Rolled stars blowing blind

[dynomike1]

Fence Post Prime....make it, use it, like it....never go back to anything else.

Looks like the further i go the worst i get.I have tried 2 step prime and Fence post prime in plastic shells, and i still cant get Green stars to light. I checked my prime and it looked thin so i reprimed with Fence post again. If this doesn't work, the only two things left is more glue or strapping. The formula is

 

Barium nitrate 50

MgAl 18

Parlon 16

Red gum 10

Dextrin 5

 

If there is something i'm missing, i hope someone can tell me. There is not much info on building plastic shells, except what Harry puts out.

[ollie1016]

Looks like the further i go the worst i get.I have tried 2 step prime and Fence post prime in plastic shells, and i still cant get Green stars to light. I checked my prime and it looked thin so i reprimed with Fence post again. If this doesn't work, the only two things left is more glue or strapping. The formula is

 

Barium nitrate 50

MgAl 18

Parlon 16

Red gum 10

Dextrin 5

 

If there is something i'm missing, i hope someone can tell me. There is not much info on building plastic shells, except what Harry puts out.

 

Are you missing perc?

[FlaMtnBkr]

Msybe try the priming Ned Gorski describes in his brilliant rubber star article.

 

For making plastic ball shells try to find Lloyd Sponenburg's plastic ball shell class article which uses a flash bag and jumble filling the shells. I will also do a search and see if I can find it.

 

Edit: Also, I think the fence post prime is recommended at a 1-1.5 mm thick. But if the first prime isn't hot enough to light the star, it doesn't matter how hot what you roll on top of it is.

 

Are your green stars bound with dextrin and water? What is the formula of the prime rolled directly on the green and what is it bound with?

Edited July 22, 2013 by FlaMtnBkr

[dynomike1]

Formula does not call for Perc.Whats funny the red stars light. The only difference is Barium and Strontium nitrate.The 2 step was red rubber prime. The prime will light them with a torch. Everything bound with 75-25 water/alca. Sounds more and more like there not staying in the shell long enough.

[Carbon796]

David Bleser's Round stars & shells is specific-ly about plastic shells.

That looks like a modified version of skylighters blinding red,also sub-ing the barium nitrate.

 

.50 strontium nitrate

.08 KP

.18 parlon

.12 Mg/Al. -200 mesh

.05 sulfur

.05 air float charcoal

.02 red gum

.05 dextrin

 

The charcoal and sulfur will make it easier to light and stay lit. I first started with, and have always used this hot prime, I've never tried another one. I've never had to, its never failed to light anything I've made. Silver waves,flitters,illuminating stars, and AP one's. And of course the usual KP,Mg/Al,parlon based colors

 

BAFN. III Pg 115

 

.73 Perc

.12 red gum

.05 air float charcoal

.01 cupric oxide

.01 iron oxide black

.04 dark aluminum. I use 5413 H

.04 dextrin. I use SGRS

 

- Rich

Edited July 22, 2013 by Carbon796

[Carbon796]

Barium nitrate stars, are frequently noted as being harder to light than strontium nitrate stars. I bet your close maybe try an extra layer of hot prime on your green stars before your BP prime.

[dynomike1]

I forgot about that. That will be my next step if this shell does not lite tonight. I re read it and that is a well glued shell.I took 5 stars and spaced them .5"-.75" apart and lit the first one and it lit the 2nd one and so on. So maybe i have enough prime now. Edited July 22, 2013 by dynomike1

[Mumbles]

I've used the red (and corresponding green) that Rich posted with good success. Fair warning though, red and green do not have the same burn rate. Green has always about 20-30% faster with my materials, so you sometimes need to adjust star sizes to get them to burn out at the same time if you're using them in the same shell.

 

Good luck, and let us know what you find.

 

Do you ever video tape your shells? There is a difference between just not lighting, and blowing out from high wind velocity. One requires a hotter prime, and the other just requires a thicker prime. These types of stars aren't as prone to blowing out, as say blue stars are though.

[FlaMtnBkr]

Do you think the addition of a couple percent of barium carbonate would slow things enough to have similar burn rates?

[dynomike1]

We tried to vidieo last nights shell, but where i am testing at we don't have much room, so it's hard to get on the shell. We will try again tonight. Maybe i will have a prosperous video tomorrow. Prime is as follows

KNO3=65

Airfloat=15

Sulfur=10

D.E. powder=5

Silicon=5

Dextrin=4

Bound with 75/25 W/A

[dynomike1]

Here it is another bad video. At least some of the stars lit, looks like around 5 not much for a 3" shell. I guess i will put more prime on them tomorrow.

