My first 6" multi-break shell

[lanschr0]

http://www.youtube.com/watch?v=qOmhuRuCZLQ

I ran out of rice hulls when i had reached this shell. I know the use of toilet paper for wading wasn't smart, but i launched the shell over a lake. Yes that is visco. I also ran out of time fuse.

This was my first homemade 6" ball shell. Wasn't the best but my next one will be better. This shell has 100g lift, 30g FP:BP mix for the first break, 20g FP for the second, and five 3/4" cylinder shells. All five small shells burst, but sadly in a cluster.

Please comment, and give me tips.

[Pyromight]

If you are planning to make another multi-break shell, I would encourage you to make the shell cylindrical, allowing for more inserts to be added and would have a better and easier placement, which can vary from however you like, popular multi-breaks are mixed of coloured shells and salutes. This shell was great for your first multi-break shell, and perhaps would have had a nicer and less clustered break if it were cylindrical. The reason why I say cylindrical is the better choice, is because they seem to be more common that most believe and if you browse on some of Dave's videos, you'll notice most of the rockets with excellent inserts, are in fact, cylindrical. I believe Nighthawkinlight is a good example for some multi-break shell making ideas. In one of his videos, he filled the entire shell with firecrackers, giving the effect of a beraq shell:


http://www.youtube.com/watch?v=7NiB32fscyQ&feature=plcp

Also the tutorial on how to make a Sun & Planets shell (also on his channel) is quite interesting and you can change up a couple inserts to create a different effect.

[lanschr0]

I thought about using cylindrical shells, but I wasn't sure how long to make the launch tube. Would I be able to use the same shell diameter to tube ratio? For example, for every inch in diameter you should use one foot of tube. What would i have to do, if i use three cylindrical shells that are stacked upon on another? Should i increase the tube length by three?

Thank you for the help. :)

[Chris H]

Most of the time people reserve the term multi-break for multiple full sized breaks launched at once, often all joined together. What you made might be more of a shell of shells or shell with inserts.

I don't know who told you that you need a foot of mortar per inch of shell diameter, but they're mistaken. Most people and literature recommend about 6x ID, or 6" per inch of diameter. If you look up any commercially manufactured mortar specifications, they will be around this value. With multi-break cylindrical shells this can get messed up, though typically only for relatively long shells. You can certainly fire a shell out of a standard length gun, but some people prefer longer mortars. You may want to look into the length of long guns that the PGI provides for competition. The issue with using a longer mortar than standard is that after you get everything worked out, it is specific for that mortar length. If you standardize a 5" shell to fire from a 60" mortar instead of the normal 30", you HAVE to fire it from a 60" mortar to make it work properly. If you tried it from a 30" mortar, you'd possibly end up with breaks going off on the ground. This generally necessitates you bringing your mortar with you everywhere, or having a similar sized mortar available at the shoot site. This is why I mentioned possibly wanting to look up the competition long gun dimensions. That way if you're used to firing from one, the same dimension will be available should you ever compete. If you tune everything to fire from a normal length gun, it will still work out of a long gun, but may go higher and have an increased likelihood of flowerpot.

[Pyromight]

I thought about using cylindrical shells, but I wasn't sure how long to make the launch tube. Would I be able to use the same shell diameter to tube ratio? For example, for every inch in diameter you should use one foot of tube. What would i have to do, if i use three cylindrical shells that are stacked upon on another?

It's quite rare to see a spherical multi-break shell. Majority are cylindrical. The length of the mortar, in this situation, would only depend on how many inserts you have. Let's say you wanted to make three breaks, whether you would want the simultaneous, or in succession would be your choice. A simultaneous break would result in all the inserts being at the same level in the shell, with the exact same length of time fuse. The idea is to fit as many inserts as you can into the shell and make sure that nothing will cause a flowerpot. Certainly, the breaking powder will need to be quite subtle and cannot be too powerful, otherwise, your shell will cause a cluster. I can't really get too in depth because it will cause a complete mess of text. Like I mentioned, Nighthawkinlight had a great tutorial on how to make a Sun & Planets shell, of course, you can create a different type of inserts, just keep in mind, the shell unfolds from the top to the bottom, not the other way around, seeing how it is an Italian type shell.

