How to test Stars?

[peterpyro]

Hey this is my first post on this forum so take it easy 😀

 

I am just beginning to get into pyrotechnics, and made my very first TT stars, i dont know if they even work and I dont know how to test them would I put them in a CB tube and light it?

 

Any help is much appreciated thanks!

[Mumbles]

Welcome. The first thing is that you'll want to make sure they're entirely dry. Tigertail can be slow to let all the water fully evaporate. Depending on the size and local temperature/humidity/airflow/etc. they can take upwards of week to weeks to totally dry out. I'd give them 3-4 days to a week at minimum.

 

Testing them isn't all that difficult. You can light them on the ground as a first test. They will burn, spray some sparks around, but probably leave a glowing ember on the surface. High charcoal stars generally rely on flying through the air for the true effect and full combustion. A small device known as a star mine is probably the best way to test. It's sort of what you described. Some granular black powder on the bottom, and some tiger tail stars over the top. When the black powder ignites, it should fire the stars up in the air and give a nice column of charcoal streamers.

 

You haven't mentioned anything, but if you have not worked on it, being able to make functional black powder is key to almost everything. It can be purchased as well, but many pyros tend to make it due to significantly lower costs.

 

Also, I moved this to a different sub-forum. Rocketry doesn't quite cover it.

[peterpyro]

Ive made BP, but how would you granulate it?

[peterpyro]

Also its been 2-3days since I made them, and when I drop them from 3 inches into a piece of wood the make a nice klunk that makes me think theyre dry

[Richtee]

Ive made BP, but how would you granulate it?

 

Have a look thru the basics posts here. Best way is to “corn” it. But it can be “riced”... never as fast as pressed/corned powder tho.

 

[peterpyro]

Thanks Ritchee and Mumbles, Ill try that 😀

Here is a diagram I found on cannonfuse.com

 

https://cannonfuse.com/images/content/1578421033463.png

Edited April 27, 2020 by peterpyro

[Richtee]

Yep... AKA a “star gun” Just need a few grams of powder. By using very LITTLE powder you can kinda get an idea of how well your stars will ignite also. Keep a bucket of water handy in dry areas. Keep in mind also how long they burn, because in a shell you will want to lift them quite a bit higher than that

[Mumbles]

To granulate BP, you generally want to wet it with something, and press it through a screen. The most common thing to wet it with is water, generally with 2-5% dextrin added to the BP to make it even harder. Some people have reported success using 70% isopropyl alcohol and no additional binder. I have however heard some varied results on this, and it may perhaps have to do with the charcoal source. That whole topic is very subjective at the moment in my opinion, and no one has a real answer as of yet. Either is probably fine to get started with. Water and dextrin will definitely work. Alcohol may or may not give as durable grains as you want, but for this project it wont matter all that much.

 

For a screen, ideally you want something a little coarser than a window screen (16 mesh). If that's all you can get, it will work though. If you can, try to seek out something around 12 mesh. Mesh is holes per linear inch. Some kitchen strainers are about right. You may read about black powder grades ( A window screen will probably give you something in the 4-5FA or 2-3Fg range. A 12 mesh will get you something around 3-4FA or 1-2Fg. Either are totally fine for smaller items. If you move into larger devices, it would be wise to invest in something even coarser. Larger BP granules burn a little slower and are more gentle, which is required as things get bigger.

 

As for testing your stars, there may be a couple of ways. If you happen to have a warm sunny day, you can toss a handful in a plastic bag and place it in the sun for a little while. If they're still wet, you should see condensation start forming inside the bag. The other way is to cut one star in half. You'll be able to tell if it's dry to the core by looking at it most likely. Any wet spots will be noticeably blacker. Alternatively, you can scrape the inside with your fingernail or some handy piece of metal. If it's dry it will give a white-ish streak all the way across. Anything still wet will crumble or maybe smear, or just wont give as dark of a streak.

 

That diagram is just about right. I personally like to separate the lift from the stars. A second paper wad is enough. Keep in mind RichTee's advice about keeping some water handy. Tiger tail can leave a lot of burning embers and sparks. The paper wads as well can smoulder on the ground as well.

[peterpyro]

Sweet! Thanks guys!

 

Ill try that once I get a chance, cause at the moment Im running short on BP since Ive been advised not to make too much of it at a time, and will be needing to make some more plum charcoal.

 

I have made more stars since, and tested a couple of them just burning, and they were definitely not dry, but burned well (except for the inside) and Im exited for them to be dry.

 

Starting out as a noob here is probably one of the best things I could have done, since everyone can give me advice.

 

Thanks all for the advice! 😁

[cevmarauder]

For screens, McMaster-Carr sells stainless screens in 12"x12" sizes and various meshes for a really good price--I bought about a dozen for ~$60 a few years back and just built wood frames out of 1x4 lumber. Make sure you seal (stain optional) the lumber really well--I used a few coats of poly--and I then waxed them with Johnson's Paste Wax (I use it on everything. Everything.) Makes it easy to clean them; a quick rinse and scrub cleans pretty much everything off.