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says...
Hello all.
Does anyone have information about dewaxed shellac composition.
I usualy bought shellac from a hardware store and I am not sure that
its the best shellac to use on finishing, hardware store could not
provide me any specifications.
So while looking at chemistry supplies providers if found this shellac
**************************
Alcohol Insoluble 0.72%
Color Lovibond 12
Acid Value 65
Fusion Range 73°C
Iodine Value 14.5
Humidity 1.33% in Alcohol
Wax 3.42%
Ashes 0.145%
Rosins NIL
Colofonía NIL
****************************
It says 3.42% wax, I wonder if dewaxed means 100% wax free or not ?

Also regarding shellac preparation, I use 15gr shellac + 120 gr alcohol
for 1 pund cut and 30 gr shellac + 120 gr alcohol for 2 pound cut. So I
tried this time to use hot water to heat up the flasks with shellac,
stirr every now and then, for 2 days but shellac just wont dissolve, a
large amount of flakes just wont dissolve totally and just sit there.
In the beggining the solution is like a suspension but after a couple
of days it cleared up and the undissolved matter kind of 'vulcanised',
I mean that it formed nuggets and precipitated on the bottom. For one I
am happy that the solution is nice and transparent but otoh I wish that
all of it dissolved. I guess the shellac from hardware store I am
buying is not top notch quality. I guess Id have to get some dewaxed
from shellac.net, happens that I am in Mexico and its kind of hard to
get something good quality with full specifications on it.

Konstantin.

I assume you aren't buying dewaxed shellac, and if that is the case,
then the wax will always be suspended in the mixture and if it sits for
a few days, it will settle to the bottom of the jar. My guess is you
are seeing mostly wax falling out of the solution. Also bear in mind
that since shellac is a natural product produced by insects, it will
have impurities in it and you are supposed to strain it before using it.
What you are seeing sounds normal to me and if you separate the clear
solution from the precipitate on the bottom, you will have made your own
dewaxed shellac. Also beware of the quality of your alcohol as well as
the shellac. If the alcohol has much water in it, it won't dissolve the
shellac very well. Alcohol would be a good thing to buy from a chemical
supply house, because the quality should be very high. Keep your
alcohol closed tightly at all times, because it will draw moisture from
the air. If you can find Zinsser Seal Coat in Mexico, it is a dewaxed
shellac already made for you in a 2 pound cut. It is very common in the
US.