3" First multibreak shell working well

[Aspirina]

This multibreak shell is the first that works well for me. Divided into two floors: the first carries a ring with 10 explosions of 1g flash powder of which not all exploded (I think in the break, some exploded, sounds too strong to be just black powder ) the second floor contains blue stars (copper carbonate ) and a final bottom shot of flash powder 2g. I use black powder and 3g flash powder for break

main fuse: 2s

secondary fuse: 1.5s

reports: 2s

bottom shot: 1.5s

( Approx )

Total weight: 160g

Lift: 17g

http://oi63.tinypic.com/ncfjpv.jpghttp://oi64.tinypic.com/hrwyme.jpg

http://oi67.tinypic.com/fwmzgx.jpg

I hope you like this

I hope you like it

Video (Launch 1:15):

https://www.youtube.com/watch?v=d-vB9IwRwzw&feature=autoshare

Edited April 19, 2016 by Aspirina

[Zumber]

Very very nice..!!

[memo]

looks good to me , multi break succes

[PiroArt86]

nice shell!

[Aspirina]

thanks guys

[Wiley]

Aspirina, a few comments, if I may.

 

First off, I liked the look of it! I was expecting all the reports to ignite, then to see the second break open, but it was cool to watch the reports explode around the pretty blue break., rather like a sun-and-planets.

 

If you want to make under-sized bottom shots like that, roll your case with and close with a set of solid disks. Place the report in the bottom of the casing, fuse up of course, and ram sawdust in around it. Lightly dampening the sawdust with denatured alcohol (NOT isopropyl) will help it pack denser and grip the bottom shot better. When I say ram, I mean using a dowel and a mallet to beat the sawdust into a solid puck around the report. The report will want to rise up as you do this, so be sure to keep it pushed down to the bottom of the case. Once the sawdust is rammed up to the top of the report, allow all the alcohol to evaporate before filling with stars and burst.

 

The rice hulls in the bottom of such a shell are a big no-no. They create a soft spot on the bottom of the shell, which if it caves in will ensure a large crater in the ground. Doing what I described will eliminate that problem.

 

To keep the spiking from pulling the fuse to one side so badly, you could try off-center spiking. This page describes it better than I can https://sites.google.com/site/spamento/home/inserts/priming/loading-the-shell/breaking-the-shell-the-right-way/spiking-your-shell The only thing I don't like about what Dag describes is tying off the spiking string. Just use a half hitch like Ned shows here:

 

https://youtu.be/w70L6-4aCRc?t=241

 

If you're stacking the 1st break on without spiking it fully first, a better method is the one described in Fulcanelli. Spike your 2nd (bottom) break with longitudinal spiking only. Now take your empty 1st break case, which has a hole in in the bottom disk, and stack it on top of the bottom break. Fill the 1st break with stars and burst, then close it as normal. Spike the 1'st break onto the 2nd break, making sure to lay the longitudinal spiking in between the longitudinal spiking on the 2nd break. Now, beginning from the bottom of the shell, wind on your circumferential spiking such that you make "little squares" on the sides of the shell. When you get to the joint between the two breaks, make sure to create a wide band of closely laid string. This acts as a fire block, and snaps the first break's spiking when it bursts. Continue with the little squares up to the shell top, and tie off with a half hitch.

 

Here's a picture of shells made this way.

 

 

 

In my experience, visco will not function reliably for this sort of thing. You want to use time fuse and spolettes. I've taken to using drilled-back spolettes wherever I can on mine. Rings of 6 inserts all explode within .07 seconds, and first breaks can be made to go off as early as .5 seconds, though I prefer 1 second for complex shells.

 

Lastly, what's on the bottom of the shell? It looks like there's something else there in addition to the lift charge.

 

Excellent first effort! I look forward to seeing more.

Edited April 21, 2016 by Wiley

[Aspirina]

Wiley, thank you for devoting so much time to make such a constructive reply
I liked the idea of sawdust, had never thought of, but you close the shell with wet sawdust even alcohol?
I will consider the next time put rice hulls in the top of the housing, I did just the opposite of you're saying, to make it more compact hahaha I will try the method of spiking you recommend me, I really like this, and thanks for the tips for spiking, for the day June 24 (san juan) I have thought about doing many shells, I going applie them all the advice.
If I understand correctly as you do it, you light the fuse from the top of the shell? Or you light it in the bottom with the ignition of lift charge?
What you ask me, that red thing you see on the bottom is duct tape, it is only a protection, I have always afraid that the lift charge break the shell, is that tienenden first to break the bonds between cover and body.
I use visco for time reports to save me money hahaha I have not much fuse that use I use for espolets
And one last question, because not denatured and isopropyl yes with the sawdust?

 

pd: if certain things are not understood, sorry, tell me what it is and I will try to explain again the best I can

a greeting from Spain Wiley!

