Rolled stars blowing blind

[LambentPyro]

WOW !!! I missed a lot !!! some how it went from stars blowing blind ,to blowing behinds (in a liquid state of matter!)!! .

 

Hahahaha!! Yeah, we went a little bit off-topic!

[yvariro]

Hi guys,

 

Tonight I shooted my firsts 4" shells! (and others rocket wich performed really nice )

 

There was 2 shell,one did not light from the lift(i surely damaged the time fuse during the pasting) the other

Kinda blew Blind... Picture per picture I saw that 80-90% of the stars lit,but just 20% did ignite completly

Do you know why ? It's very strange!

My stars was rolled 10-12 mm Tigertail to red( because i was afraid to have this issue I primed them) ,I used 4:1 BP on saw dust as break charge and 3gr of KP 7:3 flash(2microns Al) with a tad of magnalium (for a hotter break ? )

I pasted the shell with the 3strip method,and applyed 6layers

 

The stars was dry,so it may be the break wich was too powerfull ? But if it's that why others (20% of the stars) did light ? And why the rest did ignit on the first part of the break and then did nothing ?

 

It will be very nice if you could help me because it's my last problem on shell making,I just have to clear this !

 

And I have to thanks all the user of this great forum for their help,tutorials,and post wich informed me a lot,now my unique problem is here,all other things are cleared thank to you

 

For the moment I can't send the video,and I will be not in my home for 5days

 

Thanks you

 

Yvariro

[Bonny]

What red were you using? Tiger tail is not a very hot mix to light colour stars. Did you use a relay mix in between the layers? As for the damaged timefuse on the other shell, was it crossmatched in any way or primed on the end?

[yvariro]

Hi

I was using Buell red and yes I used a relay mix/prime on the core (I tested them on the ground,all was good)

I understand that without the video it's hard to determine the problem,but I'll post it when I'll be back.

 

The problem is they lit first (the stars,not the core) but then did not ignite...is it the break charge wich was too powerfull ? Too much confinement ?

The other stars wich ingnited completly did not have à coulour transition problem

 

For the other Shell all is my fault and I know why It failed... I've juste been too lazy for cross matching à time fuse so I used a 3.5mm visco... (rolled into à tube obviously) Wich can damage easily than time fuse...

 

Yvariro

 

[PyroCube]

I never had ignition problems with buell red so far, it seems to be very easy to light. I don`t think your break was too hard, good manufactured

and fully dried stars can survive a really hard break .

Maybe your cores weren`t completely dry. If they were, the prime could be the problem. How thick was your prime layer and what`s the composition?

 

 

Greets

[yvariro]

Hi,

Thanks you for your reply but I think my post was'nt clear,the problem come from the outer layer of TT composition wich did not ignite,not the inner core of buell red,wich ignited succesfully on the 20% of the stars wich ignited first.

I think the stars was dry because i dried them 5 days under the sun, I did not have driver-in problem

I stored them at open air,(I live in the south of the France wich have hot and dry summer days) then I filled the shell with it,pasted and dried the shell 4days under the sun again...

I primed the outer layer too even if it was TT for avoid blowing blind problem

The prime was BP with 10% Si and 10% MgAl on the core and on the TT layer.I always put 1/4 of the weight of stars composition in prime,so the prime layers was 1mm thick.

I really don't know why it failed

 

Yvariro

[yvariro]

 

Why the TT did not light even with the prime ?? It's really getting out of my nerve! The break was not very hard,I have really no Idea why it failed,

I know this problem is frequent,and you don't want to answer because the forum have à lot of informations,but it did'nt help me... The major problem of à blowing blind is the prime used on the stars,but my stars was dry,and primed TT composition ...

I've made winokur 20 to green core today,what would you suggest me ? Change the prime composition for see if it's the problem ? But the prime wich I currently using is pretty good,I really don't know what to do... I documented myself a lot before to make stars,shell I really don't know from where it failed if it's not the prime or the humidity of the stars

[TYRONEEZEKIEL]

If you are having trouble getting TT to light, there has got to be a problem with the construction of the stars. Tiger Tail is a very easy formula to take and transfer fire from my experience. Are you drying your stars to constant weight?

[ExplosiveCoek]

Probably your stars are still wet. I've had the same thing happen for me .

[yvariro]

TYRONEEZIEKEL,

 

What do you mean by drying the stars to constent weight ?

The TT composition was rolled on the red and primed core,with water as solvant,and à bit of alcool for reduce the surface of tension and avoid rasberries looking stars,then I primed them with BP w/ Si and MgAl

 

ExplosiveCoek,

 

I dried my stars 5 days under the sun,i tested them on the ground and they ignited rapidly

How long did you dry them when you had this problem ?

 

Greets

 

[dynomike1]

Ok 1 more time, I'll bet your shells are breaking to fast. In other words the shell is not stayin together long enough for the stars to light. A problem that i had with plastic ball shells and canisters. Say you made an 8oz. batch of comp., you have 8oz.. Now weigh your cores. Now you roll stars, weigh them while they are still wet. Now when you think they are dry weigh them and see if they 8oz. + cores. Edited August 27, 2013 by dynomike1

[PyroCube]

I don`t think your break is too hard. How does your primed surface look? To light easily, the surface has to be roughened up in some way.

