Jump to content
APC Forum

Recommended Posts

Posted

Alright, so finally I have found a star that won't light with just a bp prime.

What are you're favorite and hottest primes that are most compatible with every comp?

Posted
Alright, so finally I have found a star that won't light with just a bp prime.

What are you're favorite and hottest primes that are most compatible with every comp?

 

Tech,

 

A very experienced shell maker gave me some advice this last summer concerning primes. Do what the Chinese do. Roll a nice layer of a charcoal streamer gold or silver star comp on the outside of your stars as a prime. Pick a comp that is like 70-85% or more BP ingredients, with either titanium (silver) or ferro-titanium (blond). Then, prime again with meal powder. They'll light every time...even with extremely hard breaks.

 

Name: Gold Streamer

Source: Kyle Kepley

 

Potassium Nitrate 44

Charcoal, spruce, ball milled 44

FerroTitanium, 40-325 mesh, 60:40 15

Sulfur 6

Dextrin 6

 

 

Silver Streamer Star:

Name: Bright Silver Ti

Source: Ken Kosanke

 

Potassium Nitrate 64

Charcoal Airfloat 13

Titanium, grindings, 20-40 mesh 9

Sulfur 9

Dextrin 5

Posted
I add magnalium to some bp meal. But i have a whole bunch of formulas from passfire! If you have the money, i really suggest getting a passfire account.
Posted

Thats a very interesting idea Frank. I've thought about that, but at the size I've been working at, a small increase in star size makes a difference. Definitely sounds reliable though and I will give it a try.

And along the lines of streamers: What's the hotter ratio of KNO3 to charcoal? The extremes being something along the lines of tigertail (1:1) and at the opposite end bp (25:3). And leave aside the sparks which would of course help ignition, just the actual burning temp.

Posted
Primes should burn with lots of slag. This means that the heat is transferred along with the solids, rather than blown away with the gasses. Hence the use of a BP mix with added silicon which forms SiO2 as a heavy slag.
Posted

Has anyone actually tried and confirmed the fence post prime? I've tried just about everything, and am about ready to give up and go to step priming. I even tried what I was positive would be a sure bet. Lloyd S' pinball prime, with 5% silicon and BP over the top(containing about 3% silicon). I almost wonder if it was my BP on top. It's kind of old, and has some NC in it, so I wonder if it's not sticking well. I've seen the prime burn off, and fail to light the stars even.

 

I'm with firetech on this one. Size is important to me on my inserts. I also would prefer to keep them relatively cubical. Spheres don't make as nice of canisters.

 

BP will be hotter than TT by the way. There is a balance between burning fast and hot and lighting the star right away, and burning slower but not quite as hot, but staying on longer. On one hand you're making more heat, but could blow the star out if the prime burns off too fast. On the other, you are keeping prime on longer but also risk not lighting the star, or at least not all the way around it's surface.

Posted

I had some stars that gave me some trouble ( i assume it was from the high humidity this summer) So Out of ideas, I tried two primes.

 

1st prime:

80% Fast mill dust

10% Aluminum ( i used 325 mesh, others may work, but im not sure)

10% Magnisium 400 mesh (atomized was all i had on hand)

 

I misted a small batch of stars with a very dilute spray of NC. then dusted them with the prime. I layerd two coats on to the stars.

 

They took fire easly after that, although it seems a little heavy on the metal, it works fine.

 

2nd prime:

 

20% Potassium Perchlorate (40% if you leave out the chlorate)

20% Potassium Chlorate

20% Potassium Nitrate

20% Magnisum 400 mesh

20% Aluminum -325 mesh

 

Yes, It does seem to be a slow FP, But it works, I misted a small batch of stars with NC like above, and dusted roughly a teaspoon of this comp onto them. I repeted this once again with a few stars, so it would get a second coating, but worked the same with only one coating.

 

I did try it without the Chlorate, and it will work the same with the perch doubled.

Posted
Has anyone actually tried and confirmed the fence post prime? I've tried just about everything, and am about ready to give up and go to step priming.

 

What are you trying to light?

 

Ever tried (red) thermite?; was a classic choice at Shimizu´s age and should make quite a bunch of heat too. However, it´s rarely quoted nowadays...

Posted
It seems like I am blowing everything blind. My bursts are well proven, although I should probably back off a bit. Glitters, organic colors, metallic colors, you name it, I've been blowing them primarily blind.
Posted
Mumbles I think you're going to have to step [pun intended] up your priming.
Posted (edited)

Had a lot of problems in the past with primes, in all cases it has to do with how the prime is blended with the star mix.

 

Most common error is that the prime is added like a paint on a car, its not mixed with the surface off a star. It will definitely burn off like meal on rice hulls or corn.

Did a lot of testing on that subject, doesn't matter whether you use magnalium or rough meal added to your prime, if its not blended well with the star it burns right off. Have seen magnalium traces in the air from a prime while most stars didnt lit.

 

The best way is to make sure that the star is damp enough while adding the prime, put the whole batch in a (closed) glass jar and let it run on the ball mill for a few minutes (without the media of course). After that put some meal on it and run it again.

 

Right now i am very happy with the pinball prime (without Silicon), it will light everything including my AP and Ba stars. If you do it right you don't have to use meal on top of it. But to to be on the safe side i always put some meal on it.