[schroedinger]

Aspirina, skip that duct tape, you allready paste the whole shell in with 3 turnsmof paper, that is enough protection.

If you use sawdust with alcohol, you have to think like:

Sawdust is all i need and i need to pack it tightly. To do that i ram it into the voids. That works but takes a lot of effort, but if i wet the sawdust it pacms much easier. Alcohol evaporates fast, so pack it with alcohol, wait for the alcohol to evporate and I'm left with perfectly packed sawdust.

 

For leveling in the shell just use a fine polverone, but in a 3" the hul, don't pose a problem.

 

Also remember that timefuse costs less then 1 eur per meter, not a god point to skimp. In this size of shells, if you can get it, you can also use wanno 3mm time fuse.

[Mumbles]

If you're just leveling a shell, you really should use coarse polverone. Otherwise it can settle in a shell during storage or handling and generate weak points.

[Niladmirari]

Good instructional video. http://yoursmileys.ru/tsmile/rulez/t2043.gif

[Wiley]

Aspirina, I didn't even notice the first time around, but your shell was made with the fuse in the lift. That's never a good practice with multibreaks of any caliber. All multi's should be top-fused. Failure to do so will result in the afore-mentioned crater.

 

Rice hulls should not be used in cylinder shells at all. They are by nature compressible, and you do not want compressible shells. Cylinder shells derive their integrity from the rigidity of their contents. Adding a soft, springy component like rice hulls can result in a non-rigid shell which has a much higher chance of failing than a properly constructed one. Use polverone to level breaks off, as others have recommended.

 

Duct tape is also not necessary. If your shell was pasted in properly, with 3 turns of 70# paper and good quality wheat paste, that duct tape will not do anything for you anyway.

 

Take a look at how this shell was built. All the photos titled "Building the 'Murica Shell" are of the same shell.

 

http://www.amateurpyro.com/forums/gallery/image/3228-building-the-murica-shell/

 

This is essentially how I make my multibreaks to this day, but without all the masking tape, and I tend to use 3 strands of thinner string.

[Aspirina]

Thank you all for the answers I to become clear, will not use more rice hulls to fill the shells... In the next few shells I will put into practice the Sawdust and alcohol method also try to light the shells by the top.

Use standard cardboard is a good choice for use like a fire-shield?

Here you have a video with a better sound:

http://www.pyrobin.com/files/VID-20160417-WA0009.mp4

And here a pic of the spiking without withe glue:

http://www.pyrobin.com/files/spiking.jpeg

[Mumbles]

Have you considered using a full sized bottom shot? I know it draws more attention. It's a little difficult to tell your bottom shot in the shell above from the rest of the salutes. If you move to larger shells, a full sized bottom shot helps with shell integrity, and helps it to survive the lift as well.

[Wiley]

 

Use standard cardboard is a good choice for use like a fire-shield?

 

 

Not quite sure what mean here. A properly constructed shell should need no additional shielding from fire.

 

Another thing that is not often mentioned, but is common practice, is to paste your spiking string before applying it. There are a couple of ways to do this, such as drawing the string through a fistfull of wheat paste as you wind the string onto your spiking horse, or winding the string up on the horse, then brushing the paste on until it's fully saturated. Either way, you should be spiking the shell with string soaked in paste. When that paste dries, the spiking should shrink a little and adhere to itself and the shell casing, thus adding a bit to the shell's integrity.

 

It looks like you're using pre-made tubes for your shell casings, then cutting "ears" in the ends to make them easier to fold over a disk. An easier and more traditional way is to form the cases from kraft paper. Take a FULL soft drink or beer can (they measure about 2.6" OD), and cut a strip of heavy kraft paper long enough to wrap around it three times. The paper has a grain to it, which means that the fibers run primarily in one direction. Cut the paper so that the grain runs parallel to the short sides of the strip. If you cut it with the grain running the length of the strip, it will be much harder to roll up.

 

Once you've rolled the paper tightly onto the drink can, secure the edge with a bit of glue or gummed tape. This really isn't needed, and you may learn that you prefer to work without it. Now drop a disk onto the can, and pleat the paper down over it. Put another disk on top of the pleats. I like to hold it on with a few pieces of gummed tape. Again, there are some old pictures in my gallery that show the use of casings made this way.

Edited April 24, 2016 by Wiley

[FlaMtnBkr]

Are BP coated rice hulls really that springy and compressible? Rice hulls are almost like a narrower sunflower seed hull. They are very thin and a hard, woody material. By themselves they can flex which makes a bunch of plain rice hulls compressible as the space between them is reduced with pressure. But when coated with BP, that contains a binder and gets rock hard when dry and creates a bunch of little black 'footballs', I guess I didn't think they would give or flex much. But I've only made them a few times as I usually make granulated BP or polverone, and I didn't really try to see if they would compress. They seemed hard and rigid from what I remember of them.

