Aerial Shells

[d4j0n]

That applies to chinese 1/8"?

[justanotherpyro]

It applies to any fuse. As long as your BP isn't crap, a BP prime will help, not hinder the fuse.

[viziers]

Thank you all for your help in this matter, As of last night the remaining 7 shells went off without a hitch I only had two disappointments however.

 

1.the shells I made were with TT and only one seemed to look good when it burst the others were kinda crappy in that they only had a minute tail to them I know it wasnt an ignition problen because I tested them and they lit VERY easily.

 

2. the burst was very unimpressive I mean I taped them with fiberglass reinforced tape vertically a good 5 to 7 layers and following that a few layers of brown adhesive packing tape but the Excalibers had a burst atleast 6 times the aerial spread than my 3" shells and they were at least 6 times louder unless it was because my 3" shells were lacking the initial burst of whistle or flash mix oh wait i forgot I took apart one of the Excals and used the powder in there as a added mix to the shells approx 1 gram per 3" shell.

 

But all in all I was happy that they pretty much did what i had expected guess i need to work on some other types ot pumped stars to see if the results are the same but this time i`m gonna make sure i have proper whistle/flash mix to add to the shells.

[_DB_]

I just finished making my first shell with plastic hemispheres. Here are some pictures -

Two halves ready to go

Together

I then spread a layer of five minute epoxy over the seam. Now I just have to "paste" it using tape until it fits my mortar nicely. It's going to take awhile and it'll probably convince me to get a new mortar that my shells will fit in better. I'll be lauching this shell on the Fourth and plan on filming it. It has Tiger Tail stars in it by the way.

[PyroJoe]

I just fired a 3" can shell tonight. My first actuall canister shell really... It flower potted

 

It could have been because I rolled the case and made the shell from scratch in an hour. Then shot it about 5 hours later. I also did not paste paper on the outside after spiking. Just glued it so it stayed on.

 

Im trying to decide if it was a combination of all that stuff or if my shell construction is faulty.

 

For the can I used about 3 turns of im guessing 70lb recycled construction paper from lowes. For the ends I used 2 end disks each. Folded the paper over one, then glued another on top. My guess is the shell broke at the side walls.

 

Does pasting paper on the outside have that much effect on strengthing the shell? Also, im debating whether to top fuse these shells. I'm just worried that the quick match won't ignite the fuse. Does anyone have experience with top fusing can shells?

 

Im going to make 7 of these tomorrow for the 4th, so I need as many tips as possible!

[Mumbles]

You don't mention this, but did you spike the can? If not, you should. It gives structural integrety to the shells. Some tips as followes:

 

1) Spike the shells. For 3" I used 16 double stranded verticals, and roughly square horizontals. I can't give a number as I don't use a set number. I make different length shells so I just go by eye.

 

2) Use masking tape around the ends of the shells. It will help to seal the corners. I use 2" wide masking tape, around 2 turns around on each end.

 

3) Use lots of glue to seal the time fuse. I mean glue on both sides of the end disk.

 

4) Use a liner. It will give some extra integrety to the shells. Manilla folder, poster board, cardboard beverage boxes, etc will all be suitable. Around 2 turns will work. You can either roll the cans and then put the liner in, or roll them directly in the shell. I personally prefer to roll them directly in the shells. Otherwise you get some voids between the liner and the walls which I don't like.

 

5) After the shells are spiked smear elmers glue over the string. This will give a harder break. It may also harden the walls somewhat.

 

6) Top fuse the shells. This will elimate much of the risk of the hot gases breaching the shell around the fuse.

 

7) Run the leader directly over the timefuse crossmatching. Often times I cut a slit from the leader and place the cross matching directly inside to ensure ignition.

 

8) To harden and add addition structural integrety fill the voids between the stars with pulverone. Pulverone is granulated green mix. It is flamable, and will make a very solid shell for better breaks.

 

9) Glue the first folding of paper directly to the first end disk. It is unclear or not if you do this. This is your last line of defense from the lift pressure and gases, definatly glue it to make a good seal.

 

10) You don't need to glue on the outer paste wrap. I have before and I really can't tell the difference. I do use an outer wrap, You can either tape or glue it shut, but I do not paste it on. I just roll a few turns of light weight paper, tape or glue it so it doesn't unravel, and tie the ends shut.

 

This may have gone beyond what is needed for you, but I wanted to be able to help as many people as possible with this.

[_DB_]

It's also a good ideal to allow time for the glue to completely dry. I always allow 24 hours for my glue to dry on completed devices. That is, when using something like white or wood glue.

