Hot Igniter alternative without perchlorate

[oldfella]

 

I would like to make some of Ned Gorski's "Brilliant Green Rubber Stars" but I see they call for "Hot Igniter Prime".

I live in Europe where perchlorate is regulated.

Even if I made me a little stock just before the passing of the infamous regulating law, my precious KClO4 reserve is running out.

Would a black powder based prime be able to ignite those rubber stars?

I was thinking silicon or 200 mesh Mg/Al or both. Will a BP based prime have any chances?

Does anybody have a magic recipe to share?

[Sulphurstan]

Yep... Hot flames are often achieved by Perchlorates indeed...

 

Maybe using Mg (which Burns really hot), with an alcohol or acetone wetting, to avoid possible trouble with the Nitrate which could react with the Mg if water moistened?

Silicon is more for a durable hot slag, Imho.

Fe2O3, as catalyst, could maybe raise the temperature?

Just some thoughts..

Would be good to have advices from a more "chemical" member...

Edited January 21, 2021 by Sulphurstan

[SharkWhisperer]

I would like to make some of Ned Gorski's "Brilliant Green Rubber Stars" but I see they call for "Hot Igniter Prime".

I live in Europe where perchlorate is regulated.

Even if I made me a little stock just before the passing of the infamous regulating law, my precious KClO4 reserve is running out.

Would a black powder based prime be able to ignite those rubber stars?

I was thinking silicon or 200 mesh Mg/Al or both. Will a BP based prime have any chances?

Does anybody have a magic recipe to share?

I've used perc-based 1st primes on these (and similar) nitrate-based rubber stars with good effect. But I've also found that it's not absolutely essential. Try doing a step-prime layer with half star comp/half BP outer BP prime (with a little metal added in), then a layer of straight outer prime. It works. No perc needed. Make sure your KNO₃ is milled finely. Personally, my inner step prime BP component uses a hot willow milled BP (metal added after milling) to perk things up after being ignited with a stock outer slower screen-mixed BP layer made with crummy commercial airfloat (metal added after screening unless super fine).

 

For metals, stay with the MgAl that Ned calls for in his comp and in both prime layers. Al gets hot enough too. A little Si won't hurt. But I'd definitely stay away from straight Mg--For me it's just a pain in the ass to coat it with dichromate or linseed oil to prevent potential nitrate reactions. Sure, it's worth the effort if the Mg is a mandatory component of the main formulation (I don't use it often, still), but for a prime?? Naah. Not worth the effort. And not fool-proof protection for long-term storage, if needed, especially if not fastidiously protected from humidity/moisture. Mg alone has just never been needed by me in a prime for any comp.

 

I've used this approach with both his red and green formulations (and some similar magenta/purples using his red basic formulation with CuO added), and fired 1/4" cut stars hard out of 3" mines. 100% ignition every time. Haven't blown them in aerial shells, but can't imagine they won't light reliably.

 

I've used his perc hot prime formulation and BP outer prime (both with MgAl), as posted, and it works for sure. But I cannot tell a difference between ignition of these stars using this method versus a simple step-prime that i outlined above. 100% ignition with both. No perc. No Mg.

 

Edited to add that I typically use acetone/91% isopropyl (or dentatured) alcohol in a 50:50 mix to adhere those primes. The comp and step prime have parlon (acetone-soluble) and all layers have red gum (alcohol-soluble). Never had an issue getting the primes to adhere/incorporate. If I use 91% isopropyl instead of denatured or pure alcohol, I just ignore the final 4.5% of added water (and maybe a fraction more if acetone has some water in it--I don't worry), and never had an issue--still dries very quickly.

 

***Edited for grammar/punctuation

Edited January 22, 2021 by SharkWhisperer

[oldfella]

Thanks, I'll definitely try the step-prime.

I use vine charcoal for my BP, it gives very powerful BP (I really can't say how hot) and for the outer layer I normally use the same vine charcoal only screened with the rest (KNO3, S)

I too try to avoid Mg, I actually only bought 500g long ago but treating it was a pain in the back (even lower...) and I remember worrying about not doing it right. I never bought it since, also because I live in a very humid area.

I only have two taboos in pyro, one is magnesium and the other is (are) chlorates and chlorates I can't buy anymore anyway....

Thanks again, I will keep you posted.

[SharkWhisperer]

Thanks, I'll definitely try the step-prime.

I use vine charcoal for my BP, it gives very powerful BP (I really can't say how hot) and for the outer layer I normally use the same vine charcoal only screened with the rest (KNO3, S)

I too try to avoid Mg, I actually only bought 500g long ago but treating it was a pain in the back (even lower...) and I remember worrying about not doing it right. I never bought it since, also because I live in a very humid area.

I only have two taboos in pyro, one is magnesium and the other is (are) chlorates and chlorates I can't buy anymore anyway....

Thanks again, I will keep you posted.

Though I've never personally used vine charcoal, it has a long history of being outstanding for making fast/hot BP. So, that should be of great benefit to you, for sure!

 

Mg has its uses and some pyros use a lot of it. Chlorates, too, have their uses and some pyros use a lot of -ClO₃s. Both Mg and chlorates have earned the burden of well-deserved cautions because they can cause troublesome issues that almost always can be avoided by using alternate chems in their place. Not always, but most of the time there are safer substitutes. Still, these are chems that are well known, and many people don't have easy access to their substitutes for some pyro purposes. Like FP, these chems deserve respect but never outright fear of using them.

