8 replies to this topic

[PyroKid]

Hey guys,

I know that one possible way of fusing category 3 material in order for it to be fired electronicaly would be to get a piece of quick match, and to cut slits into the casing of the quickmatch and then to place the e-match into the quickmatch.

I was wondering if it is at all possible to do this without having to use the above method in such a way that the delay is completely eliminated.

I would be more than greatful if anyone is able to help me with the above querie.

All the best

[Richard H]

In pyromusicals it is sometimes practice to place the electric match for each shell directly into the lifting charge bag, bypassing the shell leader altogether.

Similarly placing the electric match into the lifting charge of the first tube of the item would have a similar effect.

Doing this in practice is another matter. While you can refuse items on the display site without a licence I would strongly advise against doing so unless you have an intimate knowledge of the item you intend to re-fuse.

[Arthur Brown]

A lot depends on the construction of the deviceIf the timing fuse goes into the device then you are stuckwith the minimum delay from the accessible fuse. If the time fuse leads into a blackmatch leader then you can ematch into the leader. Dismantling the device without a licenced factory is contrary to MSER but there is an exception for fusing fireworks so adding a fuse is OK digging around in the device to find the prime point is NOT.

[alany]

I wouldn't stick the e-match into a shell lift bag. Some people do, but it is generally considered more dangerous that just cutting back the leader to an inch or so and putting the e-match into it, folding down the wires and taping off in the usual manner. If you are going to do it I'd leave the shroud on the match rather than pulling it back.

With an inch or two of leader any delay will be largely insignificant. If you are really desperate you might compensate with prefire delays in software. But pyro timing is just never that precise and doing stuff to music has speed of sound delays that are generally more of a problem than the hang-time of the cut back leader.

The real problem is smaller cakes that only come with visco fuse, you need to slip quickmatch over them and the delay is quite variable depending on how well you did it. Larger display cakes are fine, they typically come with double quickmatch leaders.

I think jitter in the delay is the biggest problem personally, not the absolute delay. If you scrunch up the leader on one shot more than another you can definately hear the difference. I guess it could be a serious problem if you are doing tightly sequenced fronts. I could, for example, see value in putting the e-match in the lift of mines that are going to be fired in such a manner.

[ChesterPFX]

As Arthur correctly points out, you could find yourself in trouble if you start messing about with the fuses of Cat 3 fireworks. To conform with Bs7114 a Cat 3 firework must have a fuse between 5 & 15 seconds. If you change this you may find your Cat 3 becomes a Cat 4.
If you need a fusing Exemption Certificate, contact the HSE up in the Wirral. (The Explosives Act 1875 (Exemptions) Regulations 1979, Certificate of Exemption No 4 of 1995)

[Richard H]

As far as I am aware you do not need the exemption now that MSER is law.

[Arthur Brown]

MSER Rules, almost/perhaps all other explosive statutes are replaced and rescinded by MSER

The Exemption exists WITHIN MSER You can fuse up to 10Kilos fireworks without any application form without a factory.

See http://www.legislati...05/20051082.htm look at 9.2.e

[ChesterPFX]

Well bloody hell; I hadn't got that far through the regs yet. That'll make life alot easier for some people. Cheers Arthur.

Edited by ChesterPFX, 28 April 2005 - 07:16 PM.

[BigG]

Please note that 9.2.e refer to fusing when you got an explosive storage. You may not fuse class 3 items as a member of the public with no license at all.