Re: NC Lacquer & Stars

Robert raises some legitimate questions, which I'll do my best to try
and answer.

robgood@xxxxxxxxxxx wrote:
hhc314@xxxxxxxxx wrote:

Also, since their are likely far better solvents for NC than acetone,
I'm tempted do so some experimenting with MEK (methyl ethyl ketone),
ethyl ether or similar solvent materials. Assuming that you don't
inhale too much of the vapor, is there any downside to using solvents
such as these?

Solvents "far better" according to what criteria?

Robert, I was referring to the increased solubility of NC in solvents
other than acetone. This becomes inportatnt when you are chopping up
old NC motion picture film base for your source of NC.

But back to the original poster's question: if the recipe just calls
for "10%" nc lacquer as binder, that alone would leave one in the dark
as to the TOTAL amount to be used in the recipe.

And as to another poster's question in this thread, I would assume
"10%" to mean w/v (weight of solute in total vol. of sol'n), but
several years ago the poster with "bitch" or something similar in hir
name took me (or maybe someone else) very hard to task for thinking any
right thinking person would ever use w/v concentrations!

Robert, I believe that I know the poster to which you refer so just
let's simply leave it at that.

There is a legitimate point of confusion here, in that those of us who
have taken chemistry in college realize that there are a number of
means of defining the concentration of a solute in a solvent. One of
the most comonly employed is defined as "the number of moles of solute
disolved in 1,000 grams of solvent. This is termed "molality, and what
led me to believe that a 10% soluton of NC in, say acetone, was based
on a weight/weight basis and not weight per volume, and although this
is not molality per se, you should be able to see the connection.

Obviously other systems are employed as well for expressiong the
concentration of a solute in a solution, most notible Molarity and
Normality, but these are seldom encountered outsid of scientific
venues. Mixtures of materials in a like state are the most common
examples of concentratins expressed in percentages, such as an
alcohol/water mixture, and even that gets trick because the total
volume of the solution is less that the volume of its components parts.
(Alcohol doesn't just mix with water, it partially disolves in it.)

The bottom line is that a 3-molal Solution or 0.5 normal soluton is
quite specifically defined, but a 10% solution is anbiguous without
additional information.

My question is quite sincere. I simply want to learn how someone in
the fireworks craft defines a 10% solution of a solute in a solvent. I
really don't know, since the terminlogy is not widely employed in
chemistry or physical chemistry in this context, except for materials
in the same physical state.

As still another question, I have a number of cans of Hercules Bullseye
and Dupont IMR 4895 on hand as surplus from earlier reloading
activities.. Unfortunately I believe that both of these are double
based powders containing a significant nitroglycerin component. While
I've read earlier posts indicating that these can be safely used to
make NC lacquer, my question is: "Would the residual NG increase the
safety risk when used for the production of "dragon's eggs" (crackling
microstars)?

Anyone here with experience doing this?

Kindest regards, Harry C.





Kindest regards, Harry C.

.

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