Luftwaffe floatplane float underside colour - yellow?

[richdlc]

Hi guys

working away on the He 115 book.... however a problem has arisen. The text seems to suggest that some He 115s had the undersides of the floats painted yellow.
My question is - is there any evidence whatsoever that ANY Luftwaffe floatplanes had yellow-painted float undersides? I'm working with Nigel Moore on this so he might want to chip in.

I've sold the books of Ullmann and Merrick (in all versions and updates/editions) many times, but am not intimately familiar with them. What do they say?

Any other books shed any light? (les hydravions de la luftwaffe?)

Any original documents (any comment Nigel?)

I'm not going to suggest anyone is wrong or right at this point, but would like to open a discussion.
Thanks
Rich

[flyvrak]

https://flyvrak.info/storsalen.html

[edwest2]

Yes, in Swedish service.


https://photos.kitmaker.net/review/1...painting_1.jpg

[INM@RLM]

Some flesh on the bones that Rich has set out:


1. In the 1938 version of L.Dv. 521/1, regarding painting of the above and below water portions of maritime aircraft, there were actually two options mandated for Flieglackette 02 (farbig) [Only paints (lacquers) from Lacquer Group 02 (Flieglackkette Nr. 02) could be applied to surfaces that were immersed in water, so only paints from this group could be applied to the upper- and undersides of flying boat hulls and floats]:
Option 1
First an undercoat of Ikarol-Decklack 111 = commercial designation of the sole manufacturer, Warnecke und Böhm, now designated by the RLM as Flieglack 7106._ (i.e. of no particular colour)
For the Unterwasserteil Ikarol-Decklack Grau 103/1 = commercial designation of the sole manufacturer, Warnecke und Böhm, now designated by the RLM as Flieglack 7108.02
For the Überwasserteil Ikarol-Decklack 103/2 = commercial designation of the sole manufacturer, Warnecke und Böhm, now designated by the RLM as Flieglack 7107.02
The .02 indicating the RLM grau colour tone.

Option 2
Paints applied in two coats with the same paints being used for both above and below water parts
For the undercoat Ikarol-Decklack Gelb = commercial designation of the sole manufacturer, Warnecke und Böhm, now designated by the RLM as Flieglack 7106.27
For the top coat Ikarol-Decklack 111 = commercial designation of the sole manufacturer, Warnecke und Böhm, now designated by the RLM as Flieglack 7108.04
The .04 indicating the RLM yellow colour tone, and the .27 the RLM yellow colour tone (generally reserved for markings).

Curiously, it is only the application of this second option that is explicitly described in a later section of this instruction:
"A fuselage designed as a floating hull will be painted with aviation lacquer group 02 on all metals, namely lacquer 7108.02 as the topcoat for the entire underwater section to 10 cm above the highest water line, lacquer 7107.02 externally above the water line and lacquer 7108.01 or 02 internally. ...
"Floats: aviation lacquer group 02 on all metals, 7106.27 being used as an undercoat, 7108.04 as finish."


2. However, the 1939 edition of Der Flugzeug-Maler (issued a year or more after the March 1938 issue of the L.Dv. 521/1 instruction) only lists as Group 02 paints Fliegerlack 7108.01 (Silber for underwater) and 7107.02 (RLM grau for above water). No mention of any 04 Gelb/yellow or 27 Gelb/yellow at all in Flieglakette Nr. 02.


On the face of it then neither of the two new options set out in the 1938 L.Dv. 521/1 for the painting of floats actually came into effect.


There may have been good reasons for that. The protective element in the Flieglack 7108 lacquers used for the underwater areas was aluminium bronze, which is an alloy of copper with about 6% of nickel and iron, and 9 to 12% of aluminium, and copper was something that there was never enough of in arming Germany.
Just one example of that: Homze: Arming the Luftwaffe p.228 notes that in the quota allocations of raw materials made June 1939 by the Office of the Four-Year Plan, the Luftwaffe received just 37.5% of its requested copper allocation calculated as necessary to meet aircraft delivery plan 11 (Lieferplan 11) of April 1939 (running through to end March 1942).

