Old Technology - Blue Touchpaper

Discussion in 'Fireworks Nostalgia, Collectables And History' started by spectrum, Aug 30, 2014.

  1. Tinderbox

    Tinderbox Pro Firer/Crew

    That looks like good stuff. Is this your own Malta Pyro?
  2. malta pyro

    malta pyro Supports UKFR

    Yes that’s my own, mist sprayed both sides and left to dry, I made it a few years back for a company I will dig out the paper I used sure I still have it.

    Oh am i in the club guys?
    jww likes this.
  3. jww


    Thank you for that fascinating contribution Tinderbox - there was a lot of information in there re: paper type, behaviour of paper in flat / rolled., rate of burning, the "tracking" effect we're learning about. I'm sure that BTP of childhood - as I've previously noted - could take forever to set the item off - that feeble glow in the distance was part of the anticipation. I do have some little pieces of original factory BTP around, so one of those would be a useful reference. Finding time a strain currently, but will get there ! BTW., love the inclusion of the inquisitive swan in the video - some subtle reference to Swan matches no doubt :) Again, thanks - very very helpful. J.
    Tinderbox likes this.
  4. Tinderbox

    Tinderbox Pro Firer/Crew

    Mist spraying looks like a pretty good method then. What paper did you use?
    Consider yourself a fully fledged member!
    jww likes this.
  5. Tinderbox

    Tinderbox Pro Firer/Crew

    We have a family of swans who wont leave us alone. the girlfriend insists on feeding them and now they have learned to tap on the windows and stamp their feet under water so the who boat sounds like we're sinking. Quite cute until they wake you up at 4am!
    jww likes this.
  6. jww


    Great note - thank you - brought a smile and I can see the logo of a Swan tugging on a bit of BTP to be a possible way forward :) J.
  7. jww


    So that was "left to dry" as opposed to forced drying which is really interesting. I think we're building up a really good little empirical knowledge base here - love the way the various folks are bringing their experiments and results to the table ( funnily enough, this is the way modern pharma. has gone for some of its collaborative research...) J.
  8. malta pyro

    malta pyro Supports UKFR

    The paper is MG (Machine Glazed) 20 GSM Royal blue acid free, mist spraying is the best way to go as you don’t tend to disrupt the fibre’s too much, looking through my store I found around 800 grams of the un treated paper.
  9. malta pyro

    malta pyro Supports UKFR

    Force drying is not advised until the nitrate has fully entangled the cellulose fibres in the paper, you need to let it dry for at least 6hrs at ambient temperature you can then use a little heat should you wish, if you see nitrate crystals on the paper you got it wrong.
    jww likes this.
  10. Tinderbox

    Tinderbox Pro Firer/Crew

    Spectrum mentions that Standard had a machine which used sets of rollers. One set squeezed out nitrate solution after the paper ran under a bath of the stuff. The other set of rollers were heated and dried the paper. Sure I linked it somewhere.
  11. Tinderbox

    Tinderbox Pro Firer/Crew

    Ah, so this is the tissue paper you were talking about. First Google search and the top listing is:


    Burns nicely. I'm after something a bit sturdier than tissue paper so I'll try the newsprint when it arrives. Starting to get pretty good this topic.
    Last edited: Mar 11, 2018
  12. malta pyro

    malta pyro Supports UKFR

    Not at that price! But it is about right.
  13. ok, so I found some blue touch paper, 7cm x 7cm, >10 years old,
    not stored optimally.
    here is a comparison of old vs freshly prepared sample.
    the blue dye used was some left over from making iron gall ink, and so is not a perfect match for colour.
    from plain 43 gsm newsprint to blue touch paper took ~< 5mins
    the fresh stuff burned quite reliably when rolled up
    obviously not a commercial process but useful for the odd sample.

    http://www.pyrobin.com/files/BLUE TOUCH PAPER.wmv
  14. Tinderbox

    Tinderbox Pro Firer/Crew

    Brilliant work Dave. So, is the stuff in your hand LEFT - old and RIGHT - newly made by you?

    What was the strength of your KNO3 solution? (Grams per pint/litre etc)

    The hot plate method worked well. Nice contribution!

