NC Lacquer From Ping Pong Balls

[Bju90]

Sporting powder requires a licence where I live and is quite expensive. I found some cheap ping pong balls sold by Kmart that are advertised as being made from Celluloid.

I dissolved them in Acetone. Once fully dissolved I added methylated spirits. A gooey substance precipitated out which I then extracted.

My intent was to remove the Camphor, since it is soluble in bothe Acetone and Ethanol but the NC is not really solube in Ethanol. These burnt a lot easier than the original ping pong ball or material that was dissolved then dried in acetone. Going off the burn test I'm moderately confident this removed atleast some of the unwanted material from the NC. Can anyone see a problem with this or a better way to remove some of the fire retardent and/or Camphor?

I'll test them on the weekend to see how it goes. 

It would be much easier to buy NC lacquer, I have found some products for guitars or RC plane dope. I wasn't sure if any additives/solvents would make these hit and miss. Guitar NC Lacquers don't really advertise whats in them. The Plane Dope in Acetone and Xylene. Would this work?

[AustralianPyromaniac]

The reason NC is used over a water-based binder like dextrin is that the microstars are often incorporated into another comp that is water-bound, and they must hold their shape in these conditions. Crackle can be bound with redgum, shellac, or dextrin water without issue, as long as the solvent is removed from the batch fast enough to prevent reaction of the metal powder.

NC, due to its own inherent flammability, improves the crackle over other binding options, but not that much. 

NC from ping-pong balls (with the camphor) is completely fine and there is no need to remove the camphor. The camphor acts as a stabilizing agent, preventing the spontaneous combustion of the NC due to degradation over time. Camphor is highly flammable itself, although does require external oxygen to burn. I am unsure if there are other flame retardants in the balls, if there are, they clearly aren't that good. The increased flammability after your extraction is probably just related to surface area change. 

Pure NC is not stable in storage and decomposes, releasing nitrogen dioxide which reacts forming nitric acid. Some form of stabaliser is extremely important, which the camphor offers. In smokeless power the stabliser is Diphenylamine (DPA). 

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Guitar NC is dilute and expensive, NC dope for model aircraft is much better and more concentrated. Both work ok and will bind the crackle without issue, but the dope gives stronger stars and costs less. 

[All10Fingers]

You can also geta stabilized nitrocellulose as a hoof treatment for livestock. Check wherever you can buy animal feed for farmers/ ranchers. It'll likely come in a brown glass bottle. Just tell em you have a goat with soft feet.

[Bju90]

Thanks @AustralianPyromaniac, very informative reply.

[Mumbles]

I think the other advantage to NC is that it provides a slight water-proofing for the crackle. I could see making stand alone crackle work with a water based binder. Crackle is a notoriously touchy effect, and changing the binder may require slight adjustments of the formula to adjust for slight differences in fuel value or burning properties.  Where I think issues may be encountered is when using it as a matrix effect. Migration of dissolved potassium nitrate, or maybe other oxidizers, has long been blamed for failing lots of matrix crackle comets.