The International Cessna 170 Association

Got the urge to repaint the prop. What was the original color and patter for a 1956 model?

The prop was polished aluminum, with angled red tips with Mac Cauley decals in the center of the blades. Repros of the decal are available from Moody's Aerographics or Chief Aircraft.

If you have a Hartzell, I'd recommend against polishing it like the previous owner of my airplane did. The Fuzz handed him a fix-it-ticket so when I bought the airplane the 300 hour total time prop had 100 hours since overhaul. Overhaul was the only way to bring it back into spec--and I also got a nice non-AD hub out of the deal.

russfarris wrote:The prop was polished aluminum, with angled red tips with Mac Cauley decals in the center of the blades. Repros of the decal are available from Moody's Aerographics or Chief Aircraft.

Polished, or just satin finish anodized aluminum? I don't remember any production fixed pitch MacCauley propellers of the era being polished. Please correct me if I'm wrong.

A quick search of 'polished propellers' on this forum points to previous topics on this.
One post in particular

Polished Props
McCauley & Sensenich have no approved procedure for polishing. Part of the overhaul manual for these propellers lists the required preservative coatings and paints. By polishing the propeller you've removed those coatings and, technically, the propeller does not meet its manufacturer's instructions for continued airworthiness. I encourage anyone who doubts the above contact the propeller manufacturers directly to get their questions answered. Or, contact your local FSDO.

The prop decals that Moodys and Chief sell are not the correct decals for McCauley props made in the 40's and 50's. I have the correct ones available for $22.00 a pair.

I too have heard that polishing is a no-no. But I still don't know the correct paint colors... Anyone?

A semi-gloss gray with red tips.

gparker wrote:I too have heard that polishing is a no-no. But I still don't know the correct paint colors... Anyone?

I don't know if using the term "correct" ...is, er, uhm... correct....or not...but.... McCauley has changed their Instructions for Continued Airworthiness over the years. Back in the days...(prior to 1970s) they painted their props with a grey "Polane" paint, with safety tips in either yellow, red, or white (according to the wishes of the consumer, or barring such instructions, white.)

After 1980 McCauley began using a flat black which has become quite standard since it's easy to touch up. The tips are usually white.

My own is (or was at one time) polished. The rumors that some FAA inspectors were obtuse about that became a humorous anecdote when it was pointed out that polishing is not only a form of "cleaning" for inspection, but is also how FAA's own DC-3 props were kept.

Paint is a protective method to delay corrosion. Polishing keeps the corrosion removed. Paint is not mandatory, IMO (worth what you paid for it.) If you worry about this sort of thing, then perhaps you might consider clearcoating your prop and signing it off as a minor alteration.

I don't have a close-up of the prop handy, but this is they way they were in 1950. Satin anodized aluminum with red tips and flat black on the back. Don't know if my decals are correct - just what Wag-Aero sells.