[bubbelpower]

How do i get a really good break on my shells? Or rather a good spread, because my shells boom very loud, but the stars do not spread very far at all.

 

I have this problem mostly on my 2" shells and bigger.

 

I use only BP for break, so i figured that that is the problem. But is it really it?

I paste them very well. My 2" shells are pasted with 6-7 layeres of kraft. Could spiking them help for a better spread?

The break/spread is symmetrical, so there is no problem with that. It is just that the stars move so slow out of the braek.

[justanotherpyro]

If the stars are really light then they won't fly very fast. It doesn't matter how much BP you used to shoot a feather, it would only go so fast. I've only had this problem with a few small stars like cut TT.

 

If your capable add some whistle ( take it out of a piccolo peet if you have to ), or flash and see how it affects it.

[bubbelpower]

They are rolled stars, not cut.

 

And when i shoot them out of my stargun, they go lika maybe 40 ft high, so they are not "feather-light".

 

 

Yea, that with whistle sounds like a good idea, i have about 5 dozens of those mini-whistle rockets.

 

 

And BTW, if i have to light stars, how do i make them more dense?

[PyroJoe]

You can't really make the stars more dense after you have completed them, but for future reference. If you are rolling them, keep them pretty wet the entire time of rolling and it will help.

 

Thanks for the tips Mumbles, yes I did spike the shell btw. Im going to do a lot more horizontal spikes on the next shells to increase the wall integrity. I will also top fuse the rest to insure that it is not a gas leak issue. I do have a liner inside the can that I rolled and placed in afterwards, its about the weight of a cereal box. I think for the rest of the cans, after I load them all im going to roll another 3-4 turns of paper on the outside of the can before spiking it.

 

Hopefully they work out for the 4th, since I can't test anything now! Wow I hate procrastinating.

 

P.S. I filled the canule with BP coated rice hulls. Will these give a very good break? Could it have also played a roll when the shell flower potted, due to compression of the canule or something?

[PyroJoe]

Here is a video of my failed shell. The colors were awesome! I used my 8mm cam instead of my dads new digital and I think it captures color much better. The stars finishing last were silver streamers and the rest were green.

 

http://www.apcforum.net/files/3inch_flowerpot.wmv

 

It was a cool mine anyway!

[justanotherpyro]

After having a 2" shell flowerpot on me ( last one out of 14 ) I thought of an interesting effect for a shell. Purposely timing a shell to go off way before apogee so that the stars travel in the mine type fashion but a good distance up in the air. It would look great with a 4" that was 50 feet off the ground with a weak burst. They would probably be more dangerous than a shell or mine though because of the shell going off close to the ground.

[Mumbles]

What you are describing is known as a waterfall shell. Well, they are designed to go up, and then start back down like a waterfall. A weak burst is used, leting the upward momentum do most of the work.

 

Spider shells are done in a similar manner, but with a hard burst. The "legs" travel out and up, and then back down. This is done closer to the apogee. I think generally the rule of thumb is to time in 25% less for spider shells.

[justanotherpyro]

I didn't figure I had come up with anything new, but now the proper names are out. They must be long burning stars in those types of shells.

[_DB_]

I launched my 3 incher tonight.

 

3 inch Tiger Tail shell

 

I'm glad that it worked properly, but man was that break ugly! I guess that's what you get when you slopply "paste" a shell with tape. I just need to break down and get a proper 3 inch mortar. I will soon. I think the shell could have used a little bit more flash too. I only used a gram but a lot got scraped away when I was pulling away the post card in between the two hemispheres. I didn't trust myself with just swiftly snapping it together. Oh well. My breaks should get better with practice.

[d4j0n]

So what is the difference between using a flash booster and a whistle booster? Does using whistle have any kind of advantage?

 

On a side note, while watching the commercial displays around my area, I found a number of strangely shaped breaks. I saw wireframe CUBE breaks!!! Just curious, how does that work?

[Mumbles]

Well, whistle doesn't produce as much light as flash does. It is better to some for charcoal stars where the bright flash could take away from the effect.

 

With the cube I have an idea actually. It could be a 2-D cube layed out in the shell like they do with rings, elephants, letters, etc. You know how to draw a cube on paper that looks 3-d. that could be how. Either that or they actually make a cube in the shell.

[_DB_]

I also saw some of those cube shells, must be a popular thing this year. They look pretty cool unlike those smiley shells that just annoy me for some reason.

