Re: Liquid shellac vs. powdered

On May 6, 9:10=A0am, John Reilly <strb...@[EMAIL PROTECTED]
> wrote:
> On May 5, 12:44=A0pm, marlowe <zde...@[EMAIL PROTECTED]
> wrote:
>
> > Is it possible to use liquid shellac cut with alcohol to wet stars in
> > which the shellac acts as a binder? If so, what would be the ratio of
> > shellac to alcohol? (The common stuff on shelves is a 3lb cut; that
> > is, three pounds shellac per gallon of alcohol.)
>
> > If it won't work, would it be wasteful to pay the $19/pound Skylighter
> > wants for powdered shellac, and does anyone have suggestions for other
> > suppliers?
>
> I ran across a Chinese firework formulary last year and several of the
> formulations for stars called for the use of "shellac paint". =A0The
> percentage of the dry shellac to alcohol called for was pretty high...
> 20% or more by weight, a I recall. =A0These were colored stars with or
> without MgAl and included some chlorinated resin as additional fuel to
> the shellac "paint".
> As Mike and Lloyd have noted, this hasn't been common practice in many
> years and I don't understand why anyone would choose to do it this way
> unless they have a cheap supply of mixed shellac varnish to get rid
> of.
>
> John Reilly

I got to thinking about this "shellac paint" I referred to above in
the Chinese compositions and dug them out.  One mix is a green nitrate/
magnalium strobe: "Green Scintillation Star".  I'd forgotten that it
also uses "rosin paint" in addition to the shellac "paint".  In this
mixture, they may use the dissolved rosin and shellac to protect the
magnalium and bind the mix.
Another formulation is a purple nitrate/magnalium star and calls for a
40% "shellac paint" solution.

"Green Scintillation" Star

Potassium Nitrate   13
Barium Nitrate         65
Magnesium alloy powder (uspecd. mesh and shape) 17
Sulfur                       5
Shellac paint (20%)  additional 14 parts
Rosin paint (40%) plus)  additional 4 parts


Purple Star

Stontium Nitrate    45
Copper Carbonate  14
Magnesium alloy powder 19
HCB                 10
Sulfur                4
Shellac paint (40%)  8


John Reilly