About the chinese "Time rain" composition

[Adrenaline]

Here`s some more time rain from new year`s eve.

TR + 1. Phiko Blue 2. Ruby Red 3. Emerald Green 4. Red strobe

 

http://pyrobin.com/files/TR%20cake.mp4

[MasterBlaster]

This is awesome! I've been wanting to try making some dragon eggs but bismuth is a little out of my price range right now. I'm definitely going to have to give this a try

[OldMarine]

Here`s some more time rain from new year`s eve.

TR + 1. Phiko Blue 2. Ruby Red 3. Emerald Green 4. Red strobe

 

http://pyrobin.com/files/TR%20cake.mp4

Please turn your phone sideways next time. Great stars but the video camera on your phone was meant to be widescreen.

[ExplosiveCoek]

Could you elaborate a bit on how they were made?

[Adrenaline]

Please turn your phone sideways next time. Great stars but the video camera on your phone was meant to be widescreen.

 

I didn't record the video myself, but I'll pass on the message.

 

Could you elaborate a bit on how they were made?

Are you referring to the time rain stars or the cake itself?

 

The microstars were 70% CuO 20% MgAl 10% Ti. Bound with NC-laquer. Wet the dry mixture with nc laquer and acetone until you can easily roll it out into a thin pancake of 1 mm thickness.

Then push the pancake through an 8 mesh sieve. Let the micro stars dry. Now you have to prime them. I use fence post prime with 7% red gum and isopropylic alcohol as a solvent. Spray the granules with

alcohol until they`re evenly wet and add prime. You can let them dry and then try lighting a few microstars with a lighter. If they only sizzle slightly and turn black then you haven't added enough prime.

Wet them again and repeat the process until you can light them easily with a lighter.

Ned Gorski published a great video about making micro stars:

Now you need to prepare your matrix star comp. You can use any composition you like. In my experience slow burning charcoal streamers give the best results.

The stars in the video were made with Hardt dragon's egg matrix.

Mix your matrix composition with your micro stars 3:1 by weight.

Wet the mixture with water und pump/cut stars. I used a 10 mm star plate for the stars in the video.

That's it.

 

Each shot in the video was one 10 mm star + 4 small coloured stars. Shot from 1/2 " paper tubes.

Unfortunately only the first three rows of the cake were recorded.

Edited January 14, 2017 by Adrenaline

[ExplosiveCoek]

Yeah, the stars itself indeed. I do like the combined effects of this cake.

 

Interesting that you can make DE without any lead or bismuth.. Is this a new development of some sorts? It sounds like a fast and easy method to make these stars.

[Adrenaline]

Well, I don't know who came up with this composition but the Chinese have apparently been using it for some time now.

However TR doesn't compare well with normal bismuth/lead oxide DE since it's not nearly as loud.

[Mumbles]

Are you sure they're actually using an all CuO based mixture, or is that off of a data sheet? I'm just checking, as data sheets aren't always entirely accurate.

 

I am with you though on the loudness. I made similar compositions to the above mix before it became widely publicized, but never gave it much serious consideration due to the volume. The 50:50 mix of bismuth oxide and copper oxide is good. I wonder how far you could push that toward copper oxide heavy while retaining a sufficient volume. Bismuth is not exactly cheap.

[Adrenaline]

It's of a data sheet. Seeing that the data sheet itself lists a variety of composition as "Time Rain" it is of course possible that they left out some factors.

In any case the data sheet doesn't specify mesh size of the MgAl, binder, size of the micro stars. I worked out a usable composition based on the data sheet by trial and error.

But I suspect that other mixtures might lead to the same or better results.

 

If you check the data sheet (http://pyrobin.com/files/Apex%20Pyro%20Compositions.pdf) you'll see that they listed TR sometimes with 60% Cuo 20% MgAl 20% Ti. Sometimes

It's 70% 20% 10%. There is even mixtures that apart from CuO and MgAl contain KNO3 sulfur and charcoal. (See page 32) Maybe the KNO3 sulfur and charcoal represent the matrix mixture?

 

In my experience the loudness of the TR microstars dependens on their size. However as opposed to bismuth type mixtures, making larger microstars actually decreased their loudness.

I once cut 5 mm cubes and they didn't crackle at all. They just gave a little pop when ignited.

If you keep the size fairly small they do make a decent crackling sound though.

[RichardH08]

This is a fascinating topic! Your work runs parallel to the research my colleague Ken and I have been doing over the last six months or so, and backs up many of our findings.

 

I don’t want to say too much just now, as we have recently submitted an article to AFN and – provided it is accepted for publication – we would prefer the details of our work to appear there first.

 

However, your comments about the prime sound familiar. From your description, it sounds like you use rather less NC than is present in more conventional crackle compositions. That might well be the reason that a somewhat more aggressive prime is needed. We use even less (grin) and find that the right amount and type of prime is crucial to success.

 

Also, it is true that they could be louder. Have you considered including a little aluminum in the mix?

[Adrenaline]

Yes I don't use much NC. Thank you for your input!

I have never tried adding aluminium. Are you talking about dark aluminium for flash powder?

 

Here's a video of a 2" inch time rain cylinder shell I built (unfortunately again no widescreen) :

 

http://pyrobin.com/files/2%20inch%20TR%20shell.mp4

[calebkessinger]

I like it.

That's a pretty cool shell!

[RichardH08]

Yes I don't use much NC. Thank you for your input!

I have never tried adding aluminium. Are you talking about dark aluminium for flash powder?

 

Here's a video of a 2" inch time rain cylinder shell I built (unfortunately again no widescreen) :

 

http://pyrobin.com/files/2%20inch%20TR%20shell.mp4

Nice shell!

In answer to your question, we find that any kind of flake - and especially dark - Al is too reactive and kills the crackle effect. A fine atomized Al seems to be more effective.

[rellim]

This is essentially copper oxide thermite. Here is an interesting video where it is used as a reactive target. There is also sensitivity testing where the guy beats on it with a hammer.

 

https://www.youtube.com/watch?v=316t0TM1EUU

 

 

 

 

[Yus]

Hi! I have possiblility to perform chemical analysis of same chinese pyrotechnic compositions. In matrix comet they used comp like Pb3O4/CuO/MgAl. Simple crackling stars contain mainly CuO and AlMg and as admixture Bi2O3 ~ 10%. Crakling flower additionaly include ~ 5 % Ti. Prime was also simple and consist of KNO3, KClO4, C, S, AlMg and unknown binder.

[Yus]

P.S. Chemical analysis - powder X-ray diffraction and/or SEM (electron microscope).