Nitrocellulose Lacquer--easy dissolving smokeless powder

[SharkWhisperer]

For those who make their NC lacquer by dissolving smokeless powder in acetone...I've repeatedly come across threads (here and elsewhere) and other written pyro tips/protocols for getting good dissolving. It seems that many commercial smokeless powders, whether to formulation or extreme compression, can be difficult to get to dissolve, and sometimes require repeated stirring with wait times in between stir sessions. No longer.

 

Recently, when out at Cabella's buying smokeless powder and some new shore fishing lures, I impulsively bought an extra bottle of shotshell double-base powder because it was on sale. Turns out to be the best ever for making NC lacquer. It is Hodgdon's "International" shotshell smokeless double-base powder. No fancy name; no formula number The Hodgdon's International appears as thin round wafers approximately 1.5 mm in width/diameter and very thin, with separate and distinct burnt orange and green particles. It's specs show it to be a fast-burning formula because it's made for shotguns that require high-speed smokeless. Anyways, the stuff is an absolute dream for rapidly making top-notch beige-colored NC lacquer! It will dissolve to a syrup-like 10% solution in acetone with perhaps 2 minutes (!!) of decent shaking. No waiting. No clumping (as always, add while mixing to prevent clumps). None of that stir, stir, and stir again. The stuff is great and has performed excellently for tested uses (dragon eggs--it's the bomb!!; topping the ends of visco with a BP slurry to assist ignition, pyrogen component/adhesive with homemade e-igniters...). It's as messy as any NC solution to work with, but super simple to get to dissolve. The best smokeless powder for quickly making cheap & easy high-quality NC lacquer, in my experience.

 

I also bought slower burning IMR 3031 single-base powder (NC only, for when I pretend to be a purist). Incidentally, "IMR" is a 100-year-old designation that means "Improved Military Rifle". The IMR grains are short, dense, black extruded rods, approximately 2 mm long x 0.5 mm on the cross-section. Similar to a small grain of black rice but without the tapered ends. Graphite-coated & buffed shiny. It's more like the "typical" smokeless powder, with regards to getting it into an acetone solution and the dark black slime that results. This requires, as many before have reported, long dissolving times with extra stirring/babysitting. Final NC made with the IMR is high-quality, but slow to make lacquer with if you need it in a hurry.

 

Both powders described here are manufactured in Canada, so thanks Canucks!

 

Hodgdon's International is the best/easiest smokeless powder that I've ever found for quickly making NC lacquer. No hassle. No (visible) residue or precipitate. Stores well warm or cold. No NG separation. Pretty beige lacquer color is a nice change from the usual jet-black. And it makes absolutely dynamite Dragon Eggs!

Edited February 20, 2020 by SharkWhisperer

[Bigmark]

Good to know thanks for sharing this bit of info.

[nordicwolf]

Sorry to revive this old topic, too...

 

What are the ratios of Hodgdons International to Acetone to create a slurry suitable for good dragon eggs? I'm not clear on what the "10% solution" mentioned above refers to.

 

Thank you!

[stix]

Sorry to revive this old topic, too...

 

What are the ratios of Hodgdons International to Acetone to create a slurry suitable for good dragon eggs? I'm not clear on what the "10% solution" mentioned above refers to.

 

Thank you!

.

And dragging it up again...

 

I think SW means 10% by weight. That is, 90 units smokeless powder + 10 units of Acetone to dissolve it.

 

I've often wondered when making NC for DE's, what difference (apart from the safety factor), should it make using too much Acetone?

It may start off as a thin slurry, then when you add the other chems and mix it, the acetone is going to evaporate quickly enough to the right consistency for rolling and cutting.

 

Just a thought.

 

[EDIT] Correction as per SW below. I should have said: 10 units smokeless/90 units solvent/acetone

Edited June 9, 2021 by stix

[Richtee]

.

And dragging it up again...

 

I think SW means 10% by weight. That is, 90 units smokeless powder + 10 units of Acetone to dissolve it.

 

I've often wondered when making NC for DE's, what difference (apart from the safety factor), should it make using too much Acetone?

It may start off as a thin slurry, then when you add the other chems and mix it, the acetone is going to evaporate quickly enough to the right consistency for rolling and cutting.

 

Just a thought.

Yep, exactly what happens. to the point you get a block of NC. And it’ll collapse a glass jar. This- I know

 

On Edit: Ah, I see the point. Kinda depends if the mix yer binding is A solvent to a big degree. Might “leach out” some of the ingredients, causing a poor mix?

Edited June 8, 2021 by Richtee

[SharkWhisperer]

.

