Star prime

[Foxfire87]

I will be making simple stars since I'm just beginning, tiger tails, I read they dont need primed but it's good practice to prime all stars, so my question is, is there a universal prime that works well for most everything? Or what would be an easy to make prime a beginner could start with and how to apply them to stars? I read so many different ways to prime and I'm getting confused. As I said for a while I will be working with very simple star compositions. Any input or thoughts would be very helpful

[starxplor]

I have not had to prime charcoal stars like tiger tails when pumping/plating as the ends are rough enough from handling to take fire. I have only made a few shells in total over the years, so I may not be the best person to listen to though.

[Foxfire87]

Yes I have read they dont need primed. I guess it was really more to get in the habit and feel comfortable doing it. So I want to start with an easy prime method. Also, can I make tiger tails without a pump or tool? Just roll it out and make small balls out of it?

[starxplor]

There is a method called 'cutting stars' that only requires a way to flatten the damp mix and then cut it. My first cut stars were done with rolling a consumer HDPE mortar over putty with a couple of pencils with the flat sides as stand offs for consistent height. After that, I used the sharp edge of a plastic ruler to cut the flattened patty first into strips, then into cubes. They take longer to dry because of the higher moisture needed to make a putty.

These stars all worked well in a shell.

 

Look up videos on 'cut stars' for more info.

[Arthur]

Somme stars need prime, some do not.

 

Primes can be simple BP slurry, or a sulphurless BP, or something hotter burning like BP +10% metal. Just occasionally there is a real need to double prime with two comps to accommodate the sensitivities of the star and break powders.

[braddsn]

Foxfire, to answer your question... priming is critical, most of the time. Guys will build shells but have a hard time figuring out why the breaks aren't symmetrical..when in fact, they may be symmetrical but half of the stars don't light so you can't see them. There are different primes that need to be used for different applications. Charcoal stars (like TT, C-6, C-8, etc) don't need prime usually. Other stars like glitters, I like to have 1 layer of prime. Lastly, for color stars, I will either use a 2 layer prime system (a hot prime, followed by a bp prime), or a single layer of monocapa prime. But to get back to your original question.... a fantastic "basic" prime is bp + 5% silicon and 5% diatomaceous earth. You can put that prime on many stars and it will work great, and takes fire easily. Star ignition is critical for a great shell.. and make sure you are getting enough prime on your stars. Later as you advance, and start breaking shells harder (boosting), you will need to adjust your priming to accommodate these breaks.

 

https://youtu.be/gQmW64LhbTo?t=7

[MadMat]

A few tips, you can take them or leave them. I started out cutting stars. My basic materials were: dollar store flexible plastic cutting boards, wooden doweling which is the diameter of the desired star size, plastic wrap, something to use as a rolling pin (large diameter wood dowel) and a 10" drywall taping knife for doing the actual cutting. Put the moistened star compound on the cutting board, cover in plastic wrap place the wooden dowels along the sides as a guide and roll out the compound. Try to work the compound into a square as much as possible. Cut with the taping knife. As far a priming is concerned, I use a two step prime on most stars and it has worked well for me. The first layer is a perchlorate based prime with 5% silicon. The top layer is BP, but with a few considerations. First off, I only ball mill my BP prime for 1-1/2 to 2 hours, not the four hours I mill my BP for everything else. Why? I once read that to test if your BP is really burning at its maximum potential, light a small pile in the middle of a large piece of paper. Well milled, fast burning BP will burn so fast, the paper will not start on fire or even have any holes burned in it. My BP will actually do this and this is simply not good for transferring heat into a star for ignition. So, a shorter milling time will produce BP that will ignite easily but burn slowly enough to make sure it ignites whatever is underneath it. I add a small percentage of dextrin to both prime compounds and also make a dextrin solution to bind the prime to the stars. When making this solution use hot water to dissolve and activate the dextrin. I then put my stars in a large bowl and spray them with the dextrin solution (a trigger hand sprayer works great for this), I then sprinkle some of the prime into the bowl and shake/swirl the stars around until they are coated. Once dry and hard you then repeat with the next layer of prime. Don't be skimpy with the prime you want a nice thick layer. It's not important to have a complete even layer over the entire star, in fact if it comes out a bit lumpy that's even better because a rough surface will take fire easier. I have had great success with this priming method, even with hard breaking shells or hard to light star compounds

Edited January 2, 2020 by MadMat

[Carbon796]

Most people will use scratched mixed BP ( screened only ) for the final prime. There's no need to ball mill it at all.

 

Use two bowls for priming, it will be cleaner. And, more of the prime will go on the stars. Spray and tumble stars wet in one bowl. Then dump them into a dry bowl that already has some prime in the bottom. Sprinkle with more prime over the top, close lid, then toss and tumble to coat.

 

If you coat your star patty generously with prime, before you roll it out. You won't need to cover it with plastic wrap.once its rolled out, rub a thin layer of prime back over the top, before you cut it.