First fire

Pb Azide (LA), which is the most important expl used in detonators (Ref 11), although extremely sensitive to shock, heat, and friction, is not sufficiently sensitive to stab action to insure 100% reliability in firing from the stab action. Consequently, the priming mixt is used as a first-fire layer in these units. RDX (cyclotri-methylenetrinitramine), also known as Cyclo-nite, is contained as the output charge of the typical stab detonator. Its output results in a detonation of other expls (Ref 11)... 

J.A. Carrazza et al, Development of a Safer Intermediate and First Fire Formulation for the M49A1 Surface, Trip Flare , PATR 4636 (1974), AD 784 066 / 3 GI 84) R. Kwatnoskl, Drag Reducing Fumer for Application in Small Arms Ammunition , FA-R-3003... 

Chlorate-sugar is one of the best of the first fire or igniter mixes. It bums very rapidly, with a yellow-white flame, and generates sufficient heat to ignite all homemade incendiaries mentioned in this handbook. 

Several igniters or first fire mixes can be set off by a spark from time fuse. Others require a stronger flame. Time fuse, plus matches, can be combined to provide this more intense initial flame. 

Napalm will keep well if stored in a tightly sealed container. It can be ignited with a match or any of the first fire mixtures described previously. The ignition packet should be placed adjacent to or just over the napalm, otherwise the petroleum may soak it and prevent its burning. 

A good source of ready-made thermate is the U.S. military AN M-14 Incendiary Grenade. To remove the thermate, first pry out the fuse assembly with crimpers or other nonsparking implement. See Figure 61. The reddish-brown caked substance on top of the contents of the grenade is a first fire mixture and it is spark sensitive. This should be broken up and the grayish powder beneath, which is the thermate, can be poured out. 

The first fire retardant polyester containing a reactive fire retardant monomer was introduced by the Hooker Electrochemical Corporation in the early 1950 s containing chlorendic acid as the reactive monomer (6). This pioneering development rapidly led to the introduction of variety of reactive halogen and phosphorus containing monomers, such as tetrabromophthalic anhydride, chlorostyrene and tetrabromobisphenol A, which found application in a wide variety of condensation polymer systems. 

Figure 11.21 depicts the behavior for a neighboring item when becoming involved due to an initiating first fire. The first fire could be a fixed gas burner as in a test or a fully... 

Ignition compositions Hot solid or liquid particles are desirable in igniter and first-fire compositions to insure the transfer of sufficient heat to ignite the main composition. Fuels producing mainly gaseous products are not commonly used. 

A slower-burning mixture is preferred over a more rapid one. The slower release of energy allows for better heat transfer to the main composition. Also, most "first fires" are pressed into place or added as moist pastes (that harden on drying), rather than used as faster-burning loose powders. 

Potassium nitrate is frequently used in igniters and first fires. Compositions made with this oxidizer tend to have low ignition temperatures (typically below 500 C), and yet the mixtures are reasonably safe to prepare, use in production, and store. Potassium chlorate formulations also tend to have low ignition temperatures, but they are considerably more sensitive (and hazardous). ... 

Compositions with high ignition temperatures (i.e., above 600°C) can be difficult to ignite using solely the "spit" from a black powder fuse or similar mild ignition stimulus. In such situations, an initial charge of a more-readily-ignitible material, called a "first fire," is frequently used. The requirements for such a mixture include [ 3] ... 

Reliable ignitibility from a small thermal impulse such as a fuse. The ignition temperature of a "first fire" should be 500°C or less. 

Figure 10 X-ray diffraction of films on SrTiOs with metal composition Bi4SrsCasCu4 (a) Directly heated to 850°C for 10 min the peaks correspond to the BLjSrjjCajCugOg phase, (b) First fired at 500°C then same as in (a) the peaks correspond to the phase Bi2Sr2CuOe.

First-Fire Composition. It is usually a mechanical mixture of an illuminating compn with BkPdr, as was defined under item 3. However, for certain items, it may be a special composition which is nonhygroscopic, easily ignitable mixture with high-burning temperature (Ref 37, p 6)... 

Accdg to Ellern (Ref 57, p 189), the terms "first fire" and "starter" refer in pyrotechnics not to the "prime ignition" but to the "intermediate ignition" source which is located between "primary initiation "and the "main pyrotechnic item , such as flares, signals, etc. 

Pyrocore, manufd by DuPont Co. It consists of metal tubing 1/8 inch or less in diam filled with combined explosive and ignition mixture, 4-40 grains per foot. It is claimed that even coarse commercial Thermite can be initiated from Pyrocore if Alclo Pellets (A1 35, K perchlorate 64 vegetable oil 1%) are used as a starter or as a first fire (Ref 57, p 191 and "Explosives Specialty Manual" E.I. duPont de Nemours, Wilmington, Delaware. ( Not listed in alphabetical Index of Ref 50)... 

The oldest and still widely used in pyrotechnics and fireworks "first fire" and "starter" mixture is BkPdr. It belongs to mixts without metallic ingredients. Metallic mixts contain combustible powdered metals, such as Mg, Al, Zr etc. Metalloids B and Si are considered metallic fuels because of their similarity in pyrochemical behavior to metals. Although BkPdrs are described in Vol 2 of Encycl, pp Bl65ff, we are giving here as Table E compns of three formulations used in pyrotechnics, as described by Ellern (Ref 57, p 375)... 

The rule should be to keep the more hazardous mixts at minimum size. Transfer lines (such as fuses, quickmatch, etc) between prime ignition and first fire are regarded as a part of the secondary ignition system... 

When used with highly compacted main pyrotechnic items, such as flare candles the "first fire" is either pressed (in dry form), or painted (in paste or slurry form) on top of item. For initiation of solid proplnts, a "first fire " mixt can be ignited if confined in a tube or capsule so that the hot gases will be spread over a larger surface area (Ref 57, pp 189 91) Table F lists various formulations for "starter mixtures" Table G for "ignition mixtures" and Table H for "first fire mixtures". -These formulations are given in Ref 57, pp 377-83. Some mixtures are taken from Ref 44a,... 

It may be mentioned that the same mixtures that are employed as first fires "(See Table H), may also have certain applications in "heat-producing cartridges" or "delay trains Conversely, a "delay"or a "heat powder" mixture... 

Formulas 64, 65, 66 67, designated as "Miscellaneous First Fires" are taken from Ref 44a, p 280, while other formulas are from Ref 57, pp 379-80... 

Formula 168, designated as "First Fire for Illuminating Flares" contains binder Laminae 4110 or 4116 with 1.4% catalyst Lupersol DDM. Used in pressed-on form as the final igniting mixt in many illuminating flares and illuminating candles... 

The compositions of typical igniter, first fire, and starter mixtures are also given in Table 5-29, p 5-48 of Ref 54. This Table is reproduced here as Table I ... 

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