What is a good sized ball shell to build for the first time

[Indypyro317]

 

I’ve have a pretty good understanding of how fireworks work and how important safety is while mixing comps or assembling things from making salutes and have studied a lot of information on yt and Skylighter on shell and  decided to try the 8” tiger willow shells from skylighters website but scaled down I was planing on using a hot bp granulated with 20% water  the lift and the same for burst I thought this would be a good way to get into shells and talked to a few shell builder’s at club events and most suggested a 3-5 inch shell with charcoal stars and bp only burst wondering if I should pump the stars or cut them in the book pumped stars are used if I scale it down to 4 inch would 3/8 be a good star size and If anyone has good resources on shell building or experience I’d love to talk to you about safety or good advice for a beginner 

[Arthur]

First, never use a stainless steel bowl for anything. I've seen some comp burst into flames because the stainless bowl focussed the heat of the sun.

It's hard to make something good at a week or weekend event, there just isn't enough drying time, see whether there will be any supplies available on site.

Rice Krispies (yes breakfast cereal!) makes fine filler, and carrier for meal coated rice hulls. Sort out the fire seal where the time fuse passes from the lift cup to the inside. The Chinese use gluey string, but that may take a month to dry which is the time from the factory to the user via rail, and sea. you have one hour to be ready so maybe a big pile of hot glue will work (did for me!).

Ask every pyro friend for their measurement scaling. For every shell size, there will be an optimum star size, lift weight, and burst charge to carrier ratio. Every maker has their own ideas, start with their figures then you can revise to your own.

My first shell at a week event youtube.com/watch?v=z9XNUnbxo50

[Indypyro317]

6 hours ago, Arthur said:

First, never use a stainless steel bowl for anything. I've seen some comp burst into flames because the stainless bowl focussed the heat of the sun.

It's hard to make something good at a week or weekend event, there just isn't enough drying time, see whether there will be any supplies available on site.

Rice Krispies (yes breakfast cereal!) makes fine filler, and carrier for meal coated rice hulls. Sort out the fire seal where the time fuse passes from the lift cup to the inside. The Chinese use gluey string, but that may take a month to dry which is the time from the factory to the user via rail, and sea. you have one hour to be ready so maybe a big pile of hot glue will work (did for me!).

Ask every pyro friend for their measurement scaling. For every shell size, there will be an optimum star size, lift weight, and burst charge to carrier ratio. Every maker has their own ideas, start with their figures then you can revise to your own.

My first shell at a week event youtube.com/watch?v=z9XNUnbxo50

Thanks this will really help when I don’t want to transport a shell and want to make it on sight the main issue I see is the shell wrapping drying 

[Mumbles]

I think you've gotten some good advice on shell size.  I'd go no smaller than 3", but 4 or 5" would be good too.  Below that the techniques that work don't translate all that well to bigger and better things.  Granulated BP should work for any of those sizes, but may be kind of wasteful in a 4 or 5" shell.  I personally prefer a carrier for the burst in most shells, though admittedly I don't build many ball shells anymore and haven't used BP as a burst in a while.  I use KP or something similar most of the time since I found it hard to keep up with BP needs.

Building entirely on-site has it's own set of challenges.  I believe Ned used pumped stars for his 8" shell to help out with the drying time of the stars to address that one particular issue.  Cut or pumped either will work fine.  You may notice some erratic flight paths from the stars if bursting rather hard, but it still looks pretty.  On their own stars can take a few days to a week to dry.  With a drying box or a good hot day that can be accelerated if done right.  Same thing with the paper paste wrap.  If done with actual pasted paper, you're looking at a day or two.  With gummed tape, probably a few hours in a drying box or the sun will get the job done.  Overnight should also do the trick with some airflow.  In this regard, a 3" shell will require less paste wrapping there is so that may be an option to speed things up.  I typically do 3" all in one sitting.  A 4" may be pushing it, but a 5" I would personally do in two separate applications.  If there is a WASP on hand, that's all a moot point though and would also speed things up. 

If it's an option, the easiest way to do this is to make stars, BP, burst, etc. ahead of time at one shoot or a safe place at home.  Then assemble, paste, finish, and shoot the shell at the next shoot.   This is very doable if you have at least a Friday-Saturday schedule.  Still doable on just a Saturday, but you'll need a drying box or the weather to cooperate and start up in the morning.  

Another suggestion is for smaller shells, you may want to consider a little faster formula than tiger willow.  Stars with a longer hangtime can be problematic in smaller shells due to the lower burst height sometimes.  Chrysanthemum 6 (C6) or Chysanthemum 8 (C8) probably would fit the bill.  The "C's" from Shimizu are more than just formula names.  It's the ratio of charcoal to 10 parts nitrate.  Some of the formulas have been rounded off, but it's where they were based.  For reference, tigertail is the equivalent of C10, and Shimizu Willow is C12.  By blending them, Ned just made C11.    

