Switch to Rice Hulls?

[apcqazwsx]

I just made my first few aerial shells. These shells were all about 2 inches and used pulverone for burst. My bp isn't the fastest, but it seemed to do the job. I was wondering if I could used coated rice hulls instead of filling the shells with pulverone. The rice hulls would allow me to use much less comp but will they provide sufficient energy to burst the shell without a booster?

[Peret]

I've used both in 1.75 inch shells. The powder made a louder report but there was very little difference in the breaks, so now I only use coated hulls. This has two advantages - hulls use about half as much powder, and they can be crushed, making a tighter packed shell that doesn't rattle. Your shell will split when it reaches the same pressure whichever you use. Personally I don't boost my shells with flash or whistle, but if you wanted to do so, hulls is the preferred filling.

[Cookieman]

An H3 burst charge will work well for smaller shells without a booster. If you want to stay away from chlorates, any one of Shimizu's KP burst works well.

[KruseMissile]

An H3 burst charge will work well for smaller shells without a booster. If you want to stay away from chlorates, any one of Shimizu's KP burst works well.

 

KP burst is only good for shells 3" and up due to increased burn speed with greater pressure. A slow flash booster or whistle on bp coated rice hulls should be fine. GL

[Bangkokpyro]

If you are having problems with poor B.P burst in small shells not giving good breaks you might want to try the following as a burst charge.

Potassium Perchlorate 50%

Potassium Nitrate 25%

Airfloat Charcoal 25%

(add an additional 4% Dextrin as the binder)

 

You can make this as you would Polverone ( DO NOT ball mill it ) Granulate it to 4-12 mesh or coat it onto rice hulls in a ratio of 4 to 5 parts comp to 1 part hulls by weight.

This burst is far more effective than B.P without blasting your stars to pieces and very easy and fast to make.

Variations on this formulation are being used increasingly as burst in some commercial Chinese products.

It works well in canister shells as the central burst charge in shells up to 4 inch diameter with normal polverone packing the spaces between stars.

Edited August 12, 2010 by Bangkokpyro

[jwitt]

Coated rice hulls work well and they're easy to produce. Go for it- it's cheap and easy.

 

Just talked about it in another thread, but basically:

 

1) weigh out mill dust and dry rice hulls in a ratio between 4:1 and 6:1.

2) soak the rice hulls in warm water for 15 minutes or so.

3) add dextrin to mill dust. If you're using an entire batch of dust, keep a portion without dextrin for the end.

4) get a scrap of fiberglass window screen, panty hose, etc. Load up the wet hulls, take it outside, and spin it around in the air to throw off extra water.

5) put the hulls in a container with lid. Add an increment of powder, roughly 1/4 of what you have.

6) shake the heck out of it.

7) open container and observe. Powder is stuck to hulls. Add next increment and repeat until all of your BP + Dex is coated onto the hulls.

8) last step- throw in the no-dex BP. This gives the hulls a non-sticky coating to help prevent clumping while drying.

 

 

I had a batch of soaked hulls that I over-dried once- used my spray bottle to add a very very small amount of water to the operation and everything worked out. These dry in a few days in typical conditions. Watch out testing a little pile of 'em- they can propel around a bit.

 

Like the others said- they're light, flame propagates very well through 'em because of the shape, and they're crushable enough to allow you to really get a tight shell by mounding the hulls up a bit in each hemi before closing. Don't worry about lack of power- someone did a test between various methods of granulating BP, and also used rice hulls as lift in the test. They didn't lift as well as some of the better BP, but they worked!