Improving my shells

[Aspirina]

Hi all!

here are some of my aerial shells that have been improving, thanks to the users of this forum. I have applied some of the tips:

- I changed the type of cardboard used for tops

- better black powder with more time milling with a more big granulation

- smaller "lift cup"

- I did not make more stars, but I cut them for get a burn all at once

It is the first of 3" that works well

https://www.youtube.com/watch?v=LXAS_M6nreY

I hope you like it! I accept any kind of constructive criticism

[Mumbles]

Are you pasting the shells at all?

[braddsn]

Your shells are improving! I don't build cylinder shells, so it is hard for me to give advice on construction. I would say Wiley and Mumbles will be able to give you some solid build advice.

[Wiley]

I liked that last 3! Also, your blue is absolutely fabulous. Keep making it; it's amazing.

 

Like Mumbles asked, are you pasting your shells in?

 

I noticed that you're using one strand of string for spiking. I think you'll find that using two or even three strands of smaller string, well-pasted, will snap more consistently than a single strand. All string has weaker spots. Using multiple strands can help even out these variations in strength.

 

I'd personally roll my casings from kraft, but yours seem to be working well. Keep up the good work!

[Aspirina]

I pasted my shells with crumpled din a4 and I put a lot of white glue. Sorry for not having more photos. I have to change my camera... Next time I will string two times my shells. You are right, my string is very thin.

 

greetings

[dynomike1]

I usually don't do stares in canisters, i do inserts in mine. How many turns of paper did you use, and what kind ? It might help to find Paul's Molders video and watch it, every time i watch them i see something i missed of forgot. The last one would have been a damn good palm if it had a comet on it. The glitter didn't look like glitter to me , you might want to change your formula.

[Aspirina]

I said before, I use din a4 normal white paper. The number of laps I give is not always the same, I do all I can till the shell comes a little tight in the mortar with the outer paper counting and quickmatch. I Use a lot of white glue, usually with drying a day and is like a stone, here a pic:

http://oi65.tinypic.com/21kxo61.jpg

Respect to d1 glitter, I totally agree, someone knows a way to optimize the formula? what is the best process? and it is true, the third had become better with a comet!

greetings

[schroedinger]

Aspirina, do you use A4 copy paper even for the inner casing?

 

To work out all flaws it would be really awesome if you can take and post pictures that show your building process and materials. The black powder you use, can you make a baseball test?

[dynomike1]

I went back and watched these shells again, i may be wrong but what i saw was one of two things on the first two. The best i could tell It looked like either they blew out the ends or all the stars did not light.

[lloyd]

I think they 'squirted', because the burst powder was pretty slow and a bit sparky -- again, that indicates that it is not milled sufficiently.

 

Aspirina, you'd do well to duplicate the "baseball test" with your powder, before committing it to shells.

 

If pressure does not build up quickly enough inside a shell, it will usually rupture unsymmetrically.

 

LLoyd

[Aspirina]

First of all, thank you for your answers

I will upload in this post my process photo by photo, it is true that I have perhaps been little information. See I'm talking to people who play to another level... you guessed right in saying the black powder in burst is slower, I used two different types of powder (sorry for not mentioning earlier) the lift powder on the video and then for burst charge other b.p of poor quality coal, much slower. I'm sure that's why (as it says lloyd) by which my case (especially blue) did not break symmetrically.

I can not understand what you mean dynomike1 sry. I'm a little bad for languages ​​and the education system of this country stinks...

I will perform the baseball test when I make more black powder, I spend what I have left in the new shell I'm doing now.

Un saludo

Edited March 1, 2016 by Aspirina

[schroedinger]

Yes tnat was a fault, the canule must be filled with only high quality b.p. or if you have a big center MCRH of good quality.

