[Sca-cooks] My last post on pysanky and vinegar

[Phil Troy/ G. Tacitus Adamantius]

Also sprach Phlip:
>Ene bichizh ogsen baina shuu...
>
>>  But while lye is certainly caustic, it equally certainly isn't acid. In
>>  fact, it's base. Extremely so. Don't know Aqua Regia.
>
>I'm quite well aware of that. But I perceive acids and bases as essentially
>the same thing, coming from two different directions. Are you aware of the
>pH scale, where Acids and Bases are rated as to their strength along a
>continuum, 1 being a strong acid, 14 being a strong base, and 7 being
>totally neutral, as in water, or the combined (certain) salts?
>
>>  I think it is possible that when  Stefan asked about acid, he did mean
>>  specifically acid...
>
>Maybe, but when you talk to someone with a chemistry background about acids,
>they're going to think of bases as well- just like you can't really think
>about owning and feeding a pet without taking cleaning up the results of
>that feeding  ;-)
>
>>  I'm pretty sure some mordants used are acid. When dyers in period used
>>  urine, modern dyers commonly use uric acid... I don't really know a lot
>>  about this, but it would be a place to look.
>>
>>  Anne
>
>Yes, there are several acid based mordants. Both acids and bases are used in
>a lot of different applications, in period, as well as now. But, don't
>forget the ammonia component of urine, either.

I think the point of questioning the use of a basic mordant in this
application is that egg shells are, themselves, a base, and that
acids will partially neutralize and dissolve them. Not sure bases
will do that, but would be surprised.

Adamantius