[d4j0n]

I think it's because smiley shells just look kinda corny. I couldn't do a good one, but they still look corny. Apparently in asia they have chinese character break shells as well.

 

I also saw a bunch of shells where the stars are in the range of where they should be after a break, but traveling in a random direction instead of away from the center of the break...kind of hard to explain. Are those go-getter star comps?

[anthropoid]

Would you guys mind sharing your pasting techniques and maybe give some tips in general about pasting? I've just pasted 12 3"-4" shells in a row and it took me over half a day just to paste them (!!), they don't look really symmetrical or neat and smooth as most of the shells I saw you guys making and although the break itself is very nice it's still not perfectly round...I just feel like my pasting method sucks and I'm missing something

 

I'm using 50 lb Kraft paper (can't get any other weight) cut into strips and soaked in wheat paste, 16 strips per layer, each pasted on half of the previous so every layer is actually 2 layers, 6 double layers for the 3" and 7 double layers for the 4"...It takes about 5-10 minutes for every layer - and that is really time consuming and the final product isn't even perfectly round Anything wrong with my method? actually that's the only one I wasable to find so I'm not familiar with any other pasting techniques

[bubbelpower]

I can't see what you are doing wrong. I also use 50 lb Kraft, and I paste my 3" 5 double layers, but it takes only 10-15 min for the whole pasting, and i always get it almost perfectly round.

[Mumbles]

Well, there are two important questions here that would possibly be the culprit. What are you using as the adhesive? Are you breaking in your paper?

 

I would recomend wheat paste(commonly sold as wallpaper paste) for the adhesive. It is the standard of sorts.

 

Breaking in is a process where you let the paper completely become saturated with water, and in this case the glue as well. If you've ever gotten a piece of paper wet, you will notice it just gets wet. However if you let the water sit for an extended period of time you will notice it begins to become somewhat transparent and lose it's structural integrity. This is what we are shooting for. If you're not doing this, you're not going to be able to lay the paper down as flat, and thus not as round or smooth.

 

For shells of those size I would recomend 30lb though. It will produce a much cleaner result. It is commonly sold in the form of paper lunch bags.

 

Please describe the pasting pattern you are using as well. There are some that produce better results than others.

[anthropoid]

Thank you both for your replies =)

 

Mumbles - I'm using home made wheat paste as the adhesive and it worked very well so far in everything else so I think that my glue isn't the problem

 

I didn't know about the breaking in process, that's probably the reason why my shells aren't perfectly smooth - so far I was only laying wheat paste on the strips with a brush on both sides to get it really wet and then pasting them

 

I can’t get any other Kraft paper - here in Israel it's extremely hard to get Kraft paper of any weight, even in the form of simple lunch bags - I'm just really lucky because there is a factory that works with all types of paper in my city and from time to time they throw leftovers, among which I’m usually able to find strips of 6 foot wide and dozens of foot long 50 lb Kraft paper

 

Hmm, I don't think I really understood what you meant when you said "pasting pattern" (my English isn't perfect, it's actually quite far from that ) so pardon me if I'll be off track with the reply – I'm cutting 16 strips for every "double layer", painting each strip with wheat paste on both sides and then pasting it from the lowest part of the shell (the fuse) to the highest part(wasn't really sure how to explain that)...The next strip is pasted so it covers half of the previous one and so on until I paste all 16 strips and complete a full circle around the shell (and have one finished "double layer"..), then I just repeat this process as many times as I need, depending on the size of the shell...Hope that covers what you meant

[ravaz]

Would you guys mind sharing your pasting techniques and maybe give some tips in general about pasting?  I've just pasted 12 3"-4" shells in a row and it took me over half a day just to paste them (!!), they don't look really symmetrical or neat and smooth as most of the shells I saw you guys making and although the break itself is very nice it's still not perfectly round...I just feel like my pasting method sucks and I'm missing something

 

I'm using 50 lb Kraft paper (can't get any other weight) cut into strips and soaked in wheat paste, 16 strips per layer, each pasted on half of the previous so every layer is actually 2 layers, 6 double layers for the 3" and 7 double layers for the 4"...It takes about 5-10 minutes for every layer - and that is really time consuming and the final product isn't even perfectly round Anything wrong with my method? actually that's the only one I wasable to find so I'm not familiar with any other pasting techniques 

Do you smooth down the pasted paper at all? Depending how many layers I'm pasting in, for smaller shells usually about halfway through pasting, I'll burnish it by rolling the shell on a flat surface such as my work bench, then again at the end so the paper lays down and aheres better. Without doing this, the shell looks like shit and probably won't perform as well.