Urgent question !

[Miech]

I'm using CMC the whole time, so little chance that is the problem. I rather think you should cut down on pasting, I use eight layers on a 3" shell and have pretty nice breaks every time.

[50AE]

I'm gonna cry! The purple chlorate shell had a single star lit ! The break was much less louder. These are my worst moments in pyro, oh God !

[dagabu]

I'm gonna cry! The purple chlorate shell had a single star lit ! The break was much less louder. These are my worst moments in pyro, oh God !

 

Shell Size No. Turns / Paper Weight Length of Sheet

 

3" 3 turns / 30-40 lb. 1 - 24" sheet

 

4" 4 turns / 50-70 lb. 2 - 24" sheets

 

5" 5 turns / 60-70 lb. 3 - 24" sheets

 

6" 6 turns / 60-70 lb. 4 - 24" sheets

 

8" 8 turns / 70 lb. 4 - 48" sheets

 

 

 

 

If you need to make up diameter with pasting, spike loosely with cotton string between each layer, use 5-8 grams of slow flash or whistle in the canuule to add to the break but no more.

 

 

 

 

D

[JamesH]

I feel your pain 50AE!! I know exactly how you feel!

I made a few ground tests of 2" round shells and fired them earlier.

They were made the same as before, same stars, with 4:1 bp on grass seed with 0.4g of nitrate flash. I only changed the way they were pasted.

The first one was wrapped tightly with flax twine and 4 layers of masking tape - I got a decent bang, but no stars lit - what a supprise!!

The next had only 4 layers of masking tape - less bang and only 2 stars lit, and they weren't thrown very far or very forcefully.

The next had 2 layers of masking tape - not much different to the above.

I made another with 2 layers of masking tape and half the amount of flash, 0.2g - very weak burst with only 3 to 5 stars igniting!

Following the firings I found a lot of unignited stars laying about, since when are bp based D1 glitter stars hard to ignite?? They work just fine fired from a mine!

 

So, the changes I made didn't make much difference to the result. A couple of stars igniting out of about 85 is terrible! What next?

 

50AE what are the construction details of your latest purple chlorate shell?

What type of hemispheres and kraft paper are you using, and what method are you using to paste them?

[Mumbles]

You guys are primng your stars well, right? To get good hard breaks, you need good hard bursts which require good priming.

[firetech]

You guys are talking about layers of pasting, but thats not really an issue if you don't state what # it is. If you are using 60# kraft you do not need nearly enough layers as if you are using 35#. If your stars a blowing blind prime them heavily and/or decrease the pasting. If your breaks aren't hard enough add some booster and/or increase the layers. I don't know why this isn't so easy for some of you but it's pretty simple to me.

[50AE]

Ok look. Later I fired a shell with emerald green stars, they were primed and everything lit fine. The break was symmetrical, but small though. But why the purple did not, it was chlorate based ? The layers were the same number (60lbs kraft, 7 layers, 3 strip method).

Do chlorate stars need a prime ? They light quite easily.

I also made the chlorate stars 30 hours before putting them in the shell, but they were really hard as a rock and the inside surface was very hard when scratching with my nail. They were quite easy to ignite.

 

Edit : I wonder if the thickness of the paper plays a role? My first 3 shells worked great, pasted with 14 layers of 35lb craft and unprimed stars.

Edited December 29, 2009 by 50AE

[JamesH]

50AE, if the purple and green shells were identical in every way, and the only difference between them was that the green ones were primed, it does sound more and more that it could be a priming issue. Try priming all stars with the prime you used on the emerald green stars to see if it makes any difference.

What kind of stars are you using, round, pumped or cut?

Do all your stars ignite when fired from a star gun or a mine?

 

here are a few videos of my latest failed attempts:-

http://s11.photobucket.com/albums/a152/jam...pasteLayers.flv

http://s11.photobucket.com/albums/a152/jam...pasteLayers.flv

 

But, here are the very same stars fired from a 7/8" mine:-

http://s11.photobucket.com/albums/a152/jam...terStarTest.flv

 

Why are they igniting in a mine but not in the shells? Could it be that they are in contact with the flame for a longer period of time in a mine?

[50AE]

The shells were made identically.

I'm using cut stars.

I can't prime the stars no more, they're in the shells. I can only pray for them to break good.

There's no more time to make new stars. I'm assembling 2 more shells with stars that I have tonight.

[firetech]

The thickness of the paper makes a huge difference. 7 layers of 60# and 7 layers of 35# are not the same. Try 4 layers or so if you're going to use 60#, maybe even less. Especially if you're using wheat paste which dries like a rock.

 

Another tip: Prime every star. It's so simple and it's very cheap insurance. If you have space in your shells to do so, roll the stars a bit with tigertail, and then bp. This will allow your stars to slow down a bit before the color ignites and will prevent them from blowing blind.

[50AE]

No firetech, I ment if for example 14 layers of 30lb paper is the same sa 7 layers of 60 lb paper.

[Mumbles]

Yes, of course you should prime chlorate stars. You're trying to get big hard breaks, you're going to need a good prime. Even chlorate stars are liable to blow out at high speeds. The Japanese roll a layer of willow or other slow burning composition on the outside of all of their stars. You will probably notice how they "blink" on, this is why. It blends in with the first layer of the outer petal which is usually a charcoal streamer or glitter of some sort. I think I am going to start putting a layer of spider star mix on the outside of all of mine. That has to light, right?

