Same Day 6" shell

[aerialpyro]

I need to test some 6" shell ideas. What type of composition and construction should I use? Fallout isn't an issue, as I have plenty of space that isn't prone to fire. I need to be able to do everything from mixing composition to launching the shell the same day at a single location.


So far, I am thinking I should use welded plastic shells as I don't have a pasting machine, and can handle the fallout for now. What do you suggest for binder and composition types? Is it feasible to build a shell like this? I am trying to test some stuff to help me be able to justify the cost of purchasing or building a magazine.

[PyroJoeNEPA]

A complete one day build is an aggressive project. The down side is that you could not roll stars large enough for a 6" shell and have them dry in the same day. You could use cut parlon stars--but I have not had good results with them any larger than 5/16". You are looking at half inch stars for a 6" shell. If you had the stars pre made it would be another matter.
You can use 6" plastic hemi's although I don't like using plastic. Paper always seems to break harder for me. There is a nesting hemi [Japan] that uses two hemi's sealed with white glue that you can make & shoot the same day. If you are not familiar with them send me a PM & I will send you the info on where to locate them.

When you said "what type of composition"--could you clarify that question?

[Kenny East]

I was going to say cut stars would be the way to go for sure, rolled stars large enough for a 6 would take a long time to dry. Could make a lampare shell, not very colorful but quick to make. Falling leaf shells can be made pretty quick also.

As for the plastic hemisphere, you still need quite a few layers of pasting to have a good break, and survive the lift charge.

If you have a user permit, check with your local distributors. I have a 1.3 guy here that sells stars ready to be made into shells... Tons of colors and sizes.

[aerialpyro]

The question on type of composition is basically what type of binder/solvent combination will be able to dry quick enough. Cut stars for sure. I don't need super good stars/colors for this, but I do need something to mark the expansion path and indicate the expansion pattern. The nesting paper hemispheres sound interesting. If I can solve the storage problem, then I can get licensed to purchase the components and this gets much easier. My state allows use and testing by manufacturers so if I can find a way to do it without transporting/storing the stuff I should be fine. Theoretically I should be able to do it right now, except the same day requirement may end up making it to difficult. I may be able to boil the test down to some other shape that will take less stars and throws things in less directions then a sphere, but I want to simulate a spherical shell as close as possible. The imaging requires this be a ground burst test, so lift charge isn't a big deal. Space, and a safe place to observe is, but I think that part is already sorted.

[PyroJoeNEPA]

Look into the "rubber stars" --the parlon series with acetone binder. They dry very quickly & can be used the same day.