Primus "Ultraprimus Type" Late 1890s

Discussion in 'Other Models' started by Sedgman, Sep 25, 2020.

  1. Sedgman

    Sedgman Subscriber

    Dec 1, 2014
    Alight - Copy.jpg


    These types of stoves, with upright burner(s) and no pan support legs, are often used for operating a furnace to melt metal or heat things like soldering irons. They are often known as rocket stoves. This stove is one of a family of stoves that can have one or more burners. From what I have been able to discern, I believe my stove to be an early, but not earliest, Primus ‘Ultraprimus’ variant, possibly a Model 1 or 2A owing to the fount capacity.

    Dating the Stove

    This stove is quite old, being in the group of stoves Primus made prior to 1911, which is when stamping founts with a date code commenced. This stove has the very early ‘Duelling Blowlamps’ logo stamped into the fount (1896 onwards) and has the AKT.BOL. stamping on the filler cap (1898+) and a circular stamp on the base (1897+). The air screw is unmarked which apparently indicates an earlier model too. I note and acknowledge that @igh371 has contributed a lot of good information in a number of posts or replies.

    Logo on Fount Side - Copy.jpg

    Relevant Posts

    Some selected relevant information on similar stoves/furnaces can be found in the Stove Reference Gallery and in the Primus area as follows:

    • One very similar to mine, was posted by @presscall in the section Other Models. Here.
    • Another excellent post, here, was by @igh371 in the section Primus Early Models (un-numbered).
    • A post enquiring about the logo by @Tony Press has further information about dating these old stoves. Click here.
    • Ultraprimus No 2 by @optipri has good information about dating these. Here.

    Description and Model of Stove

    This is tougher after a lot of reading I’m still pondering as I think others are. My model has the taller very old burner, the duelling blowlamps logo though sadly and curiously the Smiley face and the words ‘MADE IN’ are missing. If you look carefully and compare this logo with others you can imagine why the word ‘IN’ is not there as that line appears lightly stamped but why the face and word ‘MADE’ which are higher are not there is odd.

    The stove also has the AKTBOL A.B. Hjorth filler cap and the circular stamping on the fount base. The entire stove is made from brass, including the base and the pump rod. Lastly, it works after a bit of fiddling. Because of my calculated capacity 1.5 litres and the Ultraprimus 1 and 2A models having a capacity of 1.3 litres I’m leaning towards mine being some sort of variant of these. I think the jury is still out though.

    Primus - Copy.jpg Burner (Tall) - Copy.jpg Air screw - Copy.jpg Filler Cap - Copy.jpg Pump - Copy.jpg

    Stamp on Fount Base
    Stamp on Fount Base - Copy.jpg
    Dimensions and Specifications

    All brass construction throughout.

    Height 11”

    Fount base 7.169”

    Fount tank width 6.526” OD (165.760 mm)

    Fount height 2.8” usable (71.12 mm)

    Capacity 1.5 litre (my calculation)

    Filler Cap 1.182” diam

    Filler cap washer 0.900” diam

    Burner height 3.938”

    Burner width 2.208”

    Pump Tube 0.660” ID (17 mm)

    Pump Tube 0.755” OD

    Pump Cap 0.911” (knurled diagonally)

    Pump Knob 0.666” (knurled diagonally)

    Pump Rod length 4.910” (includes pump knob)

    Air screw width 0.710”

    Thanks and stay safe
  2. Tony Press

    Tony Press Australia Subscriber

    Jun 8, 2013
    Stinkpot Bay, Howden, Tasmania, Australia
    Very nice, Iain, and a great presentation.



    Edit: Exhaust pipe is often the correct diameter to make the flame tube with.