[INM@RLM]

RE: Post 2 The photo at top right is certainly interesting and potentially useful. It's a bit short on description though.

To my eyes it looks like part of the inside of the float not the outside. The inside areas of floats in L.Dv. 521/1 were mandated to be painted with either RLM 7108.01 Silber or 7108.02 RLM grau. i.e. never with Flieglack 7108.04.

I should have also added that aluminium bronze has a gold colour. So it would not be too surprising if the longest lasting gold-coloured part of the pigment was the component that survived the longest on this wreckage.

Not clear also from this photo is whether we are looking at part of the upper section of the float or this is definitely a portion from the concave curved areas that would be submerged when the aircraft was at rest on the water. On the face of it this panel looks too flat to have come from the underwater section, suggesting that more likely it was actually part of the internal structure of the float that would never have received any yellow paint.
This query is only about the paint applied to the submerged EXTERNAL areas of the floats.

[INM@RLM]

RE: Post 3 Thank you, Ed. Not directly germane but it does make me curious now about where the Swedish AF bought the paints for their He 115s and 114s finished in such a scheme. The answer to that I think has to be lie in Swedish records. (We seem to have books about every other nation's camouflage colours, just nothing detailed for WW2 Sweden AFAIK.)

That also rather leads to the next question, could/did the Swedes supply EHF with the paint that was used for the delivery scheme of their new He 115s? Again what do Swedish records indicate?
In other words - just to float the question only at this point - could the yellow colour used for the float bottoms on Swedish floatplanes have been a direct function of a paint with an even higher proportion of aluminium bronze pigment, hence an even stronger goldish tone?

[INM@RLM]

I'm going back to post #2.

The more I look at this photo the less I see 'float', and the more I see 'wing cross section'. As in, this is the outside of the divider behind which lay the fuel tank in the port outer wing. So more likely in my judgement this shot shows the inboard section of the outer port wing that would have been attached just outboard of the engine nacelle.

Per the 1938 L.Dv. 521/1, for "Painting of exterior metal parts of land and naval aircraft and interior parts of naval aircraft' Lacquer Group 01 applied and the mandated colour for the more modern designs was Flieglack 7107.02 i.e. RLM grau.
(Again no mention of any .04 or .27 yellow tones in this connection. But then why would you use the then equivalent of a hi-vis paint on the internal surfaces of a maritime aircraft?)


Someone will know more, I'm sure.

[INM@RLM]

Picking up from post #2 & #6, I thought to turn over my copy of Mikael Forslund's 'Heinkelflüg i Sverige' and on the outside back cover there is a very nice colour shot in a good size of a Swedish He 115 taken from head-on.

The concave portions of the front of each float's undersides are in shadow but the prow of each float is in sunlight. The float undersides are clearly not yellow, nor are they the dark green shown in the Aeroscale drawing at https://photos.kitmaker.net/review/1...painting_1.jpg.
They look a tad light for RLM grau, but a dull matte silver finish would be a credible interpretation - to my eyes at least.
Perhaps other colour shots survive from the same session?

[Stig Jarlevik]

All Swedish sources I have available regarding the painting of the underside of the floats state they were
painted yellow upon delivery from Heinkel.

This yellow painting was discarded at some time during the autumn 1941 and spring 1942.

Unfortunately it is not stated which colour that replaced the yellow, but since it was much lighter, my guess
is some kind of grey. Matt Silver? Possible I suppose.....

Since I am not a model builder, my interest in colours are not very high....

Cheers
Stig

[INM@RLM]

Very many thanks for your checks, Stig.
This is an evidence collecting expedition. (My 'role' is only to set out the framework for a discussion.) I know Rich will greatly appreciate whatever parts of this evidence you are willing to share with him.