What is the best (and safest) way to get a good break?

[OblivionFall]

But the big thing you can try is a trick to increase burst strength. Since you don't want to use flash, but have made it, I assume you have some dark aluminum on hand. You can take your BP burst and give it a light dusting of aluminum. Put the BP in a bag with around 3-4% aluminum and shake it up to coat the granules. The type of aluminum will change the amount that will stick but you just want a light coat and don't want to add so much that it doesn't stick and there is extra in the bottom that isn't sticking. It won't hurt to do so but is wasteful and you don't need that much.

 

Since there is no oxidizer mixed in the aluminum it is not sensitive like flash. But when the BP burns the aluminum also burns which really increases the burning temperature which increases pressure and greatly speeds up the burn rate of the BP which increases the burst strength.

 

It can actually make a shell sound like it's loaded with flash and almost sound like a salute if you use good BP, a dark small micron aluminum, and good confinement. So be aware that you might be making more noise as well. It will also increase the light output of the break which some people don't like but if you only use a small amount it shouldn't be as much light as a healthy boost of flash. At least it doesn't look as bright to me but I haven't tried them side by side. If you try it let us know what you think.

That's actually a really good idea! I will definitely try that! Looking forward to making shells now.

 

What percent of aluminum powder would you recommend? I saw a youtube video on it just now that said 1:5 Al:Black Powder was best but it could definitely be inaccurate.

 

I'll do some tests. If it ends up that a 15g BP + Al salute is about just as loud as a 10g KNO3:Al:S flash salute I'll 100% go with the BP and Al combination.

[FlaMtnBkr]

Honestly, I've never measured. I just add a pinch until everything is well coated but not enough that it starts to collect in the bottom. It's not very much and I assumed it was less than 5% using German Black and if you plan on measuring it, would start with the 3-4% I mentioned and adjust from there if you need to. 1:5 would be 16.6% aluminum and a lot more than what I thought I was using but I suppose it could be higher. Still think I would initially try what I mentioned above.

 

I'm surprised you found something on YouTube about it. I've mentioned it to quite a few people over the years but have never heard of anyone else discussing it or even replying to me on the forum what they thought if anyone tried it. It always seemed to go overlooked from what I could tell but is a handy little piece of info.

[Seymour]

I'm probably not adding much to the conversation, but I feel like trying to contribute

 

I would also suggest just trying a small amount of Aluminium. What FlaMtnBkr says is on point. I've only done this with dark flake Aluminium, and it may work with bright flake, but I doubt any of the other grades used in pyrotechnics would be effective.

 

Also what has been said about pasting in the string is I think critical. I've always added the paste after I've spiked the shell, but perhaps that's not the best way and just be what I do because I'm more of a ball shell guy...

 

I am also all for using roughly grained BP (wetted with a binder and granulated, not pressed and granulated) to burst canister shells, and small ball shells.... and ball shells up to 12". While coating rice hulls and similar can work very well to reduce the quantity of BP used, I tend to throw economy out the window and try to pack as much pyro in to the space I have.

 

From what I can see of your shell building skills (they seem good to me) and the tips you have already got, if aluminium boosted black powder grain in your improved spiked, pasted and papered still leaves you desiring more power, I would suggest trying to make even hotter BP or bite the bullet and using flash.

[Andres1511]

That shell really looked nice ! Good job, keep it up .

[OblivionFall]

Honestly, I've never measured. I just add a pinch until everything is well coated but not enough that it starts to collect in the bottom. It's not very much and I assumed it was less than 5% using German Black and if you plan on measuring it, would start with the 3-4% I mentioned and adjust from there if you need to. 1:5 would be 16.6% aluminum and a lot more than what I thought I was using but I suppose it could be higher. Still think I would initially try what I mentioned above.

 

I'm surprised you found something on YouTube about it. I've mentioned it to quite a few people over the years but have never heard of anyone else discussing it or even replying to me on the forum what they thought if anyone tried it. It always seemed to go overlooked from what I could tell but is a handy little piece of info.

I can remember seeing an experiment that a pyro did. He made something like 100 firecrackers exactly the same way each time with an electronic ignitor. In 20 of them he had BP, 20 of them he had BP with something like 5% Al, then 10% Al, then 15% Al, 20% and finally KClO4:Al. In the end (from what I can remember) the firecracker that had BP and about 20% Al was a little under 50% as powerful as KClO4:Al. This means that BP with 20% Al is potentially as powerful as KNO3:Al:S which I believe is about half as powerful as KClO4:Al.

 

So I think that I will go with BP + 10% Al. If I'm not happy with the break I will add more or less. 20% is a pretty absurd amount I would say. So 10% sounds good.

[Ubehage]

I can remember seeing an experiment that a pyro did. He made something like 100 firecrackers exactly the same way each time with an electronic ignitor. In 20 of them he had BP, 20 of them he had BP with something like 5% Al, then 10% Al, then 15% Al, 20% and finally KClO4:Al. In the end (from what I can remember) the firecracker that had BP and about 20% Al was a little under 50% as powerful as KClO4:Al. This means that BP with 20% Al is potentially as powerful as KNO3:Al:S which I believe is about half as powerful as KClO4:Al.

 

So I think that I will go with BP + 10% Al. If I'm not happy with the break I will add more or less. 20% is a pretty absurd amount I would say. So 10% sounds good.

From my experience, you can use granulated BP with 10% Al. I don't wet my BP with Al, so I just hand-mix it after granulation.

 

If you fill your container about 3/4 with this, it will make a good solid boom. Even without proper confinement.

Edited December 4, 2015 by Ubehage

[OblivionFall]

From my experience, you can use granulated BP with 10% Al. I don't wet my BP with Al, so I just hand-mix it after granulation.

 

If you fill your container about 3/4 with this, it will make a good solid boom. Even without proper confinement.

Ok yeah sounds good. I'll do some testing over christmas break. Adding enough confinement is no big deal at all. Nothing I can't do.

[Stef727]

So here is another shell I made

 

Break was perfect (atleast for my )

 

For the shell case I used 4 turns of craft paper, it was probably 30 or 40 pound paper, don't really know sorry.

The burst charge were BP rice hulls and around 3.5g of kno3 flash in a flash bag.

The pasting was 2 layers of craft paper.

 

The shell weight 260g and I used 35g lift (I'm going to use 28g or so next time, should do it)

 

 

The only thing I should probably inpprove is to make the stars size more even, some burned out sooner than others.

Edited December 18, 2015 by Stef727

[lloyd]

Nice break!

 

L

[dynomike1]

Looks good. I have got to try sunrise yellow.

[Stef727]

Looks good. I have got to try sunrise yellow.

 

Ye sunrise yellow is a really nice star, it's easy to make, bright and a nice color, the only problem is that it absorbs moisture from air and makes a lot of smoke, that's why I guess it isn't used much in pro pyro....

 

Btw in the video the stars look a lot more yellow than what they really were.

Edited December 18, 2015 by Stef727