And dragging it up again...

 

I think SW means 10% by weight.

 

I've often wondered when making NC for DE's, what difference (apart from the safety factor), should it make using too much Acetone?

It may start off as a thin slurry, then when you add the other chems and mix it, the acetone is going to evaporate quickly enough to the right consistency for rolling and cutting.

 

Just a thought.

Yeah, I go weight/weight. Most folks prefer to use weight/volume, but acetone's less dense than water so 1 mL is not 1 gram as with water. Either way should work--you know how much NC per mL lacquer. The key is getting enough NC into your comp. Get a syrupy suspension/solution that pours slowly but reliably. A 10% w/v solution is just a little thicker, and works fine. Personal preference.

 

And I like the stabilizers in smokeless. Just used a last few drops from a solution made a year ago for rocket motor igniters and set aside and worked as well as the day I made it. I have pure NC too, but that's been in the freezer for 2 years now. No stabilizer and I'm probably not buying diphenylamine to stabilize it unless I'm going to use it all in a short time. I have no other use for diphenylamine (common stabilizer in smokeless and commercial lacquers; there are others but this one I see most often). And I don't mind the NG content in double-base, though I have single-base powders, too. Others subjectively report better results with DEs using NG from double-base; I can't tell a difference.

 

Acetone's specific gravity is 0.791 g/mL at 25C (77F). I round it off to 0.8 g/mL for "room temp" work, and call it good. For 100 mL of a 10% NC/acetone solution, that would be dissolving 10g of smokeless into 90g (112.5 mL; 90/0.8) acetone. This is accurate w/w, but is actually a little more dilute than w/v NC lacquer with 10g smokeless/NC dissolved in 90 mL acetone. I aim for 5% NC final in DEs/crackle, but you can give or take a decent margin without worry. When using double-base smokeless, I just lump the NG mass in with the NC calculations (I weigh total smokeless as "NC"). Added to the DE mix this makes a thick syrup that needs to have solvent evaporated off to leave residual NC. Acetone won't leach out any components--nothing else in DE comp is acetone soluble, and shouldn't really matter.

 

The trick is that the stuff is a lot more sticky when damp, and it goes from pain-in-the-ass sticky to workable within a minute or two, so you need to be attentive. Once it's ready to go (easily separates from the walls of your container with a wooden stick without leaving strands/residue is my gauge), you need to work quick to roll it out on prime, top prime, and cut. It's pretty much mandatory for me to have a spray bottle of acetone at hand to keep the top surface pliable and adhesive to prime, but if you let it dry too much before cutting you're going to have issues. I have tried screen cutting, but hand cutting gives me better control over the dough ball and provides a few extra valuable minutes for work before it dries up. Hard edges on cut DEs will round out when primed with an acetone-based prime, but I get more rounding if I do the next prime step right away instead of waiting. Still, many believe that rough edges on your DEs, even if coated with a round (eventually) prime layer helps them take fire. I've never had an issue with ignition with a hot/cold acetone-red gum based double-prime. Still wonder how the Chicoms get those tiny round crackle stars primed up; their starting stars must be tiny.

 

Also, I don't use the (expensive) Bi-heavy formulas. Typically I use about 35% Bi/40% CuO/15% MgAl (-200+325 or similar)/5% Al -325 (around 44 micron)/5% (by weight) NC from the lacquer. Works well. Could possibly reduce the Bi ratio even more, but haven't tried. If you're just starting out with crackle, I'd suggest keeping batches between 150-200g so you get a single decent handful of dough (the stuff's super dense) and get the feel of the details. Took me a couple of tries to get things right (for me). Taking notes at any hands-off break will probably prove useful in getting your technique right. Have your primes ready and have enough at hand.

 

Though I've never tried it, you can slow solvent evaporation rate in many instances (for example, when dipping igniters) by adding a fraction of methyl ethyl ketone (MEK), available for $7/quart (same as acetone) from HD, etc. This dissolves NC just fine, and slows the evaporation rate. I'm already waiting a half hour for acetone to evaporate to begin with in my DE mix, so if I wanted to add some it would probably only be at the very end, towards when I was getting ready to roll the eggs, so I had more working time.

