KNO3 types

[Merlin]

Most of my nitrate (seedRanch)is free flowing granular like sugar. Some other sources are clumpy and hard. Today I opened a bag clearly labeled potassium nitrate but it looked and felt like high grade perc. I assume it must have been milled by mfg. Anyone come across finely milled nitrate? Would I be correct this nitrate might not be the best for glitter comps? Thanks

[NeighborJ]

I'm not quite sure what your concerns are but I assume you are worried about the particle size changing the effect or a difference in purity?

 

Most of the glitters I make use a finely granulated meal base so the particle size is not much of a concern and it consistently makes the same effect. The ones made with raw chems can change the effect quite dramatically if the chems are milled but they still glitter, it is a matter of preference.

 

As for a question of purity, you would need to try a small test batch, FWIW, I've not really noticed much change in effect between high purity and lesser purity KNO3, within reason.

[Merlin]

Yes. I have read that it is best not to ball mill glitter comps. My concern is that since this lot of nitrate is finely milled it might not be preferable for glitter comps. Since you use a meal base maybe the particle size of the nitrate doesn't matter.

Thanks

Edited July 29, 2018 by Merlin

[Arthur]

Mesh size may matter, but most times fireworks are professionally made with the cheapest grade on the market. If 95% will work you don't pay for 99.999%!

[Mumbles]

Mesh size can matter quite a bit in glitters Coarser materials, whether they're charcoal, metal, or nitrate can extend the effect or delay quite substantially. I prefer a middle ground. Too fine makes things too clean and uniform for my preference. Too coarse can leave fallout, make things last too long, and turn glitters into mediocre firefly effect. A good glitter needs some degree of randomness to me. When I had that sugar consistency nitrate, I ended up milling the KNO3/S/C for maybe 20 minutes to break it down. Including anything coarser than probably 60 or 100 mesh gave a distractingly long tail.

 

Most commercially milled nitrate is probably around -200 mesh or so. I'd use it as is, and not bother milling at all. It's probably what I'm moving too long term once I use up my granular stock. Much more convenient.

[Merlin]

Thanks Mumbles. I don't remember where I got the impression glitter components should not be milled. I will mill the granular nitrate 15-20 min. The bulk of my nitrate is sugar sized granules.

I came across 20 lbs I ordered at some point in the past that is milled extremely fine and probably contains cabosil.

Thanks much!

Edited July 31, 2018 by Merlin

[stix]

. . . I got the impression glitter components should not be milled . . .

 

I think that is generally true. Glitter comps should not me milled with metals.

ie. mill sans metals, then screen in the metals.

[Merlin]

Thanks Stix. Yes I would never mill metals. I just thought the nitrate should not be milled if it is fine and free flowing. I am clear on that now. Mine is granular like sugar and according to Mumbles lightly milling it is good.

[Mumbles]

While milling metal containing compositions is asking for trouble, I prefer no milling what so ever. I only did the bare minimum before to reduce particle size since I was starting quite course. This was mostly a mechanism to reduce thus fall out. Try it out both ways and see what you like. I'm not saying one way is better than the other, just different. You might have personal preferences on way or another though. If you were starting from finely ground materials, my suggestion would be to just screen the mix. Even with very fine materials, 2-3 passes through a screen is not going to provide the same intimate mixing as milling, which I see as an advantage some times.

 

Clean, uniform glitters definitely have their applications too of course.

[Arthur]

While every formula that exists has an ingredients list, and some have mixing instructions, they only refer to the materials that the designer had available at the time. I read an article about a historic firework design that ceased to be possible simply because the metal workshop that supplied the iron turnings moved onto the next job and the particular alloy and shape of iron turnings was never available again.

[stix]

. . . I read an article about a historic firework design that ceased to be possible simply because the metal workshop that supplied the iron turnings moved onto the next job and the particular alloy and shape of iron turnings was never available again.

 

That may well explain the "hoarding" behaviour of the amateur pyrotechnist.

[dynomike1]

Probably water soluble, if used as an Ag product.

Edited August 3, 2018 by dynomike1

[dynomike1]

This is milled N-1 W/ Alcoa 120. Are ingredients to fine of not?

 

[Sparx88]

That was really nice. Out of a 3" ball at 150' would make for a nice glitter willow long tail sparky twinkle good time

[Maserface]

Another thought, similar to what arthur stated above, is that the condition of materials used when formulating an effect might not be entirely well denoted.

 

I recall a story a friend shared, he had a container of milled potassium nitrate that had badly caked, beyond what could be screened back to life, and so decided to ball mill it. As an experiment he ran the mill longer than he had usually done, for 6-10 hours or so. When the newly milled material was used in familiar glitter formula (which my friend had made many times), it displayed a much more vigorous burn and thus effect; almost entirely different than he was expecting.

 

We don't often see precise material specification with formulas, so a little experimentation is needed. If the effect you are getting doesn't appear to match how the formula was described, the raw material conditions would be a good place to start troubleshooting.

[pyrojig]

This is a very valid point maserface made... It appears that the effect is effected in a way that is preferrred for many, by using freshly milled nitrate . It made a huge difference in several comps I have used. I tried very fine nitrate for some comps , and then compared to the nitrate freshly milled same size, and what a diff. !!! The sprittzle effect and tail where way more pronounced. I will always mill nitrate pre making glitters .

Thank you for point that out maserface

[Merlin]

I belong to a pay site and it's full of great info but seems like here is the place to get answers. Thanks for all the replies. I have several hollow core star pumps. I would like to make a spider type 4" cylinder. I am thinking 3/4" stars using a solid core primed on the end facing the burst. What are your opinions milled components vs Mike Swisher's non milled spider star. It seems the milled components would burn faster ensuring burnout before the pattern begins to droop. I sure want anything reaching the ground as a 3/4 star is pretty large. Also maybe a hollow core of c6 changing to color. Is this sound reasoning?

[AussieBombTech]

Thats honestly weird. Any kno3 Ive bought has been either granules or sand, its probably not uncommon to come across powder but I never have. It could be a mixed up order, if you think you have perch test it.

[Merlin]

I did test for perc and it is KNO3. You can buy milled nitrate it's just a little more expensive but it can save time and trouble milling and clean up.

[OldMarine]

I learned from Mike Swisher that the easiest method of determining if a powder is KNO3 or perc is a taste test. The KNO3 cools your tongue and is salty but the perc is tasteless.

[Merlin]

Yep I did a taste test but having never tasted either I devised a really clever test. Mixed what I believed was nitrate 7:3 with dark Al. Put in a tubed fused and sealed and lit it. No boom just spewed out and sputtered. Had it been perc I suspect there would have been some sound involved. Of course I diapered and treated as if it were perc. I wish I had got more it is the finest lump free nitrate. Totally milled it comes in handy at times when you don't want to mill nitrate.

My next task is to dry and mill strontium nitrate- it's like gravel almost. Seems to be hydroscopic.