crumbbum25 Posted January 18 Share Posted January 18 I am very new to this hobby and have mainly read/ watched Ned Gorski's stuff at skylighter and on YouTube. I've made pretty good black powder and will be making zinc stars. Ned used a "slow flash" booster in the tutorial and I can see why. Basically, I'm leery of flash, borderline scared. Perusing this site I stumbled upon the tpa flash thread. Some of the posts make me not so scared of it. Would that work too boost a shell in the way a little slow flash would? Or is there a better (safer) option? Link to comment Share on other sites More sharing options...
Zumber Posted January 19 Share Posted January 19 You might wait till you get good experience. Starting to make flash at begineer level is not recommended. Link to comment Share on other sites More sharing options...
crumbbum25 Posted January 19 Author Share Posted January 19 I assumed that too. I would rather stay away from it, honestly. Is there something that I could use to break a shell harder that's not flash? Link to comment Share on other sites More sharing options...
Arthur Posted January 19 Share Posted January 19 My understanding is that 3" shells should break well with plain 4FA, below 3" a booster may be needed, bigger than 3" then an inert filler may help tame the break, which may be needed if the break looks big but sparse. That filler may be most things, rice hulls to Rice Krispies. I have burst a big shell with two packets of Rice Krispies breakfast cereal and 3 pounds of meal powder thrown in over the Krispies, the Krispies hold everything in place the meal powder spreads everything out and lights all the inserts etc. Link to comment Share on other sites More sharing options...
cmjlab Posted January 19 Share Posted January 19 Advice in pyro is like an STD, you may not want it, but you're going to get it from everyone if you ask! (Kidding) but in seriousness, lots of people have their own experiences with what works and what doesn't, you get the pleasure of sorting through and seeing what works for you..... In that spirit, here is my 2¢ to further add to your confusion (and if you're afraid of flash....GREAT!, then you're more likely to ask some questions and do some reading before trying it out, and will hopefully be better prepared on how to do so more safely) I'm no expert cylinder shell builder, but I do build 300-400 shells a year the past few years. I learned in the first year that unless you have some amazingly hot B.P. you are probably going to want a booster for up to 3" and usually 4" if large breaks are your desired end-state. I'm a fan of Spanish Booster for 3" and 4" Cylinder and Ball Shells, have not tried it in a 5" Cylinder Shells. The Spa ish booster uses 50% Potassium Perchlorate and 50% Potassium Nitrate for the oxidizer portion, and Dark Al for the metal. It is still a form of flash and should be treated accordingly, but it does not seem to self contain when burned in a small open pile like typical 7:3 or Thunder #3. I imagine 1 could further "de-sensitize" it by using courser Al, but then I don't know how well it would perform as a booster. I've used "Slow Flash" (deceptively named, and still needs to be treated with respect) which works great as a booster and is more forgiving in how much you use. I've used various strength whistle, but mainly use my crap batches when I have them, as booster - it also works great on reasonable a amounts. Link to comment Share on other sites More sharing options...
cmjlab Posted January 19 Share Posted January 19 P.s. if anyone has some experience with nitrate flash broken shells, it's Sulphurstan IMHO. He has shared some sweet videos of large breaks, accomplished with nitrate flash (a version of slow flash I think). Link to comment Share on other sites More sharing options...
Zumber Posted January 20 Share Posted January 20 6 hours ago, cmjlab said: P.s. if anyone has some experience with nitrate flash broken shells, it's Sulphurstan IMHO. He has shared some sweet videos of large breaks, accomplished with nitrate flash (a version of slow flash I think). Here is 3 inch cake bursted with slow flash. But for begineer level it is not recommended. Link to comment Share on other sites More sharing options...
CHNO Posted January 20 Share Posted January 20 Flash: 67% Zn / 33% S Star: 55% KNO3 / 30% Zn / 15% S + 4% Dextrin Zinc Stars.pdf Link to comment Share on other sites More sharing options...
Zumber Posted January 20 Share Posted January 20 Slow flash Barium nitrate 2.0 Potassium nitrate 1.0 Sulphur 1.0 Fine flake aluminium 1.0 Link to comment Share on other sites More sharing options...
crumbbum25 Posted January 20 Author Share Posted January 20 Wow! Lots of great info. Thank you guys. That cake looked incredible. Link to comment Share on other sites More sharing options...
Zumber Posted January 20 Share Posted January 20 11 minutes ago, crumbbum25 said: Wow! Lots of great info. Thank you guys. That cake looked incredible. Thank you. Link to comment Share on other sites More sharing options...
crumbbum25 Posted January 20 Author Share Posted January 20 10 hours ago, CHNO said: Flash: 67% Zn / 33% S Star: 55% KNO3 / 30% Zn / 15% S + 4% Dextrin Zinc Stars.pdf 379.4 kB · 2 downloads Thank you. Link to comment Share on other sites More sharing options...
crumbbum25 Posted January 20 Author Share Posted January 20 8 hours ago, Zumber said: Slow flash Barium nitrate 2.0 Potassium nitrate 1.0 Sulphur 1.0 Fine flake aluminium 1.0 I found a mix of Potassium nitrate 2 Sulfur 1 Aluminum 1 I'll take your advice. I just want an as stable as possible booster that will not self confine in reasonable amounts. Preferably with a little "flash" as possible.I was thinking maybe 5 grams I'd use but I was basing that off of 70:30. Link to comment Share on other sites More sharing options...
Zumber Posted January 21 Share Posted January 21 Kno3 based flash needs lower activation energy than Bano3 or KP. Presence of sulphur aids lowering activation energy. Therefore this flash Is sensitive to strong Impact and friction. It is consumed as early as possible and not stored for very long period. Barium nitrate is recommended in humid area. Every flash needs to be treated with respect. There is another you can also try out is Replace Kp with Bano3 in standard 70 :30 mixture Barium nitrate 70 Fine flake aluminium 30. It avoids sulphur Bano3 wont absorb moisture in humid area. You have both choices to use flash as a booster. Just be aware and stay safe. Follow safety instructions. Link to comment Share on other sites More sharing options...
Sulphurstan Posted February 22 Share Posted February 22 On 1/19/2024 at 10:41 PM, cmjlab said: P.s. if anyone has some experience with nitrate flash broken shells, it's Sulphurstan IMHO. He has shared some sweet videos of large breaks, accomplished with nitrate flash (a version of slow flash I think). Thank you Zumber for the compliment, but, no, it was not me, too much afraid about flash (slow or quick or whatever flash 😉). I use mostly whistle mix for burst booster. Link to comment Share on other sites More sharing options...
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