painting from our pals at Sensenich, Item 10 on the second page is of particular interest.
http://www.sensenich.com/wp-content/...1311618307.pdf

My 55 Tri-Pacer had a polished prop when I bought it over 16 years ago. I polished it several times a year with Simichrome and wiped it down with LPS2 after (almost) every flight, as the previous owner had advised (he owned it for 22 years before me.)
Several year ago at a fly-in, the fuel truck guy (owner/operator of the FBO on the field) suggested I might want to paint it.
When I delivered it to the prop shop last year for reconditioning, the shop manager raised an eyebrow and said something like, "Hmmm, polished, eh? You understand it's coming back painted, so it will be legal, OK?"

Cheers,
GG