11 replies to this topic

[Sam Miller]

I've recently made a batch of Emerald Green cut stars for 3" shells, about 3/8" cubes.
I was wondering about the strength of cut stars compared to rolled stars (my normal method) as the still seam crumbly after 2 days drying (paranoia of them all being blown blind!). Is it because they take longer to dry than rolled stars and I just need to give them a good week to dry?

Also these were made not primed and I was going to prime them in my star roller, when would be the best time to prime them? do they have to be completely dry or can they be primed after only a day left drying?

Thanks for the help!

Sam

[Mortartube]

Did you hammer the damp mix into a star frame with a wooden/rawhide mallet?

[Sam Miller]

No I wetted the mix into a ball then rolled it out flat with a rolling pin and had two 9mm dowel rods as stoppers.

Im hoping rolling them with prime will add more strength. I might be worrying about nothing as i haven't tested them but my 3" shells do break hard.

[megabusa]

Thats exactly how I do it using a rolling pin. Dry them for about a week & they should be fine. If they are crumby, they are still damp.

As I cut mine, I drop them into a bowl of prime before putting them on the drying rack. My prime is bp is straight out of the mill, with 7% Si added. Works for me.

[Sam Miller]

Thanks megabusa!

Would leaving them in an airing cupboard to dry decrease the time? Or can I make shells with them now? they're not being fired till the 5th Nov so would the stars still be able to dry inside of a shell?! 

 

Sam

[megabusa]

NO !!!

 

Do not force dry them, this is especially true for stars with a high charcoal content, or you can seal the moisture in, this being known as 'driven in'.

 

When I make stars such as Tiger Tail, I dry them in the cold garage for about 2 weeks or so.

 

They need to dry in ambient conditions before going in to the shell. They will not dry in the shell & will dampen the burst, so this would waste your effort.

 

Weigh them now & every day, recording the weight each time. As the weight levels out, they are ready.

[Vic]

Not wishing to course controversy, but I have never had high charcoal content stars being driven in, were the drying temperature is below 80°F. I believe the Chinese at times, have left the final drying out when the fireworks are fully assembled, though I doubt if this is the norm.

[wayne]

Thanks megabusa!

Would leaving them in an airing cupboard to dry decrease the time? Or can I make shells with them now? they're not being fired till the 5th Nov so would the stars still be able to dry inside of a shell?! 

 

Sam

 

Hi Sam,

 

Exposed compositions of any kind should not be stored (drying is technically storage) in a domestic dwelling, so an airing cupboard is definitely NOT a place to dry stars.  Just think of the consequences of those stars igniting through normal means or even spontaneously, it could be quite devastating.

 

It goes without saying that all experimental pyro should be conducted with safety as the first priority, so please review your current procedures to ensure you're working as safely as possible.

 

Cheers,

 

Wayne.

[megabusa]

 

Not wishing to course controversy, but I have never had high charcoal content stars being driven in, were the drying temperature is below 80°F. I believe the Chinese at times, have left the final drying out when the fireworks are fully assembled, though I doubt if this is the norm.

 

 Hi Vic,

 

I have experienced this with charcoal streamers & they never actually dried even after several weeks.

 

I tried to break them up again in the mill, but my media became coated with the comp as it was still damp.

 

Ended up binning the lot  

[Sam Miller]

Hi Sam,

 

Exposed compositions of any kind should not be stored (drying is technically storage) in a domestic dwelling, so an airing cupboard is definitely NOT a place to dry stars.  Just think of the consequences of those stars igniting through normal means or even spontaneously, it could be quite devastating.

 

It goes without saying that all experimental pyro should be conducted with safety as the first priority, so please review your current procedures to ensure you're working as safely as possible.

 

Cheers,

 

Wayne.

 

I do make sure I am extremely safe with everything I do And hence I asked first before actually putting them in the airing cupboard

Thanks

 

Sam

[Sparky]

Sam - You don't mention the comp and binder. 

[Sam Miller]

Sam - You don't mention the comp and binder. 

 

Sorry for the late reply Sparky!

The comp was Emerald Green and the binder was 25/75 Iso/H2O

 

I left them 4 days to dry then primed them then left them another 3 days to dry and they worked perfectly

In my case anyway I got a lot more stars for my batch when cutting rather than rolling, maybe my rolling skill needs improving


Sam