[Aspirina]

Here the procedure that I follow to make my shells. I have to say this shell specifically failed ...

but this It is the exact procedure I follow to make my shells. It would very grateful if someone tell

me the things I'm doing wrong, I think the failure of this was to use a poor quality cardboard for

tops, popcorn carton box hahahaha. Later I will share the video of the fail and a "baseball test" of my b.p

 

PD: I try to turn the images but is not saved

thanks

Edited March 3, 2016 by Aspirina

[BlueComet24]

What type of aluminum did you use in your glitter? I've made N1 (similar to D1) with Alcoa 120 and it is beautiful and distinctly a glitter.

 

Y Aspirina, su inglés es mejor que mi español. Es bien.

[schroedinger]

The process doesn't look to bad, but your materials don't look good at all. It didn't only fail because of the end disks.

 

Ok, you started with a inner layer of corrugated carboard that looks like cereal box. This isn't needed. Use a liner out of manilla or poster board.

 

Then we have the casing. You used a very heavy corrugated paper (recycled multiple times). Here use 70 - 100 gsm virgin kraft. The paper used is propably the main reason for the shell to fail.

 

Next we have the string. Looks like .5 -.75 mm jute twine. You need two strands of 1 mm flax, hemp or cotton twine.

 

For the enddiscs you can use old books, just look around often they can be gotten for free.

 

If you can't get other materials, look into maltese shell construction.

[Wiley]

Aspririna, you can take a look at the stuff I have in my gallery if you like: http://www.amateurpyro.com/forums/gallery/member/12911-wiley/ .

 

I used ~70lb paper from the hardware store to roll those casings, and the liner material is manila folder. The white end disks are punched from a material I got at Staples called white illustration board. I'm sure you can find something similar locally. The thicker disks are punched from 1/8" chipboard. The string I used is two strands of 20# hemp twine used for beading. I'm currently using three strands of #3 crochet thread, and I'm liking the way it lays down flatter. Shells are fireproofed either with 3" wide gummed tape, or with pasted paper.

 

Keep in mind that these are 1.75" shells. Any bigger than that and I'd use the hemp twine.

 

Oh, and there's absolutely no reason to snip the overhanging paper into little ears. Just pleat it down. This will be easier if some better paper is used. Ned shows how to pleat the paper down, but he uses a lot of glue that also isn't needed. Just pleat the paper and beat the folds into shape with some solid object like a dowel. The disk you put over top of the pleats holds them in place.

 

Edited March 6, 2016 by Wiley

[Aspirina]

 

 

What type of aluminum did you use in your glitter? I've made N1 (similar to D1) with Alcoa 120 and it is beautiful and distinctly a glitter.

 

Y Aspirina, su inglés es mejor que mi español. Es bien.

This is the aluminum I use. I dont know If this is the ideal for this use but my d1 glitter dont work like d1 glitter....

Gracias BlueComet24, su español también suena coherente!

http://oi63.tinypic.com/x3z6es.jpg

Wiley and schroedinger , thanks for the tips , this week I will go in search of material I hope to find something interesting. I think that's the main fault. Wiley your shells are a true craftsmanship... how long it takes to finish a multi break ?

here you have the video of the fault. might please you have something more to say hahahaha

https://youtu.be/uECpXH70Vgo

Edited March 6, 2016 by Aspirina

[BlueComet24]

That's flash powder aluminum. It is very reactive and burns very quickly, so it's great for reports, boosters, etc., but is the wrong type for glitter stars. Save that stuff for other uses and look for aluminum that is 120-325 mesh and spherical for glitter compositions. I use Alcoa 120 and can say that it produces beautiful sparks. The spherical aluminum has a lower ratio of surface area to volume and is less reactive than flake aluminum, which is what you have. Flake aluminum catches fire quite easily, much like the thin edges of a piece of paper, while spherical aluminum is more like a log and takes a bit more to get going. Here's a page that has some good information on different types of aluminum: http://pyrodata.com/chemicals/Aluminium

[schroedinger]

Aspirina thats flash aluminium.

The Al you want is available as 100 micron aluminium of paint and car shops. Look for Al that states to be added to epoxy. Else you can use pyrogare 325 mesh atomized Al.

[Aspirina]

all right! I know where to get that aluminum. Thank you for answering so quickly. I knew I did something wrong