Vapalux 300 colour

Discussion in 'Pressure Lamp Discussion Forum' started by KenC, Sep 7, 2025.

  1. KenC United Kingdom

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    I’ve acquired a 1943 Vapalux 300 in very poor condition that has unfortunately been overpainted in its life. I’ve been looking into paint colours in case I decide to restore rather than fettle. I’ve read all the various mentions of “Rapidal grey”, which was first mentioned (I believe) in Ian Ashton’s book. Does anyone know what Rapidal is? I’ve searched endlessly online and find no mention of it being a colour. As far as I can work out, the government specified BS381c paint colours for equipment suppliers. There’s no such colour. So, here’s my thought: does Rapidal instead refer to the type of paint? During the war there was a big increase in Alkyd enamel paint production because of its advantages (quick drying, chemical tolerance, durability). So I wonder whether Rapidal stood for rapid alkyd.

    I also read that, although there were standards, paint colours probably changed a lot depending on supply of materials. I’ll do my best to match what’s under the top coat, but that’s very difficult. Any ideas welcome.
     
  2. podbros

    podbros United Kingdom Subscriber

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    Hi Ken

    i had a quick search and found this from Gary .. when you find it, scroll down and he shows a thumbnail with the paint he used

    IMG_5700.jpeg

    good hunting :thumbup:
     
  3. Fireexit1 United Kingdom

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  4. KenC United Kingdom

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    Hi Chris, indeed BS381c has a large range of colours, and I understand they changed during and since the war, with new camouflage colours coming in for example. The one I’ve seen mentioned elsewhere on the forum is 633 RAF grey/blue. I’ve got some dark sea grey and it was surprisingly much too light. Maybe this is a fool’s errand, but I’d still be interested to know if rapidal grey was actually a thing. We’d need someone like Ian Ashton who has the logs of the manufacturer Griffiths Brothers.
     
  5. Fireexit1 United Kingdom

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    So Graces guide has an entry for Griffiths Brothers : Griffiths Brothers and Co - Graces Guide
    but not much there.

    A trademark search on "rapidal" reveals another company - Crosbie Coatings Limited of wolverhampton had regisered that name in 1908, in the category of Paints, enamels and varnishes.
    https://trademarks.ipo.gov.uk/ipo-tmcase/page/Results/1/UK00000302398
    by 1937 it had become Adolphe Crosbie and Co.

    Interestingly Adolphe Crosbie incorporated a company called Crosbie Coatings Limited in the 50's which only went into liquidation in 2018. And they went as far as to renew the trademark.
     
  6. Gary Waller

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  7. Fireexit1 United Kingdom

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    Bialaddin 300x Repainted was my effort. Not quite the right colour but it was cheap and easy ! (and has lasted well)
     
  8. MYN

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    Ian Aston did mentioned it was an RAF Blue-Grey colour in his book.
    Accordingly, it was supplied to Willis & Bates and the military for the early 40s Vapalux by Griffiths Brothers and Co.,Ltd, Macks Road, Bermondsey, London.
    The web search for 'Rapidal Grey' hasn't produce much conclusive info. Pretty tall order for something that obscured.
    From the following record of 'Post Office London', I believe Rapidal, Aquol and Ferrodor were trademarks for the paints by Griffiths Bros & Co. Ltd. of Bermondsey:
    Screenshot_20250909_162258_Adobe Acrobat.jpg

    No info on Rapidal's paint binder/base.
    Aquol was something like a water washable paint.
    Ferrodor was a micaceous iron oxide alkyd-based paints for railways and steel structures. Up til the 40s Linseed oil was boiled with Litharge for the binder in micaceous iron oxide paints. Copal was used to improve drying properties. Copal resin was imported from the tropics.
    Rapid-Alkyd does make some sense. Rapidal: the 'al' can be anyone's guess,...alkyd, aluminium, perhaps even Copal?
    There weren't that many oil-based paints in the 1940s. Alkyd-based paints(perhaps with certain fillers, dryers, white lead and aluminium powder extenders, etc) had already been developed to become fast or rapid drying by that time.
    Nitrocellulose- and phathalate-based lacquers/enamels were also common.(use on WWII military aircrafts known).
    Acrylic(both oil and water based) paints weren't commonly available until at least, the 1950s. Epoxy and polyurethane paints, certainly not there yet.