Edited by Piet
Posted

Are you priming while your stars are still wet, or do you allow them to dry before adding your prime? I generally let my stars fully dry and rewet the surface until they begin to stick together. I then add my prime. All of this while constantly stirring by hand to replicate a star roller. The comp picks up and coats well. I've tried pinball prime, green meal + metals/silicon, straight meal, etc. I've had the best luck in the past with veline super prime and meal over the top of that. It's complicated and kind of expensive though. I've heard from Eugene Yurek that adding fence post (and I would assume others) with gum arabic realy makes it stick well.

 

I have a few things left to try

 

1. Fence-post prime

2. Slurry/Toro priming

3. Step priming

Posted (edited)

I always let my stars dry in a heated drying box for several days before i start priming. I use several glass jars on this process.

 

1, rewet the stars in a glass jar and let it run until the start giving off composition to the side of the jar, by this time they are all evenly wet.

 

2, put prime in a second glass jar and add the stars and let it run until there is no prime left and fully covered (no liquid added)

 

3, put meal in a third glass jar and add the stars and let it run until there is no meal left and fully covered (no liquid added)

 

Make sure the glass jar is 3/4 full with stars, otherwise take a smaller jar.

Sometimes you have to add more prime, but don't use to much. Better adding more than seeving it out when you use to much.

Let process 2 and 3 run for minimum of 4 minutes.

 

in cases of parlon bound stars i use a mix of acetone/spiritus (alcohol) 90/10 % but it all depends on the star mix you use.

Red gum dissolves very well in acetone.

 

This process is so easy and simple. I never clean the parlon bound glass jars afterwards, just trow them away in the glass container.

 

EDIT: it also works perfectly with cubic/cut stars, make sure that the jar is very full with stars.

EDIT: it takes a lot off time before the parlon bound stars are damp/soft

 

EDIT 3 :-) I am also using the glass jarrs to make little cut stars perfectly round.

After cutting approximately 200 grams of these small little succers i put them in the glass jar together with the sas and make them perfectly round to any diameter desired (haven't used my starmill for a year now)

This will probaly wont work with parlon bound stars, i don't even think about to try it. but for dextrin bound stuff its great.

Edited by Piet
Posted
That is part of the problem. I don't want round stars. They make for inferior canister shells and canister inserts.
Posted

I guess you’re cutting your stars then Mumbles?

 

When cutting stars I roll out the composition to desired thickness then lightly sprinkle prime over the top surface using a sieve. I roll this prime into the star "patty" to get good surface contact, the patty is then flipped over with a thin spatula and priming is repeated. The stars are then cut and dried as normal. Once dried I spritz them with gum arabic solution and add the prime of my choice to completely cover the star, this gives a fluffy outer prime that takes fire easily.

In canisters you may not need to secondary prime the whole star, just a light dusting on the originally primed surfaces so they take fire easer. I believe this as only one face of the star is intimate with the burst, therefore whole priming may not be necessary?

BTW I use a lightly milled greenmix with 5%Si and 5% MgAl as my prime.

 

Have you tried the toro priming on completed canisters, mentioned on passfire a few weeks ago?

  • 4 weeks later...
Posted
I've been blowing my organic stars blind recently. Or perhaps they aren't even lighting. Either way, I think they need a hotter prime. The only metal I have to use is aluminum. Any suggestions?
Posted
After priming them with greenmix, roll a thin layer of a slow burning charcoal composition (such as willow), so they have a moment to slow down before igniting.
Posted

I've heard of cut stars being primed before cutting!

 

Coat the rolling out place in the prime to stop the gooey mix sticking to the surface, then when rolled to the correct thickness, dust the top with prime, then cut the dough and dust again with prime to get some down the cuts.

Posted (edited)

I didn't get to light a new try-out flash today, it didn't go off using stabndard visco. The comp was:

 

61 Ba(NO3)2 (very fine)

10 Mg 50mesh

10 MgAl 180mesh

10 German Dark

9 S

+ 8% Sponge Ti

 

Does anyone know how i can light this flash ? Maybe use some 5:3:2 KNO3:-325mesh birght flake Al: Sulfur booster ?

Or do you guys have any other comps with none/little german dark and containg barium nitrate and magnesium ? I head something about a comp called 'thunderbolt'

Edited by yellowcard
Posted

The composition you describe sound more like photoflash compositions. They're not really designed to be used for salutes.

 

http://www.thegreenman.me.uk/pfp/flash.html#Photoflash%20I

 

As for why it isn't lighting, I'm not sure, but try losing the 50 mesh Mg. It's just going to burn up in the flame. It'd be much more useful if saved for strobes and the like.

Posted

I fence post primed some stars just recently for my pumpkin shells. Emerald green, Veline orange, purple as well. The orange and green lit fine in the shell. I then made a improved version of my 4" Ball of Doom and shot (flew) it. It had a emerald green ring a pistil of the purple stars. I have lit the purple with a basic bp type of prime, so the fence post should have worked perfect. It didn't so well. I had about one green star light. The salutes worked great, I think do the the fence post I dusted the fuses with. Only about half the shell had burst, and I boosted it like a full, normal shell. So it was a little over broke compared to a standard shell. The prime does seem to light the stars very easy on the ground, and burns off quite fast.

 

Note: I did use red alder charcoal, 100%. I have balsa, but its not milled down. I also did not mill the prime, as the Passfire note said it wasn't really necessary.

×
×
  • Create New...