Jump to content
APC Forum
Get A Password Reset Email From Us? Please Read This.

spitfire's Blog

A blog by spitfire in General

  • entry
    1
  • comments
    5
  • views
    2386

Tailing bombettes and other items

spitfire

Entry posted by spitfire

1506 views

 Share

What is a bombette in the first place? Simply a tube shot from a small mortar, like we see in commercial cakes linked together to shoot 12, 19, 30 shots one after one. Each shot tube contains a slightly smaller tube containing a clay plug holding the delay fuse, stars and flash burst. When they are fired we see a colored rising tail. Red, green, gold, glitter, silver... followed with whatever is inside the bombette. Making this tail is rather simple, but not obvious.

 

NOTE: this blog only considers the tail compositions and how to apply them, i am not going into details about the bombette itself.

 

The starting materials are the empty bombette casings, with the timefuse (homemade visco, but commercial will do just fine too) and clay plug already in place. Looks like this from the other side, where the stars and burst will be later on:

 

2879-bombette3

 

If we flip this bundle we see practically the same, but the clay plug is closer to the end of the tube, just 5 - 7mm space is left. This space is going to be filled with the tail composition.

 

Here's the trick: you'll need NitroCellulose laquer to make your tail composition into a pourable slurry. Water/alcohol based dextrin slurry won't work. It destroys the fuse and forms a weak crumbly mass. Use any star composition you like, just leave the Dextrin out and mix it with the laquer untill you have a pour-able slurry resembling the viscosity of honey. Working with this slurry is rather tricky with a spoon or whatever, so i make batches of 300g and pour it in an empty dish-wash soap can. They have a neat little squirt cap, ideal to portion without spilling! And you can save the rest for a next time. Take your bundle of bombette casings and start pouring some slurry on top and around the fuse. Don't use too much, a teaspoon-like portion is enough. Before they form a dry film (that would be pretty fast) dip them in some fine grained BP to ensure ignition. Set aside and let dry! It should look like this now

 

2900-tailed-bombettes

 

After drying they are ready to be filled with whatever you where planning to fill them with.

 

Enjoy your colored tails!

 

  • Like 1
 Share

5 Comments

Recommended Comments

AdmiralDonSnider

AdmiralDonSnider 30

Posted

I like the idea of using NC binder, it should indeed provide better cohesion. In my limited tries so far, I had many dextrin bound tail portions disintegrating when lifted. I bet the Chinese use phenolic also here.

Link to comment
Dean411
Red gum binding works very well and is cheaper than NC, with dextrin bound comps I use gum arabic in solution and apply the rising tail comp with a little preassure and have had great success.
Link to comment
spitfire

Price might be something to consider, i happen to have a almost free source of NC... so that's why i use it a lot.

Link to comment
TomasBrod

TomasBrod 5

Posted

Water/alcohol based dextrin slurry won't work.

For me, water based star comp (with wheat flour) pressed in the cavity as tail rising effect works all right. My inserts are smaller (15mmOD), however. And I use the tail composition as delay directly.

bmb-15-wfc-sgal-m1.mp4

Link to comment
×
×
  • Create New...