prime

[Arw]

I made some blue star and prime them whit BP+5%Al.They were ignite in star shooter but when i use them in my shell they don't.
can you help me plz?
this blue.Add some ethanol and pump them.Al instead Mg/Al

[AzoMittle]

That's a solid formula, but you should try actually following it. Replacing the Al with the specified Mg/Al will definitely help; it doesn't list a mesh size but -325 should do the trick. For priming you will probably need something hotter, try either Spanish Prime, or Fencepost / Pinball Prime; if you are still having issues use a step prime.

 

Or, if you can't get Mg/Al try one of these:

 

63...Potassium Perchlorate
15...Parlon
12...Copper Carbonate
05...Hexamine
05...Red Gum

63...Potassium Perchlorate
14...Parlon
13...Copper Oxide
10...Red Gum

[Mumbles]

Also, blue stars are notorious for getting blown out if they're traveling too fast. Two potential fixes are to back off the booster if you're using any, or to just add more prime so that the actual star lights after they slow down a bit more.

[rogeryermaw]

i talked to brad about this same problem. hard breaks propel stars so fast that they cool below the ignition temperature of the blue formula. the prime burns off and fail to light the star. Brad's suggestion to fix this problem was to use thicker layer of slower burning prime or soft breaks. so ya..thicker prime works pretty well lol...

[Richtee]

I had issues with blue too. Was just getting them down when I was “forced into retirement”. Was trying a large grain er two of corned BP on the top of mix and the bottom of the star press before pressing. Was promising I think.

[MadMat]

I had hair-pulling, nightmares trying to get 100% ignition of my stars, until I started double layer priming them. I now use a hot prime with silicon covered with a layer of BP. This has worked for me.

My hot prime is (in parts not percent):

71 potassium perchlorate

14 charcoal

9 red gum

5 Mg/Al

3 dextrin

4 silicon

Basically, all my perchlorate oxidized stars get this.

Edited May 6, 2017 by MadMat

[davidh]

The thing to remember about thick or slow prime layers is that the longer it takes to light the star, the bigger the gap between the burst and the stars lighting. The commercial shells have very little gap. It's usually an easy way to pick out an amateur shell.

[Arthur]

One of the tests for fast black powder is to ignite some on a sheet of paper. Slow powder burns the paper, fast powder is gone before the paper can scorch. SO! Make slow powder for prime. With most powders all the combustion products are solids or gasses at flame temperature, which blow away as smoke or gasses taking heat away, with silicon in the mix the silica formed is a liquid so it sticks to the substrate (star) and transfers more of it's combustion heat to the star to ignite it more reliably. If your shells break to hard for your blue stars then take a layer of pasting paper off the design for blues.

[lloyd]

"The thing to remember about thick or slow prime layers is that the longer it takes to light the star, the bigger the gap between the burst and the stars lighting. The commercial shells have very little gap. It's usually an easy way to pick out an amateur shell."

-----------------

David,

I disagree. An 'less than artful delay' might be a sign of an amateur shell. How do you suppose they make peonies that only appear once fully-developed?

 

There are lots of very professional uses for long-delay primes.

 

Lloyd

[braddsn]

Hey Roger! Where you been? You must be busy I haven't heard from you in awhile! I have almost 400 shells ready for the 4th this year!! To the OP, like Roger and Mumbles said.. blues sometimes can trick you into thinking that their prime is not hot enough to light the star.. when in fact, they actually light pretty easy. They just tend to blow out easily if they are moving too fast. I like to use a blue comp that has at least a little bit of metal in it (the formula listed is great!), and I back off on the booster in my blues... actually, I tend to not boost them at all. Another trick that works good for blues, is to roll 3 or 4mm of C6 on them. It gives a nice charcoal streamer effect when the shell breaks, and insures that every star will stay lit (so the blue doesn't blow out). it acts as a prime layer, gives the star a chance to slow down a bit, and adds a nice effect. 'Most' of my blues are made like this (bleser blonde to blue, C-6/C-8 to blue, TT to blue, etc). I do have a few plain blue peonies, but not many.

 

Here is a glitter to blue shell that I tested a while back,

 

https://youtu.be/PXlQeuLfLaw?t=12s

[davidh]

Lloyd, I will capitulate that sometimes a long delay is desired between burst and the stars "showing". That said, new amateurs tend to use too much prime without realizing they are changing the effect.

 

It always amazes me how the small chinese consumer shells light their stars so quickly, and often from a hard break.

[lloyd]

David,

I'd agree with that, yes. And despite their prohibition here in the US, I'll bet you will find most of those 'fast lighting stars' contain (some) chlorates.

 

Lloyd

[OldMarine]

Seems to be a good thread for this question.

If I have a dextrin bound comp, should I use a like bound prime or would a prime using a different binder and solvent be acceptable? For example; A dextrin bound comp primed with monocapa using alcohol to bind.

[Mumbles]

There is something to be said for using a prime with the same solvent as the star. The outermost layer of star comp can be made to get wet or even a little dissolved and mix with the prime to make an in situ step prime.

 

I've also basically done what you described as well. Adding a hot prime with some red gum, or persumably phenolic, bound with alcohol. I personally like to apply primes sort of in the toro method when a mixture of slurry and powder is used. It makes it easy to do step primes between a hot prime and BP outer layer as well. A typical priming proceedure is a slurry and powder of a hot prime, then slurry of hot prime and powder of green meal or BP, then slurry of BP and powdered green meal. I'll often throw in a scoop or handful of corning dust or prime from previous batches that shakes off onto the final layer for a coarser final surface.

[lloyd]

Mumbles is exactly correct. But there are also occasionally advantages to using primes that will not dissolve the underlying star.

 

Take - for example - a star the main body of which is water bound, but hygroscopic after drying. Finishing it in a generous coating of a non-aqueous-bound prime can serve two advantages.

 

The first would be simply to not introduce any water to the dried but hygroscopic star. The second (if binders and thickness are chosen correctly) is to protect the body of the star from moisture intrusion from the atmosphere.

 

This set of conditions is not as likely to occur as those Mumbles's solution addresses, but there are situations where it can be of advantage.

 

Lloyd

[Mitchell]

I am unable to start a new thread so I will ask this here.

 

Can I use c6 rolled onto colored stars as a prime? Or should I include a layer of monocappa between the c6 and color comp?

[kingkama]

Which colours are you making, ie hard to ligth or easy? A layer of monocapa will do anyway a better result, if you put on a big layer will give a ghost effect ie the star ligth c8 let a goos tail then the colours ligth all together, the final effect is like diadem willow.