Half painted Fw 190 wing undersides - the purpose?

[Crumpp]

15-20 lb on fighters

I think something got confused here. They have to be talking about per coat of paint on a small fighter.

Either that or our paint guy was refering too the total weight of the paint before he put it on the aircraft. I will find out.

Comparison test had shown a gain of between 4 and 7 mph, with weight saving dependent on the aircraft size and model"..

Good stuff. So bare metal was the better of the finishes for US Aircraft. This would not be the first time US results were different from British results in aircraft testing.

Naval aircraft continued their finishes,

Certainly. The ocean is the harshest enviroment on earth especially for metals. Corrosion protection is probably on a different priority level in comparision to land base aircraft. Painting and scraping is a career in the Navy.

http://www.gim.bnl.gov/misc/envtest/...corrosion.html

Atmospheric corrosion is primarily due to moisture and oxygen but is accentuated by contaminants such as sulphur compounds and sodium chloride (salt spray) Corrosion of steel on a sea coast is 400 to 500 times greatrer than it is in a desert. Steel specimens 80 feet from a coast corroded 12 times faster than those 800 feet away. Salt is the chief contaminant.

I imagine life on a Carrier Deck is very tough on metal airframes.

All the best,

Crumpp

[Crumpp]

I think something got confused here.

15-20 lb on fighters

I remembered to talk to Gary about this issue. I was confused. The paintjob added roughly 800lbs including interior finish to a B17. However on a P51 it only takes 4 gallons to completely paint the airplane.

Both the RLM and the USAAF used cellulose-nitrate based lacquers and the USAAF used Zinc Chromate Primer which is extremely heavy. The finish is thick and chips easily increasing drag.

While the milling of the German paints was much finer, it was their chemical engineering of the fillers that allowed the thinner, lighter, and equally smooth finish, combined with the fact they did not use a heavy metal based primer.

All the best,

Gene