 

[Indypyro317]

8 hours ago, Mumbles said:

I think you've gotten some good advice on shell size.  I'd go no smaller than 3", but 4 or 5" would be good too.  Below that the techniques that work don't translate all that well to bigger and better things.  Granulated BP should work for any of those sizes, but may be kind of wasteful in a 4 or 5" shell.  I personally prefer a carrier for the burst in most shells, though admittedly I don't build many ball shells anymore and haven't used BP as a burst in a while.  I use KP or something similar most of the time since I found it hard to keep up with BP needs.

Building entirely on-site has it's own set of challenges.  I believe Ned used pumped stars for his 8" shell to help out with the drying time of the stars to address that one particular issue.  Cut or pumped either will work fine.  You may notice some erratic flight paths from the stars if bursting rather hard, but it still looks pretty.  On their own stars can take a few days to a week to dry.  With a drying box or a good hot day that can be accelerated if done right.  Same thing with the paper paste wrap.  If done with actual pasted paper, you're looking at a day or two.  With gummed tape, probably a few hours in a drying box or the sun will get the job done.  Overnight should also do the trick with some airflow.  In this regard, a 3" shell will require less paste wrapping there is so that may be an option to speed things up.  I typically do 3" all in one sitting.  A 4" may be pushing it, but a 5" I would personally do in two separate applications.  If there is a WASP on hand, that's all a moot point though and would also speed things up. 

If it's an option, the easiest way to do this is to make stars, BP, burst, etc. ahead of time at one shoot or a safe place at home.  Then assemble, paste, finish, and shoot the shell at the next shoot.   This is very doable if you have at least a Friday-Saturday schedule.  Still doable on just a Saturday, but you'll need a drying box or the weather to cooperate and start up in the morning.  

Another suggestion is for smaller shells, you may want to consider a little faster formula than tiger willow.  Stars with a longer hangtime can be problematic in smaller shells due to the lower burst height sometimes.  Chrysanthemum 6 (C6) or Chysanthemum 8 (C8) probably would fit the bill.  The "C's" from Shimizu are more than just formula names.  It's the ratio of charcoal to 10 parts nitrate.  Some of the formulas have been rounded off, but it's where they were based.  For reference, tigertail is the equivalent of C10, and Shimizu Willow is C12.  By blending them, Ned just made C11.    

 

Amazing information thank you so much, and I’ve looked at c6 as a option as well as d1 glitter the comp for each are very similar other then extra stuff for the d1 I think I’ll order the stuff for all of it and decide when I start screening probably start with c6 or the tiger willow my only question is what is kp I read another forum on here that said it was a perchlorate based burst like flash or something different? And the advice for the club shoot was great might be what I do if it’s spoused to be hot out most of my clubs events are only a day so I’d be pushing the drying a little 

Edited June 27 by Indypyro317

[Zumber]

Kp is not flash burst.

KP is potassium perchlorate Charcoal based burst charge.

Any flash is considered to be booster not burst.

[Arthur]

3" shells often have a flash like booster in the burst powder, more proportionally in smaller shells, 4" shells may break with just good BP, Bigger shells will likely use an inert filler such as rice hulls or rice krispies as 20 - 50% of the burst charge weight. Separate the layers in your shell with tissue paper -this will hold all the bits in the right place til you pull the hemis together.

Ask the questions of your host or club that's organising the meet. IF it's a club event then ask if the club, or any member is bringing a Wasp shell pasting machine, be prepared to pay for the tape used!

[Indypyro317]

13 hours ago, Zumber said:

Kp is not flash burst.

KP is potassium perchlorate Charcoal based burst charge.

Any flash is considered to be booster not burst.

What’s the ratio I’ve never herd of this is it in any of the popular books on fireworking where could I find more info just searching the forum?

[Indypyro317]

9 hours ago, Arthur said:

3" shells often have a flash like booster in the burst powder, more proportionally in smaller shells, 4" shells may break with just good BP, Bigger shells will likely use an inert filler such as rice hulls or rice krispies as 20 - 50% of the burst charge weight. Separate the layers in your shell with tissue paper -this will hold all the bits in the right place til you pull the hemis together.

Ask the questions of your host or club that's organising the meet. IF it's a club event then ask if the club, or any member is bringing a Wasp shell pasting machine, be prepared to pay for the tape used!