 

Commercial NC lacquers for guitar finishing etc usually have a mixture of various solvents and don't go for the fastest drying with acetone only so you don't get an "orange peel" paint surface effect. Can't see why this wouldn't work for your DEs, but they might take a little extra time to cure and have the remnant solvent evaporate (overnight probably fine...). I get my acetone from the Chicom dollar store, but it's getting to be less and less of a bargain. Used to be 10 oz fingernail polish remover for a buck. Then the trade wars began and they shrank it to 8 and then 6 oz/container for a buck. And you need to read the label to make sure it says 100% acetone, not "Acetone, water...". At a buck for 6 oz, besides saving $1.50/quart vs HD (less if you buy it by the gallon for around $20), I appreciate having individual 6 oz containers (wish they were 10 oz still) that remain sealed until use. Keep in mind that acetone is very hygroscopic, so keep lids closed when not actively using it. Your "100%" acetone probably contains 0.5-1% water anyways (rough guess) but you really don't want to add more water into the mix or you risk trapping it inside your DEs (or any stars you make with it), which I'd rather avoid. If you're real anal, you can get molecular sieves, beads to absorb water from your acetone, but I don't bother... No idea of the hygroscopicity of MEK; would need to look that up. Ok, I looked it up--yes, like acetone, MEK loves water. Keep it sealed. MSDS available at: https://www.pure-chemical.com/msds/Methyl ethyl ketone.pdf

 

 

**Edited to make shorter paragraphs so I can keep our pal Stix alert and awake (long diatribes were making him sleepy :+] ). He also suggested I cut text length, but i disagree--info requires space sometimes, tsk tsk. You still awake, Stix?? Sheesh, it's pushing "winter" in Australia; maybe he's hibernating like a drop bear? "Drop Bear"? Hylarctos plummetus. Look it up, gringos. It's some serious shit.

 

Here's a typical Aussie Drop Bear:

Edited June 10, 2021 by SharkWhisperer

[stix]

. . . I think that was a typo above that said "90 units smokeless and 10 units acetone". . .

.

Yeah thanks SW , I've made a correction to my original post.

It should be the other way around: 10 units smokeless/90 units solvent/acetone.

Edited June 9, 2021 by stix

[Piccaso]

Fireworks cook book has started stock pure NC for less than current powder prices.

[nordicwolf]

bringing this up yet again...sorry...but thank you...

I read this thread again carefully, and I want to try @SharkWhisperer method of making crackle.  So I plan to make the following and will use the Hodgdon International as the 5 grams of NC per what I believe Shark was suggesting.

(35 Bismuth Trioxide) + (40 CuO) + (15 MgAl -200+325M) + (5 Al 325 (I think I have both spherical and flake will use spherical if I have it) + (5 NC)

That 5 NC will be 5 grams of Hodgdon International right out of the jar.

I will mix the fine comps first (3 times screen mixing through 20 or 40 mesh) then mix in the Hodgdon and shake it up.

To that I will add 45g acetone which for the NC would make 10% NC lacquer, adding in the acetone and stirring / letting it dissolve.

I think it would be great to make it this way without having to make NC lacquer first then add that to the comp.  Doing it all in one session would be simple and nice = I will try this.

Assuming I have made crackle granules by that method or some other (I have made 37.5 Bismuth Trioxide + 37.5 Copper Oxide Black + 25 MgAl bound with NC lacquer before (commmercial, not made with smokeless powder+acetone), screen cut through 8-mesh 2 times), assuming I have crackle, what type of prime would be necessary for use in a fountain?  And how best to apply it?

I have had mixed results with a prime made from (75 Potassium Perchlorate + 10 Pot Benzoate + 5 charcoal + 5 Dark Aluminum (eckart 5413H) +5 Silicon + 10 Red Gum) and using denatured alchol as the solvent.  The prime lights but often not the crackle.  Unfortunately I primed the whole batch and did not set any aside without prime to try those in a fountain.

Ultimately I hope to make crackle such that when placed on a small piece of paper and the paper is lit, the burning paper will ignite the crackle and it will go.  Well, ultimately I want it to work when ejected from a fountain.

Thank you.

[SharkWhisperer]

On 6/11/2024 at 1:21 AM, nordicwolf said:

bringing this up yet again...sorry...but thank you...

I read this thread again carefully, and I want to try @SharkWhisperer method of making crackle.  So I plan to make the following and will use the Hodgdon International as the 5 grams of NC per what I believe Shark was suggesting.

(35 Bismuth Trioxide) + (40 CuO) + (15 MgAl -200+325M) + (5 Al 325 (I think I have both spherical and flake will use spherical if I have it) + (5 NC)

That 5 NC will be 5 grams of Hodgdon International right out of the jar.

I will mix the fine comps first (3 times screen mixing through 20 or 40 mesh) then mix in the Hodgdon and shake it up.

To that I will add 45g acetone which for the NC would make 10% NC lacquer, adding in the acetone and stirring / letting it dissolve.