 

In your case, I think the step-prime might be an easy way to avoid Mg issues in the first place, and still get great results. My suggested step-prime approach is probably less expensive than using Mg, too, depending on MgAl pricing where you are. And KNO₃ is for sure less expensive than perc no matter where you are (that I'm aware of). I think you will enjoy good results. Rubber stars are so easy and fast to make, and they work really well for many colors. Living in the US, it's easy for us to forget how easy and inexpensive it is for us to access perc. So, I have a lot of respect for fellow pyros in other nations that need to create smart alternatives to using perc, or those ambitious (and patient) people who find a way to make their own perc. Impressive.

 

Anyways, I hope step-priming works out ok for you--I expect it will, especially now knowing you have great charcoal. Many people have relied on step-priming to get reliable ignition, using a wide variety of star comps. The idea is nothing new, obviously. Depending on your resources, you could learn a lot from doing test batches with only 100 g or so of stars. Please let us know your results and impressions!

[Mumbles]

I agree, step priming will work well for this.

 

Here is another option that should work well: https://www.amateurpyro.com/forums/topic/2676-fence-post-prime/ Fencepost prime is a BP based prime with silicon and diatomaceous earth. Silicon burns hot and slaggy, and the diatomaceous earth roughens up the surface to make it light a little easier. There are other purported benefits, but I'm a bit skeptical of the claims. It's effectiveness is not up for debate though.

 

I personally tend to like non-step primes for wholly mostly superstitious reasons. I make mostly cut stars, and it seems like every time I hold back comp for prime I almost inevitably over wet the comp it and need to use it to fix it.

[SharkWhisperer]

I agree, step priming will work well for this.

 

Here is another option that should work well: https://www.amateurpyro.com/forums/topic/2676-fence-post-prime/ Fencepost prime is a BP based prime with silicon and diatomaceous earth. Silicon burns hot and slaggy, and the diatomaceous earth roughens up the surface to make it light a little easier. There are other purported benefits, but I'm a bit skeptical of the claims. It's effectiveness is not up for debate though.

 

I personally tend to like non-step primes for wholly mostly superstitious reasons. I make mostly cut stars, and it seems like every time I hold back comp for prime I almost inevitably over wet the comp it and need to use it to fix it.

Doesn't fencepost usually have a water-based binder like dextrin also in it to keep the BP prime layer hard and intact? Wasn't included in the formulation at that link you provided (at least on the first page it links to...).

 

I've used hot BP-based primes as a 1-step, too--somewhat similar to fencepost--but add some red gum so I can adhere the prime with quick drying alcohol as the solvent. I also usually add a little MgAl -200 and Si -200 for some extra heat/slag, but have never bothered adding diatoms or sawdust (Veline's; also includes RIO as catalyst, no?) or similar for roughening the surface. Just haven't seemed to need extra texturing on the prime surface for any cut or pressed star comps I've used so far. I don't do much star rolling--except hand-swirling a bucket/pan for adding prime layers.

Edited January 22, 2021 by SharkWhisperer

[Carbon796]

Eugene is known for using, what he calls dextrin liquor. So his original prime formula, may not have needed an additional binder spec'd out.

[oldfella]

 

 

I didn't have much time to spend on pyro so I can update on the subject only now.

 

Having no diatomaceous earth on hand I decided to try without.

 

After screen mixing the prime I realized that I made just the regular 75/15/10 bp with an extra 5% silicon. damn force of habit.

I could have mixed some extra charcoal in but I decided to give a try to what I had.

 

So I made a micro batch of Ned's brilliant rubber red stars (which should call for hot prime), binding the comp with denatured alcohol (where I live isopropyl costs more than good vodka).

 

I used alcohol to be able to hand pump the stars, I figured that acetone and parlon would have made things sticky.

 

The next day (but the stars were dry after 3 hours) I dunked the stars into dextrin liquor and into the green mix plus silicon.

 

I tried 4 stars with a star gun and they all lit.

 

I also tried one on the ground to see how easy they catch fire and again it lit right away.

 

Now I should try in a shell but I am quite sure that they will work just fine.

 

For hard broken shells the fence post ratios of kno3-charcoal would certainly work better, but at least for these stars the diatomaceous earth can be omitted.

 

I'll update as soon I'll have a chance to try in a shell.

[justvisiting]

I have made the brilliant green rubber stars, various other colors, and the perchlorate-based silver streamers with the parlon binding. I make them by moistening the mixed comp in a Ziploc Brand freezer bag, poking holes around the edges of the bag, and rolling the comp out to a patty. The bag is cut away carefully. The patties are left to stiffen up, and cut into strips with a sharp knife. The strips are cut into cubes and dried. This is different than screen-cutting, and also different than Ned's other way.

 

In my case, the stars are rock hard and dry before priming. For prime, 50% of the batch weight additional should be allowed for. An excess of prime needs to be made up. For all these stars, I use the same prime:

 

75- milled potassium nitrate

15- commercial airfloat charcoal

10- sulfur

5- -200 or -325 mesh magnalium

5- silicon powder

5- dextrin

 

I take the stars in a gravy strainer, dunk it into a tub of water, shake off excess liquid and turn the stars out into the bowl of prime, and toss. I then gently sieve the stars from the excess prime, and toss them again in some plain scratch mix (no metals or dex). The final stars won't show any magnalium particles if the outer BP prime is sufficient. If the stars glitter from the magnalium showing, I'd spritz them with a little more water and toss in a little more plain scratch mix. I prime and dry them outside on a warm sunny day.

 

This was the priming method shown by Gary Smith, the original rubber stars guy. And YES, he did use water when priming the strontium nitrate red stars, just as I do now. It works fine, you just have to dry them well and keep them dry. I've never had ignition problems with any rubber stars, and I've only used this prime. I've done up to 6" ball shells with these stars. I haven't had to try another prime, so I didn't