This can be achieved by adding some wood meal or diatomaceous earth to the prime. If you haven`t got one of these you can just roll them

in green mix after rolling the stars. Don`t put any binder into the green mix, just dump the rolled stars in and let them take as

much powder as possible. If you just dry the stars after rolling the surface get`s rock hard and sealed. That dry rolling in green mix

definitely prevents that and gives you a better chance of ignition.

 

5 days in the sun are definitely enough when living in south of France. My 12mm stars usually dry in 3 days in the sun.

 

Greets

Edited August 27, 2013 by PyroCube

[burningRNX]

Maybe the problem lies into your burst carryer, something with flame propagation?. ricehulls have lots of open spaces.

[yvariro]

Dynomike1,

So if I had understand,for having à better chance of ignition I have to paste more(less booster) then the shell will be more resistant to the pressure,so the stars will be more in contact with the fire ?

And thanks you for explaining this very good idea that I never think of ! Definitly do that every time now...

 

Pyrocube,

Your right,the surface of my stars was smooth,they looked like polished... It may be that !! But they did a bit rasberried,they was a bit deformed...

Thanks you for explaining very completly this method that I never applyed too ,IMO roughened up the composition was utile for very hard break not for BP with booster break.I'll re-roll my stars and see the result.I hope that was the main problem !

 

BurningRNX

 

I'm currently using rabbit litter wich is saw dust as break,I get good result and no blow blind with my canistershell,but I'll buy ricehulls soon,it's more easy to work with since all the shell maker use it,the unique problem is that it's expensive where i get it..

 

Thanks you all for your helpfull reply,I really appreciate it!

 

Greets

 

[dynomike1]

3g 70/30 should do it.

[yvariro]

Hello

 

I applyed 3gr of 70:30 for boosting and 12layers of pasting on the shell wich failed... So I will put 2.5gr and 16 layers right ?

 

[PyroCube]

No, don`t do that. I did some perfect 4" shells with only 8 layers of pasting. (3g 70/30 Flash)

16 layers would be way too much. You will have better chance of ignition without the flash booster, but well primed

stars will survive a strong, flash boosted break.

I`m shure your star surface is just too smooth. Roughen it up with something and dump them in

green mix after rolling and you will have full ignition. BTW: You really don`t have to prime TT stars,

just roll them in green mix after wet rolling and you`ll be fine.

 

 

Greets

Edited August 28, 2013 by PyroCube

[Mumbles]

You're getting all sorts of advice here, and much of it is good. I'd suggest taking it one variable at a time though so you know what didn't work the first time.

 

To be honest I'd sort of start over. I'd go with unboosted 4" shells. There is absolutely no reason that TT should not light from a straight BP break. From this starting point having everything light properly (hopefully), you can adjust pasting and booster to your liking. It's a lot easier to enhance a break until it doesn't look quite right than it is to try to back it off.

 

I also do really like the suggestion to make sure the prime layer is kind of dusty, fuzzy, or rough.

[Jakenbake]

I agree as well. My first year at making shells i used bp and booster. Sad to say i was chasing my tail all over trying to get the stars to light. So this year i decided to use no booster and i had much better results. 0 booster+fuzzy stars=

[TYRONEEZEKIEL]

If your stars are shiny smooth, then that is your problem right there. Your stars should feel rough, almost like fine sandpaper.

 

Drying to constant weight means that weighing the same batch of stars day after day, you will not see a change in weight anymore due to no more water evaporating.

[dynomike1]

Hmmmmm I thought he was using plastic shells.

[pyrokid]

When rolling stars, my technique has always been to finish the stars with a dusting of the appropriate BP composition. My ignition rates have always been good. My theory is that since I don't spray the stars after the last dusting, their surface is less uniform and therefore takes fire more reliably.

[pyrojig]

Ive got a interesting prob .

1 kilo of Ap white strobes where made up ( rolled with 5% Nc laq. )using very course magnal. My magnal is 36- mesh and the stars when lit with a torch produce a very pronounced and delayed flash. The down side which I expected ,was they are near impossible to ignite . I rolled .5mm of shimizu strobe prime, then 1mm of green mix with finer magnal. I have ignition on the ground , but from a star gun I get 0% ignition. The prime always lights but leaves the star blind. Can I salvage these beauties by rolling a heavier layer of comp over them( like glitter) and hopefully they have slowed enough to ignite ? I have already added 1 more 1mm layer of fence post prime to the comp and still have 0% ignition in the gun .( same binder was used through out the mix, no water binding )

[yvariro]

Hi all,

I'm back!

Thanks you for all you reply I just have to do all your advice in practice and we will see if it work!

Yeah that right I thinks I've been a bit too pretentious to apply serious booster for the first time !

 

Anyways,here is the video,after reflexion I think the break is definitely too much powerfull,next time no booster or less than a gramm,and the same confinement

 

I hope (if I can on my phone ) to put some pics of the stars wich was used in the shell in this topic too

 

http://www.youtube.com/watch?v=uqUC7b7Vlcw&feature=youtu.be

 

Thanks you again !

 

Yvariro

[TYRONEEZEKIEL]

That is exactly what my blind stars have been looking like. I started having blind stars again. Maybe I get rushed in my rolling and dont spend the time step priming over a proper length. In any case Im gonna roll yet another layer or two of prime on top and see how that does