P51 Mustang wings, painted or not ?

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Member for

11 years 2 months

Posts: 2,536

Been reading a model mag which has an article regarding the Red Tailed P51's in WW2.
It states that Red Tail P51's had their wings painted (grey) to prevent corrosion due to them being made of a different alloy to the fuselage.

So was the painting of P51 wings a standard thing in WW2 or was it just some squadrons, marks of aircraft, theaters that did it?
I'm talking about bare metal aircraft.

Thanks.

Original post

Member for

10 years 3 months

Posts: 57

Bare metal P-51s actually had a lacquer applied to the wings to prevent corrosion and also to fill any imperfections in the surface - it was intended to have the surface of the wings as smooth as possible to maximise the efficiency of the laminar flow section - in practive the wings tended to get grubby anyway - hardly surprising.
Mike

Member for

12 years

Posts: 957

All P-51 wings were painted with a silver/aluminium paint (probably a cellulose lacquer as said, they were common) after being filled and smoothed to guarantee a smooth external finish, as said above. In practice this proved difficult to maintain in service so it was removed, with (supposedly) no loss in performance. Given that it would have been in a poor state before being stripped, that might even be true, as long as the leading edges were kept in good condition. The story about the Red-tails is surely a myth: I've not seen any other comment about them repainting the wings and there's nothing in the corrosion reason given.

Member for

14 years 11 months

Posts: 704

http://i116.photobucket.com/albums/o31/alachetta/IMG_zps6jecly0m.jpg

The first 40% of the wing cord was first painted with one coat of zinc chromate primer followed by enough coats of Acme Gray Surfacer No. 53N5 to cover all irregularities. Skin butt joints were filled with Acme Red Vellunite glazing putty No. 58485. The entire area was then sanded down and sprayed with one coat of camouflage enamel. When camouflage was deleted the forward portion of the wing, sometimes the entire wing, was painted aluminium.

On the 1st January 1944 NAA issued a factory order for the deletion of camouflage of future bomber and fighter production.

“At the earliest date without delaying production, camouflage paint will be deleted from all spares delivered concurrently with aeroplanes without camouflage. Exterior surfaces such as fabric, plywood, magnesium, and dural with require protective primers of aluminized coloring. Alclad or stainless steel require no covering. Antiglare paint will be on top of fuselage covering forward vision areas to aid pilot. The propellers will remain black with yellow tips.”

“The wing leading edge of the Mustang will be smoothed and surfaced as outlined in the P-51 B and P-51C Series Repair Manual Report No NA5741, with exception that the camouflage coats will be deleted and aluminized lacquer will be applied over the surfaces. The deletion of the camouflage will eliminate approximately 42 pounds of finish from the B-25 series Airplanes and 16 pounds of finish from the P-51 Series Airplanes. It is anticipated that the removal of the camouflage will also result in materially increased speed.”

At the factory a special type of thinner that did not attack the grey smoother was used to remove the camouflage. In the field the thinners available would damage and remove the smoother. Rivet heads, rough edges etc., were exposed and created unwanted drag. To prevent this NAA recommended USAAF bases to use the following procedure.

“In place of removing the camouflage from the airfoil smoother, apply addition paint to the area, which extends from the wing leading edge to approximately 40 percent chord. Use a mixture containing 8 ounces aluminum paste to each unthinned gallon of clear lacquer (Spec. AN-TT-L-51) or clear vanish (Spec. AN-TT-V-188). This will allow the surface to assume the necessary appearance of unpainted aluminum or stainless steel. Any specified thinner may be used for the removal of camouflage from all other surfaces of the aircraft.”

Member for

10 years 6 months

Posts: 409

That is an excellent post by Antoni. The earlier mentioning of the silver paint on the wings being there for corrosion prevention is completely false. The only reason the wings were painted silver by NAA (on the bare metal Mustangs) was to cover over the primer and filler applied to the wings so as to match the finish of the bare metal. Had NAA not gone to the efforts they did to apply the "aerodynamic smoothing compound", as they referred to it, they wouldn't have bothered to paint the wings. There was no need to paint/primer the aluminum, as it was all Alclad (wings/fuselage/tail).

Here are some photos of the filling/sanding process at work on the wings for the restored P-51D-20-NA "Sierra Sue II" (the most authentic/accurate restored P-51). The work seen here was done to match photos and specifications for the time period that the P-51D-20-NA series was being manufactured. The gear doors, fuel tank doors, flaps and ailerons were all left bare metal.

(First three photos by Aircorps Aviation)

http://i7.photobucket.com/albums/y282/Bomber_12th/Bomber_12th001/10462969_781627101878211_38715681895695959_n_zpsic7faams.jpg

http://i7.photobucket.com/albums/y282/Bomber_12th/Bomber_12th001/10417508_781627055211549_4378469405452276117_n_zpsk3ipkymq.jpg

http://i7.photobucket.com/albums/y282/Bomber_12th/Bomber_12th001/2014-06-0110JJ_zpsgd4lsbnt.jpg

(Photo by Max Haynes)

http://i7.photobucket.com/albums/y282/Bomber_12th/Bomber_12th001/10733855_871016166272637_1517350759715589746_o_zpshxs7mdmm.jpg

Member for

11 years 2 months

Posts: 2,536

Thanks for the replies.
So the `grey` would appear to be laquer giving the wing an appearance of grey as in the above photo.
:-)