    As a side interest, my mate Terry is a living historian/historical interperator and he makes iron gall ink using oak galls, gum arabic and some other bits including beer. It's to one of Isaak Newton's recipes. Does workshops with kids making it. What do you use/make it for?
  15. yes
    left hand =old
    right hand=fresh(new)
    20% wt/vol solution with 1% dye added

    re the ink, i used the pure chemicals (iron sulphate, tannic acid, gallic acid, blue dye, hydrochloric acid )
    to be honest its far easier to buy it, and if interested the best on the market is the brand KWZ Blue-Black (from Poland)
    available in the uk from hamiliton pens ltd
    Tinderbox likes this.
  16. Tinderbox

    Tinderbox Pro Firer/Crew

    What do you use the ink for then? Must be something special if you are making it up from raw ingredients...except BTP of course.
  17. i just like to use permanent ink:)
    .......not mention german nano ink.....;)
  18. Tinderbox

    Tinderbox Pro Firer/Crew

  19. no way !!!!
    purely for writing and having a permanent record
  20. I have had a look at what three prominent 19th century British writers of books for amateur pyrotechnists had to say about touchpaper.

    The four books I consulted are:

    Thomas Kentish, 'The Pyrotechnist's Treasury', London: Chatto & Windus (1878), pages 23-24
    'Practicus' (Denis TImes Moore), 'A Manual of Pyrotechny', London: Bolton & Co and Wolverhampton: Wm. Bailey & Son (1872), pages 66 and 5.
    Anonymous (but authoritatively attributed to 'Practicus'), 'Pyrotechny or the Art of Making Fireworks', London: Ward Lock and Tyler (no date; ca. 1871), page 71.
    WIlliam Henry Browne 'Firework Making for Amateurs', London: L. Upcott Gill (no date; ca. 1888), pages 72-73.

    In summary:

    All three authors agree that the potassium nitrate should be dissolved in water ( no vinegar, 'spirits of wine', etc.).

    Kentish and 'Practicus' recommend the same concentration, which in modern units is very close to 50 grams per litre; Browne recommends a somewhat more dilute solution (~37 grams per litre). Practicus warns that if the solution is made too strong, the nitrate will 'recrystallise as the water evaporates in drying, and this should not be the case'.

    All recommend that the potassium nitrate solution be applied to one side only of the paper, with a paintbrush or sponge.

    Kentish and Browne tell us that the paper should be hung on a line to dry; 'Practicus' does not suggest how to dry it.

    Kentish and Practicus say that blue paper should be used, while Browne says the paper can be white or blue.

    All say that the paper should be 'Double crown' - but as noted eleshwer in this discussion, 'Double Crown' is the sheet size and is not sufficient specification. Browne does not mention the weight, but Kentish says it should be '12 lb' and 'Practicus' says that 'from 11 lbs to 13 lbs per ream' , with 11 lbs being the most generally useful. 'Practicus' is firm that weights above 13 lbs per ream 'must not be used'.

    In modern units 11 lbs per ream corresponds to about 26 gsm. I say 'about' because there is some uncertainty as to whether a ream was 500, 516 or 480 sheets. If 500 is right, then the exact conversion is 25.8 gsm Our modern 30 gsm paper would be roughly the same as the 13 lbs stated by 'Practicus' as being the upper limit of usefulness. 'Practicus' described the suitable blue paper as 'not as thin as tissue paper, but thicker than the ordinary blue paper used by shopkeepers.' This blue paper was evidently readily available in the 1870s. I have some thin dark blue paper that seems to meet 'Practicus' description. It was being used as packing paper, and I kept it for its resemblance to blue touch papero, but I have not seen it for sale.

    'Practicus' gives the price of 'Dark Blue Double Crown', 11 lb, as 8 shillings and sixpence per ream of 20 inch by 30 inch sheets. A ream was typically 500 sheets. For comparison, he gives the price of saltpetre as 6d to 8d per pound. If we take the average and say that saltpeter cost 7d per pound, then a pound of saltpeter would have cost the same as about 13 square metres of the recommended blue paper.

    I hope some of this will be of interest...
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