Hi,
When painting eggs, vinegar basically performs two functions:
1. Vinegar removes excessive fat which can be found on the egg shelf.
By neutralizing this fat, the paint will hold better.
2. The acid will bind with the paint, again assuring a better hold.
?Vinegar is used to neutralize excessive yolk fat, preserve it from
decomposition and to make dry pigment more mixable with emulsion. If
you add too little of it, overly fat paint may crack in time
especially when used over leaner layers of paint. If you add to much
of it, the paint may become milky-white and dry too fast, so that
you?ll not be able to use the "puddling" technique.?
Source: ?Lavendera.com?
http://www.lavendera.com/Paint%20Tech/egg_tempera.htm
And some tips on how to use the vinegar:
?Here is the general rule on how much vinegar solution is needed:
put the drained egg yolk back in to the egg shell (rinse it very well
before) and fill it to the top with vinegar solution. Now you know
your starting point. Stir emulsion and put it back in to the canister.
All eggs are different depending on the country and climate. Summer
eggs have more fat than winter ones.
By experimenting, you?ll find the appropriate amount of the vinegar
solution which may vary from 35% to 100% of the yolk.
Egg yolk is a natural emulsion which consists of 24% fat, 16% albumen
and vitellin, 9% lecithin and 51% water.
Egg fat consists of 3 acids - olein, stearin and palmitin. It dries or
hardens very slowly. The hardening process may take up to several
months. Albumen, and vitellin - are strong emulsifiers. Without them
oil and water could not have been in the state of an emulsion.
Lecithin - is a fatty substance which slows drying time of oils.
The egg yolk must be diluted with water or preferably with 2%- 3% of
organic acid solution.?
Source: ?Lavendera.com?
http://www.lavendera.com/Paint%20Tech/egg_tempera.htm
Search strategy :
Google : +vinegar +paint +egg
If you need any more information, please ask for a clarification!
Thank you,
paul_b_18 |