 

Just curious.

[WonderBoy]

Nice shell Aspir.

 

To add to what Wiley said, if you are using an undersized bottom shot, it should be the first thing you load into the shell. Roll your casing, add solid disks, then place your bottom shot, fuse up, in the bottom of the casing and pack around it with sawdust. Then load the rest of the shell contents on top of that.

 

I too prefer pasted string for spiking, but it is not necessary for the shell to function properly. I've not personally ever experienced any shrinking, but it does stiffen up and stick to the shell.

 

It doesn't look like you are using hard hard walled tubes for the breaks, just the bottom shot, which is fine. It does look like you are using thin chipboard. You might try rolling your casing using thick kraft paper (I'm not sure on how you rate paper where you are, but I think it is something like 100gsm or 70lb US) and adding a thin chipboard liner, like Wiley has in some of his photos.

 

And just curious, what did you use to close or fill the ends of your inserts?

 

 

WB

[Wiley]

Right you are, WonderBoy. I couldn't see the seam in the casings until I looked at the video in full screen. Cutting "ears" into the ends of the casing is necessary if using a thicker material like chipboard to form the casings, but if heavy kraft is used, you can simply pleat (fold) the paper down over the disk.

 

Ned has a video of this. Two comments on it though. There's no need to use any glue to hold the pleats down; they stay down just fine without it and glue doesn't add anything to the shell's integrity or break. It just adds time. Another thing is that on small shells, even up to 3", it is possible to fold all the paper down in one go, rather than going around and pleating each turn down individually. Trying to get your fingers in there to pleat down the individual turns can be pretty awful on small shells. I got lots of hangnails, then ultimately started pleated down all the paper at once on all of my shells.

 

Edited April 24, 2016 by Wiley

[Aspirina]

Mumbles, had planned to make a bottom shot with the same size of shell but I thought that might be dangerously for a beginner, but as you say, if it helps the shell integrity, next time I will consider.

Wiley, your answers are very constructive! fire-shield I mean a few discs of cardboard is placed on the bottom of the shell, as I have seen in youtube this "shield" I wanted ask here.

I mean this:

http://oi67.tinypic.com/69gshf.jpg

if you say you do not need then I will focus on making shells the most solid possible and leave aside this idea. I do the casings with toilet paper rolls. I do it because the end result I really like, this cardboard is very hard one after having gone through white glue. I tried them but my kraft paper is not the ideal, and my shells don't look like a strong casing. I prefer to use these cardboard tubes, yet when I get a good kraft, I going to practice for make shells like traditional italian shells

(I liked the idea of ​​the can of beer )

WonderBoy:

 

 

I too prefer pasted string for spiking, but it is not necessary for the shell to function properly. I've not personally ever experienced any shrinking, but it does stiffen up and stick to the shell.

 

I do not quite understand what you want to say. If you refer to apply withe glue before pasting, I'm doing:

http://oi63.tinypic.com/d7ij5.jpg

...

I'm using plaster plugs for inserts, I don't like use bentonite, for my taste it is cleaner

Thanks for the answers guys! Buenas tardes

Edited April 25, 2016 by Aspirina

[Wiley]

Aspirina, there is no need to have any sort of cushion under your shells. That picture shows a pile of corrugated cardboard disks which are supposed to absorb shock from the lift, not protect the shell from fire. Again, a well-made shell will be solid as rock, and there is no need for gimmicky fixes such as that.

 

Just so you know, many shell-building videos on YouTube are full of misinformation that tends to steer beginners wrong. Ned's videos are all excellent, though he tends to use more glue than needed. That's not a problem, just a personal preference. I like to keep things as simple as possible, so I try to avoid unecessary steps.

 

By pasting the string, I meant applying wheat paste to it before spiking the shell. You can do that one of two ways as I said in my third post.

 

Cylinder shell casings are not supposed to be strong by themselves. After all, they're just a few turns of heavy kraft paper with a turn or two of chipboard inside. Pretty flimsy until they're full. Do it right and you'll have a very solid shell. Do it wrong, and you'll have soft spots. If you didn't glue a bunch of stuff, it's not so hard to take such a shell apart and start over.

[memo]

another person that makes good videos is Bangkok pyro. all he makes are cylinder shells. he has many videos. watching his videos or ned gorskis you cant go wrong

 

memo

[Wiley]

Oh, shoot! I completely forgot about Paul's videos! Here's one of him making a 4" casing "upside down". That simply means that the fused disk is installed first. Typically, the fused disk is installed after the casing has been filled with stars and black powder.

 

 

When building a multibreak according to Fulcanelli, you would close the casing with a pair of solid disks, not the fused disk that he uses here. The "upside down" method works well for single breaks, or if you start delving into more complicated multibreak techniques. For now, building them "right side up" is a good starting place. You can easily go up to 3 breaks of color and a report this way.