I’ll have to see I know a couple memebers have them but I’ll have to see if they want to drag it to the meet most of the members live hours away 

[Arthur]

You could consider building a data file of things you need to know for each shell size, rise time, lift quantity, time fuse length, Spollette length. Burst charge ratio of BP to carrier. etc, etc.

[Zumber]

11 hours ago, Indypyro317 said:

What’s the ratio I’ve never herd of this is it in any of the popular books on fireworking where could I find more info just searching the forum?

Dr . Takeo Shimizu has written his book "Fireworks Art Science & Technique " 

He also has described the sensitivity of charge how to handle this charge.

But at this stage and this level you would better to play with black powder type charge owing to your own personal safety.

Though perchlorate charge is written safer you still read more about it from experts its safety measures and supervision. You dont play with it alone its my personal advice regarding safety.

I am not going to write down exact ratio here you may stick to just Black powder burst right now.

[Mumbles]

KP is a burst charge from the book Zumber mentioned.  It's included below for reference.  It's essentially a perchlorate based black powder.  It's not as easy to use as BP in my experience at least and takes some dialing in.  Perchlorate based compositions tend to be more sensitive to burn rate changes under pressure.  Due to this, KP and related burst charges, are a little more sensitive to shell size and appropriate paste wrapping.  Smaller shells don't always generate the required pressure for a proper burst, and larger shells can over do it.  Similarly, the amount of pasting has to be dialed in a little bit to make the walls strong enough but not too strong.  Weak confinement doesn't give an overly satisfying burst, and too much confinement bursts extremely hard to the point of potentially shattering or blowing out stars.  

To remedy this issue, there are 4 or 5 different bursts given in Shimizu's book that are suited toward different sized shells or different specific types of shells.  Unfortunately, the one best suited toward smaller shells is chlorate based, which I'd avoid for the time being until you're more experienced.  BP is by far the most universal and forgiving.  

Potassium perchlorate - 70

Charcoal - 18

Sulfur - 12

SGRS - 2

[Zumber]

1 hour ago, Mumbles said:

KP is a burst charge from the book Zumber mentioned.  It's included below for reference.  It's essentially a perchlorate based black powder.  It's not as easy to use as BP in my experience at least and takes some dialing in.  Perchlorate based compositions tend to be more sensitive to burn rate changes under pressure.  Due to this, KP and related burst charges, are a little more sensitive to shell size and appropriate paste wrapping.  Smaller shells don't always generate the required pressure for a proper burst, and larger shells can over do it.  Similarly, the amount of pasting has to be dialed in a little bit to make the walls strong enough but not too strong.  Weak confinement doesn't give an overly satisfying burst, and too much confinement bursts extremely hard to the point of potentially shattering or blowing out stars.  

To remedy this issue, there are 4 or 5 different bursts given in Shimizu's book that are suited toward different sized shells or different specific types of shells.  Unfortunately, the one best suited toward smaller shells is chlorate based, which I'd avoid for the time being until you're more experienced.  BP is by far the most universal and forgiving.  

Potassium perchlorate - 70

Charcoal - 18

Sulfur - 12

SGRS - 2

I have conversation with japnese technician for shells having size 6 to 12 inches they use Potassium nitrate, potassium perchlorate,charcoal and SGRS and cotton seeds as a carrier.

half or less than half of perchlorate amount is replaced with potassium nitrate for their burst charge.

this adds extra safety plus controls pressure for bigger size shells.

I have his formula in a diary.

 

[Indypyro317]

Been meaning to pick up a copy of fast and I’ll probably stay away from it at first especially anything with chlorate and sulfur I met a older guy that lost most of his hand mixing a similar comp when he was young 

6 hours ago, Mumbles said:

KP is a burst charge from the book Zumber mentioned.  It's included below for reference.  It's essentially a perchlorate based black powder.  It's not as easy to use as BP in my experience at least and takes some dialing in.  Perchlorate based compositions tend to be more sensitive to burn rate changes under pressure.  Due to this, KP and related burst charges, are a little more sensitive to shell size and appropriate paste wrapping.  Smaller shells don't always generate the required pressure for a proper burst, and larger shells can over do it.  Similarly, the amount of pasting has to be dialed in a little bit to make the walls strong enough but not too strong.  Weak confinement doesn't give an overly satisfying burst, and too much confinement bursts extremely hard to the point of potentially shattering or blowing out stars.  

To remedy this issue, there are 4 or 5 different bursts given in Shimizu's book that are suited toward different sized shells or different specific types of shells.  Unfortunately, the one best suited toward smaller shells is chlorate based, which I'd avoid for the time being until you're more experienced.  BP is by far the most universal and forgiving.  

