[Eric Larger]

Hello

first do not forget that these documents are attached to tests done in summer 1944.

Effectively if putty is used to smooth the under surface , it has also a function of protection . This putty was probably useed to seam the panel lines and to avoid anything (mud, oil, dirt...) to come into the space left between two aluminium panels. I think that first they tried to test if undersurfaces puttied can resist to airflow . This , in anyway, save material as no paint was applied over . And it saved a lot of time .

Now the reality and the use at a large production scale is different . Please look carefully to several pictures of Fw 190D-9 , this is the example I know the best , and look carefully at the state of the surfaces (fuselage , wings , tail) , you can notice that on any of these surfaces , no putty was applied to seam panel lines or to cover rivets . So the request in the test of using putty was abandonned .

At that time , as I said previously , there was no need to do it , due to the very short lifetime of an aircraft . The term of performances should not be taken in account , the purpose was to produce as fast as possible war machines .

Now concidering the used of light paint on upper surfaces . We think that the undersurfaces paint (RLm76, Green-blue, or RLM75 ) was also applied on uppersurfaces , on some pruction batches .This paint could also act as a primer on upper surfaces ( the most important surface to hide the aircraft from the air ) and then a full or partial camouflage scheme (RLM82 , 81 , 83 or rlm75 ) was applied producing examples well identified like RLM 76/83(W.nr 211939) , or RLM 75/83 (210051), or RLM82/83 (210102).

The some paint can be applied at unit level to cover repairs , the best example is W.Nr 211934 ( initial painting scheme W2 undersurfaces (metal + rlm76), RLM83/82 uppersurfaces .One wing has repainted undersurfaces (starboard wing ) with rlm76 (balkenkreuz area) and uppersurfaces (same wing) with RLM75 see pages 160 to 164.

This is just guess as no document so far (known to me ) has been found to confirm this .

On the other hand RLm 76 or RLm75 can be used on the undersurfaces to mask some minor repairs see page 40 (photo in the middle) of our book it is clearly visible .

We do not think that RLm77 was used but more probably a new variant of RLM76 called 'Weissblau" , containing less cobalt blue pigments .

hope that helps

Eric Larger