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Crossette break charges


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Posted (edited)

As a proud owner of a new 1 1/8" (cruciform) crossette pump from Wolter I´m currently gathering information about the break charges (the search function didn´t help much).

 

I know there is a variety of options, including traditional techniques such as tied shots, which could probably be adapted for use in cruciform holes also. Some have reported that they had good results with flash powder in powder form, others deny that and vote for granulated whistle. Traditionalists have some good points to vote for dark report comps.

 

The topic of how to reliably ignite the break is also a point of controversy. Many US based masters seem to vote for thermalite (so does e.g. a well known US pyrotechnist in his crossette videos), but I assume that no European has ever managed to get a hold of this legendary stuff. Others vote for blackmatch or simply rely on the "spark jetting".

 

What´s your choice and why? What would you recommend someone who wants consistent and reliable performance? Looking forward to hear your opinions.

Edited by AdmiralDonSnider
Posted

ADS,

 

I can only speak from the commercial side as I have been involved with saving and re-building wet canisters full of crossetts.

 

These commercial crossetts use a round flash hole with a thick (.006) chipboard disk pressed into the hole then pasted well with three turns of 30-50 pound kraft. The break is standard 70:30 flash with a sensitizer. There are no fuses, thermalight, match or other methods of transfering the fire, just a 1/32" hole 1/4" deep into the crossette.

 

I'll post a pic later of one that was unwrapped.

  • 2 weeks later...
Posted

ADS,

 

I can only speak from the commercial side as I have been involved with saving and re-building wet canisters full of crossetts.

 

These commercial crossetts use a round flash hole with a thick (.006) chipboard disk pressed into the hole then pasted well with three turns of 30-50 pound kraft. The break is standard 70:30 flash with a sensitizer. There are no fuses, thermalight, match or other methods of transfering the fire, just a 1/32" hole 1/4" deep into the crossette.

 

I'll post a pic later of one that was unwrapped.

What is a sensitizer ?
Posted

PM sent.

 

Thanks Dag dry2.gif , don't share it with the foum.

Posted
No intention of doing so... :whistle:
Posted

No intention of doing so... whistle.gif

 

Why not? Has it somthing to do with flash? 2ninja.gif

Posted

Why not? Has it somthing to do with flash? 2ninja.gif

 

can you not read

The break is standard 70:30 flash with a sensitizer

 

so yes the information you seek has something to do with flash lol

Posted

LOL! So sorry, didn't see the sarcasm!

 

Yes, there are reasons... Lets leave it at that. :whistle:

Posted
It seems that the old "dark flash" was used inside crossette shots. What about filling it into the cavity as is?
Posted

I have had good success with 70/30 and a piece of blackmatch (as long as possible so it can´t move to and fro in the cavity).

Adding blackmatch isn´t much work and ensures the fast ignition of the 70/30 whithout any sensitizer.

And because 70/30 burns very fast the flashlight does not really upset (please excuse my english).

Posted

It seems that the old "dark flash" was used inside crossette shots. What about filling it into the cavity as is?

 

Fulcanelli tells of using regular flash for crossetts, I dont know if dark flash was used or not.

 

It seems a lot of guys are using black match for fire to the flash, I can only tell you that all of the commercial ones dont have any helpers.

Posted

Fulcanelli outlines the whole traditional crossette manufacture and breaking method on pg 21-24 of Pyrotechnica XI.

 

I've still yet to find a perfectly reliable method. I've been working on rolled shots however. I have a good feeling about it. I just haven't gotten a chance to iron out the details.

 

I tried just filling the cavity with dark flash and a stick of blackmatch. It worked, but I didn't get 100% breaks. There was some jetting. I think I needed more confinement. I used gummed tape, which was probably a little too short. I think pasted paper might be the trick. The way they were jetting gave me the impression they were blowing out the top, not the bottom.

 

Someone recommended taking the tooling and grinding the nipple on the end to a point. I guess it's kind of like a spolette now that I think about it, and it may help to spray more fire.

 

I've also looked into homemade imitation thermalite. Real thermalite and 70/30 works quite well. It works fine for silver streamers and glitters where the bright flash isn't as noticeable.

Posted

It seems that the old "dark flash" was used inside crossette shots. What about filling it into the cavity as is?

 

Fill the small hole with BP granules, 4FA or a bit smaller, maybe pulverone works too. Press the BP in it with a skewer or something.

For a 25mm crossette I use 0.5 grams 7:3, depending on the type of composition and burnspeed.

Close the top with grayboard, and give the comet 2 turns of 80 grams pasted kraftpaper.

  • Like 1
Posted

Thanks for your responses.

 

The traditional shot seems to be less suitable for the tiny cavities cruciform pumps make. In contrast, if you take a look at the cylindrical pump design Fulcanelli describes, this leaves room for quite a "large" shot.

 

Talking about unconfined flash: is a cardboard disk (placed above the shot hole) necessary for the flash to work well? I´m asking this because my pump doesn´t produce the small, squat (intended for a tiny disk) cavity which other pumps feature.

Posted

You don't need a squat, just place/glue the disk on top, maybe it'll work even without a disk. Rich wolters crossette holes are a bit on the small size compared to traditional Chinese pumps.

Granulating the flash is even better by the way ;)

Posted
What kind of solvent would be used when granulating flash? And what kind of binder?
Posted

Granulating the flash is even better by the way ;)

 

Do tell! How would you do that?

Posted
A little paste from sgrs, then add a tiny little to your flash, mix well and then push gently true a 1.5 or 2 mm screen.
Posted
Oddly enough, I've heard that the "traditional" Chinese pumps were actually ripped off from Rich. They probably enlarged the cavity to use a slower, cheaper break charge.
Posted

I've only ever 3/4" crossettes with a Wolter pump. I use a fuse (thermalite substitute from Tony Petro in one of the Pyrotechnica IIRC)

My break charge is one scoop from a (reloading kit) of fine ~40mesh BP and 1 scoop of 70/30. (I can't remember what size scoop (0.5cc ?) and all my stuff is put away ATM)

I then glue a disc on top and wrap with 2 turns of 60lb paper.

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