    Unless if Ian Ashton have the relevant records on the manufacturer's product and can be contacted, finding details on the elusive Rapidal Grey might be a tad bit difficult.
    The exact composition of the old paint can only be revealed using some elaborate, forensic-styled analytical means like the one done in the pdf attachment below.
    I think your best option would be to find someone with a 'new-old stock' 1941-1943 period Vapalux and a professional custom paint colour blending shop machine to help out on matching.
     

    Attached Files:

  9. KenC United Kingdom

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    Thanks @MYN, I hadn’t thought to look up patents. So that proves me wrong because alkyd paints weren’t developed until the 1920s. But it answers my question whether Rapidal referred to the colour or the paint type - it sounds like it was RAF blue/grey “rapidal paint”. If this colour is the same as BS381c 633 then it still exists and seems a good fit. I’ll give it a go and report back. I may be some time…
     
  10. MYN

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    I'm not sure if the specific BS381C 633(RAF Blue-Grey) code was even introduced during the early 1940s. No idea how this shade of grey was named as such. It might not be the exact colour which the RAF actually used on their aircrafts or other equipment during that time.

    I'm only wondering what was the exact "RAF Blue/Grey" colour reference mentioned by Ian Ashton when referring to what was known as Rapidal Grey. The RAF Blue-Grey name might not be anything historically related to that period when the first Vapaluxes were made. It could be just a colour which Ian had found to be coincidentally matching to the original Rapidal Grey.
    Historically, there had been a number of greys used by the RAF including the Medium Sea Grey, Ocean Grey and Basic Grey around that period.
    The blue-grey colour had also been used on RAF uniforms (perhaps with some variations in shades over the course of time since adopting it).
     
  11. KenC United Kingdom

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    I found this nice summary on AI. It seems to have mainly come from extensive discussions on military enthusiast forums.

    upload_2025-9-10_8-39-26.jpeg
    “BS 381 was the British Standards Institution's first color standard, published in 1930, and consisted of individual colors for military, government, and industrial use in camouflage, identification, and coding. It was a crucial standard during World War II and was later developed into BS 381C, a broader standard for ready-mixed paints.”

    So RAF grey/blue existed. Just a question of whether it was used by Vapalux. The government will probably have insisted on a standard rather than allowing Vapalux to choose. I’ll be able to cross reference with the remaining (overcoated) original paint. But again, apparently colours varied because of supply issues.
     
  12. KenC United Kingdom

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    RAF blue-grey BS.33

    “Originally, RAF Blue Grey was BS 381 No.33. When BS 381C was issued in 1948, the numbering was changed to a three figure system in which the first digit denoted the group of colours to which each individual colour belonged. '6' denotes a grey, '33' denotes the particular shade of grey. Thus BS 381 No.33 RAF Blue Grey became BS 381C (1948) No.633 RAF Blue Grey.”
     
  13. MYN

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    In the end, I would suppose finding the exact historical or product details on the original "Rapidal Grey" might prove to be a lot more difficult than actually getting a modern paint with the exact colour match for the 1943 Vapalux 300 :lol:.
     
  14. MYN

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    By the way, just for interest, here's the link to the March 1983 issue of the Journal of the Oil and Colour Chemists' Association.
    Within, there was a mention of the "Ferrodor" Micaceous Iron Oxide paints by the same manufacturer of the "Rapidal" products: Griffiths Brothers and Co., Ltd, Macks Road, Bermondsey, S.E.16, London.

    https://www.google.com/url?sa=t&sou...zsoNegQIBRAL&usg=AOvVaw3DLM-mxmotYkXSt1ZwXq6D
     

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