18 replies to this topic

[bernie]

I have always admired crossettes. Either shot as a single unit out of a tube or in a shell. They are so darn tedious to make it intrances me. I even have a video or two on the subject I bought from American Firework News a few years back.
Anyhow..... any of you UK pyros fiddle around with the things? What kind of success as well as failures did you have?
How about formulas.
In the event USA and UK terminollogy differs.... they are a pressed comet normally of a charcoal composition(ease of ignition) with a cavity shaped like a star to insure they fracture in four equal segments from a small amount of flash dumped into the cavity.
Any takers?

[robert johnson]

Failures what do you mean I only have a 100 % sucess rate. Accuracy in crossette comets is down to Fractions of a second. very time consuming to create but extremly worth the time it does take. I think streaming comets look great much more so when they break into 4 pieces all together.Flash dumped into the cavity I think not ,may be carefully placed in the cavity then a card disk is placed on top and then wrapped in kraft paper.

[bernie]

My fault. Was not specific enough. Of course we stick a disk on them and paste wrap the little buggers. Was just trying to get a feel for what you guys do over there.
In a seminar given by a guest speaker a year or so ago on the subject of crossettes.....Tom DeWilly a manufacturer
demonstrated a rather easy approach. This accomplished pyro uses a magnesium
based flash to break his cross. A rather fine mesh size. Under 250 anyhow. Before you chastize me please consider that he makes indoor pyrotechnics for a living. Close prox. stuff. The thing that really stuck in my mind was his pasting method. A self stick label. How easy is that. He demonstrated it. I saw it work.


Robert....a streaming comet is? Different lingo you know. Alum.? Charcoal? Glitter comet?

[robert johnson]

Streamer or charcoal streamer comets,Although it may sound like I only use one formula for charcoal stars. I mainly do, and that is the one in the golden brocade link, because once you have seen this formula working in a star /comet I think you will agree how superb it is. However it is incredabily filthy to work with but the results are well worth the mess.
the flash that is used is a mag flash using grade 6 mag /potassium chlorate made in a ratio of 50/50 not 70/30 as in the case of ally flash. the disks I use on top of the comet are very thin ply which is punched from a sheet of the material. to get all the comets to work accurately in their timing is where the skill comes in, which is done by total accuracy when making the length of the comet.
Another method Tthat can be usewd instead of kraft paper for the sealing is to use 45mm ally tape which also works very well and makes the comet ready to use straight away.

Cheers Rob

[bernie]

Mr Johnson,
sounds like you got it nailed down pat.
Traditionally the italians used a "dark" report to break their cross.Also a KCLO3 based shot. I have always had good results w/ 7-3-1 perc. based flash. The ally
tape is new to me though I suspect it is what we/I would describe as alum. duct tape here in the states. I'm gonna give it a try here before long. Thanks for the tip.
Back when I used to paste wrap I would give my comets a light coat of spray paint.
The fast dry kind. Spray laquer would give the same effect. It would seal it just enough so the exterior of the charcoal comet wouldn't make a mess of the paste wrap.
The timing issue is easily resolved if you use the comet pumps that I use. Interested? If by chance your not familiar with this style you are really gonna like this. Does the pump that you use have the nifty little star pattern cavity former that enables the comet to "crack" into four equal pieces?

[robert johnson]

Indeed sir it does.Made the pump myself on the lathe .I have seen some tooling where the shape is correct but unfortunately no taper has been put on the crosette forming part, you only need a gentle taper,just enough to make the comet slide off the tooling rather than trying to pull it off,which will more often then not crack the comet or if not will certainly weaken it.

[bernie]

Made a few pumps myself.Not being a machinist I was not able to figure out how
to make that nifty cross shape. The pumps
I made were exploding cavity comets/stars.No milling machine, just a swell old lathe that I can spin stuff around on.
Got wise and bought my pumps from a fellow named Rich Wolter. He IS a machinist and his pyro tooling is a beautiful thing to behold.
it's a pleasure to be talking pyro.

[Richard H]

Rich's tools are the best IMHO, I'm very tempted by his crossette tooling, prices are VERY reasonable too.

[bernie]

dont you ever sleep. pyros are insomniacs I hear:P
IMHO??????

[Edited on 21-4-2003 by bernie briden]

[bernie]

They are dreamy. For what it takes to make the things its a bargain at twice the price. Of course you can put yourself in the poorhouse buying every tool that looks like a new adventure. Making tools no matter what they might be can be half the fun.
PYRO DREAMIN'
PS ever make a tool for corning bp?
Go to sleep and read this later. You are getting sleepy,very sleepy:D

[Edited on 21-4-2003 by bernie briden]

[robert johnson]

Their you go, that was a non machinists reply.if you dont have the correct machine you can not do the job correctly, The shaping on the crosette pump is not possable to do without a milling machine or attachment, but if you do have one and put the time in to make one you end up with correctly made tools for the job you want to do and are not limited by some one else's work.Very easy to do and the pump and sleeves can be made for the size that you need to make or fire.

[bernie]

I do furniture upholstery. Been doing it for 25 years. Pretty good at it. Not the case with machine tools. I generally undertake things for the challange. It then becomes clear I should not quit my day job.
I have made a 3/8" star plate which works pretty good considering that I made it. If you take into account the hours put into it I figure it's worth about $ 700.00. American currency.
I also have a neat little tool I conceived which makes 7 - 7/16" cylinder stars at a time. The sleeve looks like a cylinder from a revolver. I like that part. It has very limited applications due to it's low productivety. It is real handy for making a small test batch fired from a 13mm tube. I usually just reserve a small portion from the larger batch of star comp. Because I ram these on an arbor press 4-5% water makes for a fast dry time. Test firing requires only 2 grains of Goex FFg. I can shoot them in the back yard. No complaints.
Over here in the states we ALWAYS shoot fire works in the nude. How about over in the UK? We wear hard hats of course.

[brocade]

Crikey and I thought the police would arrest you in the USA for going around with no top on. However it appear's if your doing nude fireworks your ok, it could bring a whole new meaning to the term im just going light my big rocket

Glad to see you think saftey first and don't forget your helmet.

[robert johnson]

I allways fire my displays in the nude I can not think of any other way of doing it. Like you I like to think my helmet is well protected from stray sparks.
I allways find firing large firework displays in the nude much easier, as I have found some where else to stick the portfires.You just have to be careful not to sit down until the end of the display or fart either..

[bernie]

You boys over in the UK don't even want to know how/where/what we hold our torches or fusies or portfires or whatever the heck you Brits call the the darned things. Full monty is the only way to go.
This is gonna turn into a Benny Hill show if we ain't careful.
The very first time I ever seen a pyro show up close and personal it was an intentional low level(yanked out a little bit of lift)show. The whole darn thing was ......
can't find the words....it ended up with two very pretty brocade shells(12") that just hung in the sky forever.I almost tried to reach up and touch them.It was astonishing. It almost brings a tear to my eye to think back on it. God help me I do love this so much. Gonna go blow my nose
I'm so worked up. Hooooonk, hooonnnk.
It's easy to forget sometimes. Remind yourselves by looking in on the spectaters. Joy. Pure joy.Might as well be doing it in the nude.