 

For what it is worth I use 7 layers of 35# paper tape on my 3" shells, and still occasionally over break them. 60 or 70# really isn't fit for small shells. You have to put on so few layers, it is easy to have weak and strong spots, where as larger shells even out over time. It doesn't lay down as well.

 

It really is too late for this now, but you should try to dial in your breaks somewhat before the last minute.

[50AE]

That's what I needed to know ! Thanks Mumbles ! You returned back my hapiness.

It's too late, but I now I know.

 

If I remove the thick paper layers (unpaste the shell) somehow and I repaste them with 35lbs paper, would they improve ?

Edited December 29, 2009 by 50AE

[Mumbles]

Removing some of the layer might help. Well, you can't light any less stars

[50AE]

But the break isn't loud and big using this paper, even with 7 layers of it.

I think I will try to remove most of it and repaste the shells with the 35 lb paper. I remember my first 3 shells were pasted with it and they all worked fine without a star prime. The problems started when I switched to the 60lbs kraft.

[dagabu]

But the break isn't loud and big using this paper, even with 7 layers of it.

I think I will try to remove most of it and repaste the shells with the 35 lb paper. I remember my first 3 shells were pasted with it and they all worked fine without a star prime. The problems started when I switched to the 60lbs kraft.

 

I think I posted this elsewhere but I prime everything including BP!

 

D

[psyco_1322]

You prime your black powder? Silly.

 

So I would guess that your prime sucks, and in the soft mine the stars take the fire, but your hard breaking shells wont light them reliably. Small shells are touchy, I always recommend to noobies to start out with 3" shells, nothing smaller, if they want to go smaller, do it later on.

[firetech]

If its not loud, then it's possible you're over pasting them. I don't know why or how but an over pasted shell may not produce as loud of a bang. That is, of course, based on my own personal experience. You also need a booster to create that bang. In small shells its just necessary. Until you're up in the 6" range you pretty much need some booster. After that you can use straight hot bp on hulls, according to Shimizu...

[Mumbles]

You never NEED a booster. It is just a short cut for people who don't want to do any extra pasting or tweaking, and want to replicate the over-broken chinese shells on the market.

[50AE]

Ok, I've done something I think some of you have never done, unpasting your pasted shells.

 

During the night, I dissected my 2 chlorate star shells, I took the stars out and primed them with meal. Then, I let them dry with the fan.

Later, I had made a 300g batch of very hot pulverone, I put it in front of the fan as well.

 

Now in the morning, I have dry stars (checked 3 of them for ignition, breaking and inside scratching). The pulverone also seems dry and it's fast, but I'm putting it at preheated and turned off oven at 60C to dry it completely. Previously, I've put it in a drying container containing CaCl, but I want to be completely sure everything's dry.

 

When the shells will be assembled, I'll be pasting them with 12-13 layers of 30lbs paper, like I've done before successfully. A friend will be helping me and a second fan will blow more air.

 

There is only one shell with unprimed stars, W11 glitter. But there's no time now. I hope it works alright.

 

I really think I'm doing things correctly now ! If something goes wrong this time, I could really quit making shells.

 

I have another issue, but it's not fatal. Because I've rammed the same length of black powder in thinner tubes, my spolettes have a 1-1.5sec more delay. The shells reach the top, when after 1 sec falling they burst. Could be something done, like taking some black powder from the spolette and filling it with pulverone ?

Edited December 30, 2009 by 50AE

[swervedriver]

be careful if you decide to scrape out/drill back the spollette in a ready-to-fire shell...

 

one thing about bp prime I've learned the hard way is "slow is good", a heavyish layer of hand mixed green meal over a 10% Si or dark Al in one of the KP/red gum primes. I prime everything man, even charcoal stars. It's just a small extra step among the 50 other tedious steps of making a shell, so why not?

 

You never NEED a booster. It is just a short cut for people who don't want to do any extra pasting or tweaking, and want to replicate the over-broken chinese shells on the market.

 

What's up mumbles , what's wrong with huge over-broken-and-sparse chinese style breaks? I like to use booster. Besides, a billion screaming chinamen can't be wrong, lol. One of these days you'll post a video of your nice round unboosted 3" black powder break for us to awe. (I would enjoy seeing one of your shells)

[50AE]

I think I won't touch the spolettes. I think I could break the strength of the black powder inside that way and make it weak, which could lead to a flowerpot.

 

There are 8 layers of 30lb paper now. I'm pasting a last one to make it 10 layers and I'm done.

[dagabu]

I think I won't touch the spolettes. I think I could break the strength of the black powder inside that way and make it weak, which could lead to a flowerpot.

 

There are 8 layers of 30lb paper now. I'm pasting a last one to make it 10 layers and I'm done.

 

OK, this may be a stupid question but here it goes:

 

If you have to paste so many layers, why not just use a larger case former in the first place? 3-4 turns of 35# kraft is enough to make for good break with a spiked canister.

 

D

[Mumbles]

Unless I completely missed the boat here, he's making ball shells.

[dagabu]

Unless I completely missed the boat here, he's making ball shells.

 

Well there you go! Thanks for answering, still don't like that many layers.

 

D