Potassium perchlorate - 70

Charcoal - 18

Sulfur - 12

SGRS - 2

 

[Arthur]

Lancaster's book is still in print, Wiengart and shimizu's books are usually on Abe books or may be found online.

Avoid any formula that calls for chlorate, 'til you fully understand the likely incompatibilities. Sulphur is considered essential for BP used as lift and burst. Perchlorates have fewer incompatibilities than chlorates.

[Zumber]

5 hours ago, Indypyro317 said:

Been meaning to pick up a copy of fast and I’ll probably stay away from it at first especially anything with chlorate and sulfur I met a older guy that lost most of his hand mixing a similar comp when he was young 

 

Also have print copy of Friction and impact test result of various chemicals , incompatible materials lists......these two should be seperately printed and place it in your working area and read it every time before you attempt on any composition preparation.

Most of accidents causes because of Chlorates type composition and Flash powder type compositions.

Edited June 29 by Zumber

[Arthur]

There is no complete and correct list of all the fireworking chemical incompatibilities/sensitivities, unless you have written one.

The first rule should be to totally separate chlorates from any other ingredient or mixture. Just as a suggestion your first (few) fireworks should be BP lifted, BP burst, and contain effects including potassium nitrate, and potassium perchlorate as oxidisers. Totally avoid chlorates. Don't use calomel, realgar, antimony sulphide and the other heavy metal salts of old formulae, -they are too toxic for any entertainment purpose and have been superceded by better things.

Does the meet that you wish to attend have a supplies delivery to site? Maybe you could get something delivered by correct transport -even some stars. Does the club have a Wasp (or other) shell pasting machine? Can you buy tape on site?

[Indypyro317]

That sounds smart and I plan to stick with just charcoal based stars to begin with first I need to get a good bp down planing on using red cedar or yellow pine and using granulated bp for the lift and break 

On 6/28/2024 at 11:16 PM, Zumber said:

Also have print copy of Friction and impact test result of various chemicals , incompatible materials lists......these two should be seperately printed and place it in your working area and read it every time before you attempt on any composition preparation.

Most of accidents causes because of Chlorates type composition and Flash powder type compositions.

 

[Indypyro317]

I was planing on a tiger tail or willow star with granulated bp for burst and lift made from red cedar or willow charcoal 

[Zumber]

40 minutes ago, Indypyro317 said:

I was planing on a tiger tail or willow star with granulated bp for burst and lift made from red cedar or willow charcoal 

Thats great...!!

Remeber you have to make charcoal stars correctly otherwise it wont function well, pine charcoal would be great.

Just mixing ingredients and forming stars out of it will not work ,also it has tendency of driven In ( star dry outside only and not in center).

You have to ball mill these  compositions and use 75/25 water alcohol. Pumped (pressed stars) works well and also these stars lit readily but still you can just prime it with screened bp.

[pyrojig]

Another technique is to press a star with a void in it to aid drying, like a crossette star. The driven in problem is an issue in bigger , or high charcoal content stars. The void helps dry center more evenly. Good for events . “Build on site type. “

It’s nice to see some excellent posts on the site and not trolls polluting the site

[Indypyro317]

On 7/4/2024 at 1:38 AM, Zumber said:

Thats great...!!

Remeber you have to make charcoal stars correctly otherwise it wont function well, pine charcoal would be great.

Just mixing ingredients and forming stars out of it will not work ,also it has tendency of driven In ( star dry outside only and not in center).

You have to ball mill these  compositions and use 75/25 water alcohol. Pumped (pressed stars) works well and also these stars lit readily but still you can just prime it with screened bp.

Ball mill charcoal tailed stars? Someone else just told me not too

[Indypyro317]

On 7/7/2024 at 10:14 PM, pyrojig said:

Another technique is to press a star with a void in it to aid drying, like a crossette star. The driven in problem is an issue in bigger , or high charcoal content stars. The void helps dry center more evenly. Good for events . “Build on site type. “

It’s nice to see some excellent posts on the site and not trolls polluting the site

That would be interesting to try I could press the stars then press a small center hole like a crossette

[Zumber]

21 minutes ago, Indypyro317 said:

Ball mill charcoal tailed stars? Someone else just told me not too

I already have mentioned that just screened mixture wont work well due to high charcoal percentage.

You just ball mill it So that mixture gets mixed well and perform better.

The stars are relied on air oxygen for its function.

Use alcohol and water 25/75 to bind stars.

[Zumber]

33 minutes ago, Indypyro317 said:

That would be interesting to try I could press the stars then press a small center hole like a crossette

It would be time consuming and suitable for comets.