I would love to see the whole memo. I also suspect King's numbers are in error. 8 oz. equals one cup. Add one cup of black paint to a gallon of gray, you've not darkened it very much. (As your results show...) He might have read something, then garbled it in his head, and mis-quoted it here (and likely whoever typed this up had no idea themselves, and anyone who did wasn't going to correct the Admiral.)
There was an official published formula to convert #5 Gray to 5D. A special black paste...5-BP...was developed, and distributed, and intended to be used to make 5D from the remaining stocks of #5 Gray. The specifications called for the 5-BP paste to be packaged in such a way that each package would convert 5 gallons of #5 Gray. That came out to 1.25 pounds of 5-BP to every 5 gallons of #5 Gray.
The paste...being labeled a paste...should have been denser than any paint. So, 1.25 pounds of the stuff should have been equal to more tinting material than would have been in a black paint. So, dumping a cup of black paint into a gallon of the gray, and expecting it to turn as dark as desired shows something is plainly wrong somewhere. King clearly meant well...use black paint if you can't get the paste, and use up the #5 Gray. But, these instructions on how to go about that--based on what you show here--are clearly wrong.
King supposedly had quite a temper. Who is going to tell the good Admiral his memo is "nonsense"? This looks like a case of "Yes, sir! Thank you, Sir!" then quietly go do it correctly.
Good question. Iím not sure. Iíve questioned the accuracy of some of their colors, namely their 5-L paint but I thought their Standard Navy Gray #5 was a close match to the actual color.
Iím starting to think Admiral King got his numbers all wrong.
Numbers look right - approx. 16 to 1 would seem to match but... Are the source colors right?
March 22, 1941 Admiral King authorized adding black striping paint to Standard Navy Gray to produce another version of 5-D until the proper mixture was available to the Atlantic fleet.
USS Yorktown is known to have utilized this version of 5-D when she arrived in Bermuda in May 1941.
I decided to try this conversion using White Ensigns Colourcoats. I used their SNG #5 and their Black for the conversion. Also shown is their 5-D for comparison.
Not at all the result I was expecting to see! Did I get my conversion wrong with adding .875ml of Black to 14ml SNG #5? Math is NOT my strong point!
Here are the results.