PB10 Paint for late WWII Royal Navy Submarines
I've been working for a while now to create an accurate (well, very, very close to accurate) PB10 model paint for Royal Navy late WWII submarines such as the Improved S class and T class boats. This has been a real challenge for me as the real PB10 was made exclusively from white and ultramarine blue pigments resulting in a vibrant blue with ultramarine's particular red-leaning caste very difficult to create with anything other than those two pigments, yet ultramarine as a pigment has some long term stability issues and as such it's not generally available as an opacity-assured commercial colourant suitable for use in repeatable model paint manufacture.
It's taken a ridiculous amount of time, and so many iterative corrections that my first batch was over-dosed with pigment by almost 200% forcing me to turn it into a bigger batch just to get the maximum pigment content back within the upper limit for the paint binder I use. It's not absolutely bang on the dot, but it's very close and much closer to real PB10 than anything else on the market claiming to be PB10. I'm quite happy with this.
On 12th October 1944, the Admiralty promulgated Confidential Admiralty Fleet Order 2269/44 which introduced the standard camouflage designs familiar to many. Section 6 entitled “Scheme H” provided the first standardised scheme for RN submarines, and introduced the new colour PB10.
Sub-paragraph (c) listed the formula for obtaining colour PB10 as follows:
AP409 white lead oil paste - 51lbs
AP104 zinc oxide oil paste - 20lbs
Linseed oil, extra pale, boiled - 6 pints
AP773 liquid driers - 3 pints
White spirit - 7 pints
Whilst a sample of PB10 has been offered by Snyder & Short in the past and copied by our competitors, it is not possible to arrive at such a shade using only white and ultramarine pigments as specified in the original documentation. The appearance of this sample may potentially be attributed to age-browning of the binder of any original linseed oil paint. We at Sovereign Hobbies reproduced a series of fresh samples with the specified original ingredients and using our modern equipment were able to iterate the proportions slightly to arrive at the specified 10% RF for this colour, with the resultant but distinctive shade being corroborated against contemporary artwork and surviving contemporary models. The challenge has been replicating this very distinctive shade using modern commercial paint tints, but we believe we have achieved a viable model paint shade very close to our target made using the ultramarine pigment. Our new PB10 is, once again, the best Royal Navy model paint on the market.