http://www.tms.org/pubs/journals/JOM/0407/Roncone-Fig3-large.gif

Try doing some research, there's great videos online showing the basics of it, if worst comes to worst and you haven't found anything, look at Dave's "Colour & Report shell in the making", just add inserts of smaller shells. The video is very interesting and has plenty of interesting techniques.


http://www.youtube.com/watch?v=UeAXU1DE5No&feature=plcp

[lanschr0]

Thank you! :)

[copper acetoarsenite]

Very nice shell a hybrid!!!! loved it

[copper acetoarsenite]

Just one small suggestion with a ball shell the inserts will be more clustered...you can try gluing stars in the casing in order to get more apparent spread...but using cylindical inserts, tourbillions, farfalle, serpents, bouquets etc...is perfectly valid another nice idea would be to add a few gold or silver crosette stars, if you have a pump and can safely make the crosette burst...regarding the visco...I admit I didn't work with visco extensively, but I think that due to the narrow core and side ignition capabilities a six inch shell is too big a risk...I would either use a spollette and top-fuse, or make Japanese timefuse with a paper core...the instructions for which can be found in Lancaster's Fireworks- principles and practice in the section by Dr. Shimizu [the manufacturing processes for Japanese fireworks]...or for safety sake just wait until time fuse available I think personally that visco is not the best for any shell above 2.5" maybe 3" but 5 and 6 is pushing it especially since it not dual fused or crossmatched and priming with bp/nc can damage the coreespecially when the solvent is amyl acetate...I don't know if you make your own NC or not, but even acetone can damage the core...I'm not trying to sound critical just my opinion but then again I was [I]extremely fussy about my shells...if you can afford a few pyrotechnica volumes the 'Fulcanelli' series is excellent in terms of cylindrical shell manufacture

enjoy your art good sir!!!

...

[PyroJoeNEPA]

If you run out of rice hulls you can use BP coated Rice Krispies. Seriously..no pun intended with the word rice. Light misting of water, dust with BP, toss, mist & dust again & let dry.

[Chris H]

I find brand name rice krispies to not be very good. They're too easy to get overly wet, and then they turn to sludge. I'd recommend a generic brand puffed rice cereal. This is not the same as rice krispies. The actual kernels are larger, and more robust. They will shrink when you get them wet, but they wont go to sludge, and they dry quite firm. They look like the following image:

http://www.naturalmentefarma.com/wp-content/uploads/2011/09/puffed_rice1.jpg

[copper acetoarsenite]

lol that's what I used to ue sometimes..but at the time i though I was so smart and original...NOT!!!..LOL...also blenderized and seived [i.e graded] corke pieces...save tose wine corks!!!...i couldn't get rice hulls..no skylighter...back in th days[although I'm only 33] all pyro chemicals and supplies came from surreptitious and clandestine means, stealing homemade...kno3...stolen from highschool kclo3 electrolysis...when i started there was no skylighter...when i look at that sight and others...i say if only!!!...hehehe

I really feel bad for those in certain 'nanny state' countries...who don't have anything...but someone can go to an autosupply shop, a pharmacy..and a few other places...and get enough material to easily to make quite a deadly IED...but the poor fireworkers can't even get a roll of visco...this world sometimes...ayayay

[copper acetoarsenite]

..but then again your idea for paper wadding worked excellently, so I guess there's more than one way to peel a potato...you had nice colors too I see that you spent a lot of time at the screen...also your round stars were flawless in your cylindrical break...really an excellent shell...I've had to rewatch your video...a few times now!

[copper acetoarsenite]

o ne last thing as I'm very ossessive the type of shell you made is known in Japanese as a 'pokamono' built different from warimono...having re-read shimizu's section on their manufacture your technique was quite close to Shimizu's recomended method...i guess that's why a viewd your video so many times...lol

[lanschr0]

Thank-you for your input. It is greatly appreciated, and I will have to try all of your suggestions, especially the rice crispys. lol