I think it would be great to make it this way without having to make NC lacquer first then add that to the comp.  Doing it all in one session would be simple and nice = I will try this.

Assuming I have made crackle granules by that method or some other (I have made 37.5 Bismuth Trioxide + 37.5 Copper Oxide Black + 25 MgAl bound with NC lacquer before (commmercial, not made with smokeless powder+acetone), screen cut through 8-mesh 2 times), assuming I have crackle, what type of prime would be necessary for use in a fountain?  And how best to apply it?

I have had mixed results with a prime made from (75 Potassium Perchlorate + 10 Pot Benzoate + 5 charcoal + 5 Dark Aluminum (eckart 5413H) +5 Silicon + 10 Red Gum) and using denatured alchol as the solvent.  The prime lights but often not the crackle.  Unfortunately I primed the whole batch and did not set any aside without prime to try those in a fountain.

Ultimately I hope to make crackle such that when placed on a small piece of paper and the paper is lit, the burning paper will ignite the crackle and it will go.  Well, ultimately I want it to work when ejected from a fountain.

Thank you.

1) Adding Smokeless Powder directly to DE mix. Curious what results you get. This sounds like it'd work great if you had finely powdered NC but maybe not with smokeless products. Hodgdon's International is thin circular wafers about 1.5 mm across. I'd worry that you will have difficulty getting a truly homogeneous distribution of NC in your comp, even if you cover it and let the comp set awhile after adding solvent. Seems likely you'll have focally high concentrations of NC from wafers melted in place and much less dissolved NC wicking in between. If so, this may compromise both the physical strength of your DEs (they're typically hard like rocks) and possibly also the crackle effect. If it works, the bonus is that you can add as much acetone as desired to get a working texture without having to consider amount of NC dissolved within it.

2) Priming DEs/Crackle. Proven with crackle used in hard-blown stars (shells, mines, and giant crackle balls/grenades) and fountains.

Taken from an old 2010 DE thread started by BJV that got lit up again in 2021/2022 "Dragon Eggs (Dragon Flowers)" regarding DE priming. When cutting DEs I roll the dough out on a thick layer of perc prime, slather the top with perc prime before/after rolling out the patty, and sprinkle some in the cuts after cutting. The outer BP-based prime can be added right away or another day:

Hot Perc Inner Prime

71% Perc

14% Charcoal (half generic hardwood airfloat/half ERC)

9% Red Gum

6% MgAl -200 mesh

+3% Si 200 mesh

 

Outer BP Prime:

67% KNO3

14% charcoal (same mix as above)

9% S

5% MgAl -200

5% Red Gum

+5% Si -200

 

*Applied with 91% IPA because I appreciate faster drying

*Have also used all commercial airfloat C alone to good effect but I added some hotter cedar because I had a bunch on hand. Sometimes use willow C. Works great.

*MgAl to heat things up a little; I've used a broader size-range -60 before too, to good effect.

*Red gum at 5% is probably sufficient for binding primer; I added more to hot prime because I had room and I know it's going to bind solidly. Want to try Vinsol.

*Si to melt into a hot molten glassy slag. Some recipes use up to 10%. I use what I found burns sufficiently hot and ignites reliably. To me the Si-slag from the outer prime is important in guaranteeing the slightly harder-to-ignite hot inner prime takes fire. Outer prime BP base fires up easily, especially with that S and a bit of hot charcoal. Once that perc prime ignites, nothing is going to extinguish it easily.

*Some like bumps on the outer prime from adding diatomaceous earth or sawdust for easier ignition. My outer prime layer is ugly and bumpy without and has never needed it. Plus, diatomaceous earth (mostly silica, some alumina, a little iron oxide) doesn't really burn so well and untreated sawdust isn't a favorite fuel although you don't really need to use much for bumps.

*I would imagine you could randomly change any ingredient up 1-2% and the next down 1-2%, or vice versa, and you would probably never know. Except Si, 3-5% is on the low-moderate range so I wouldn't want to use much less. These are well-oxidized comps that have hot fuels and do the job.

*Everything screen-mixed through 20 mesh until uniform, 3x usually does the trick.

*I've stored buckets of both as do-it-all primes for many months without special consideration except away from open flames and they always work well.

*The little bit of MgAl in my BP outer prime provides some extra heat energy without impeding ignitability. I sometimes add Al or MgAl to my BP when making match, just because. I speculate that the metal is particularly important on the inner prime for uniformly and rapidly transferring a bunch of heat energy to the entire DE surface nearly at once.

*You could likely find a decent Al to sub for the MgAl to good effect, but I like MgAl.