PS The burst was 5:1 Rice hulls.

http://youtu.be/472c3ZAEXtA

Edited July 23, 2013 by dynomike1

[Carbon796]

@ dynomike1

 

I don't see it listed but what are you using for burst. Also it seams like you've primed these a couple different times, are you sure they are completely dry? You can place 10-20 stars in a ziploc, and squeeze the excess air out and close. Fold the bag over close to the stars and place them in the sun, on concrete or a brick. Stars on the top side of the fold, check the bag for any condensation in about 20-30 minutes.

[dynomike1]

I dried them in a dehydrator today. I cut one open i'm not sure if it's enough prime

http://www.myhostedpics.com/images/dynomike1/img0027c.jpg

Edited July 23, 2013 by dynomike1

[pyrojig]

I believe your fine on prime. The prob is probably in the star being driven in. Just a thought. It would not light one mix and then fail another close color mix.

[Zumber]

We tried to vidieo last nights shell, but where i am testing at we don't have much room, so it's hard to get on the shell. We will try again tonight. Maybe i will have a prosperous video tomorrow. Prime is as follows

KNO3=65

Airfloat=15

Sulfur=10

D.E. powder=5

Silicon=5

Dextrin=4

Bound with 75/25 W/A

I am sorry but what is D.E.powder??

[Xtreme Pyro]

Mike it seems to me you have enough prime, Ill second what pyrojig said. Maybe they're driven in? If you continue to have star ignition problems, maybe try the step prime I posted in the second post here: http://www.amateurpyro.com/forums/topic/8621-rolled-stars-blowing-blind/?do=findComment&comment=113215

 

I've always had good luck with it.

 

I am sorry but what is D.E.powder??

 

Diatomaceous earth. It adds some "fuzz" too the prime, making stars light more reliably.

[dynomike1]

Well Rich the star burns fine when you light it with a torch or even in a mine. They Were dried for a week before they were primed. The red star similar to it lights fine. This is the second batch i have had trouble with. Maybe i need to try another green star.

[mabuse00]

The mentioned nitrate-only star formula imho is the best there is for red/green stars.

The barium version is indeed very stubborn, but the performance is worth the effort.

 

Be sure to use something perchlorate based for the inner prime layer and if you dont step prime them, at least try to wet the stars until their surface starts to dissolve, to get the changeover between prime and star as smooth as possible.

 

 

I used a modified pinball prime with good succes:

KClO4 70

Charcoal 10

Redgum 10

Si 63µm 8

MgAl 40µm 2

PVB +2,5

 

On top of that greenmix with +5% Si +2% PVB.

 

(I bind them with denatured alcohol and PVB, what makes them even harder to light, but avoiding any drying problems with the strontium version. Lots of bad odour from the denaturing stuff, but rock-hard stars in 12 hours)

 

 

Fair warning though, red and green do not have the same burn rate. Green has always about 20-30% faster with my materials, so you sometimes need to adjust star sizes to get them to burn out at the same time if you're using them in the same shell.

That is exactly what I tested on last NYE on a little rocket and both where perfectly matched. I used 53% barium- and 50% strontium nitrate, 12mm x 12mm pumped.

 

See attached file.

 

If strontium is slower, it's (imho) not dry.

Edited July 23, 2013 by mabuse00

[dynomike1]

These were shot out of a 2" star mine while ago.00 i'm still working on what you said.I'm getting close to the end, i'm waiting on chemicals that i orderd.

http://youtu.be/r59Km6dyzlk

[mabuse00]

To slow on the trigger

 

Seems like the prime burns off without igniting the stars.

Which prime was it, fencepost?

[Zumber]

Thank you Xtreme.........

[dynomike1]

2 step and fencepost.

[dynomike1]

I learned how to use a I phone. Right handed not left handed. Anyway i think i got a good video this time.

http://youtu.be/3AAetxRr87s

[pyrojig]

I know Im coming into the posts a bit late , but what size mesh was the Bano3 . If not milled to a fine powder, it will give slow to hard to light stars. Also It appears that the prime isnt even taking fire from the last video. Confinement is another possibility. Inadequate confinement will lead to many stars not getting fire transferred to them.

[PyroCube]

Hi all

 

I made a bunch of rolled stars lately. I used quite much water so the surface got

kind of " sealed " and now I`m afraid that they`re not going to light properly. What do you suggest for roughening

up the surface so I get a 100% chance of ignition? I tried to roll them in my granulated blackpowder, but it didn`t work

out very well... I havent got any diatomaceous earth here so that comes out of question.

 

Thank you,

Greets