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Acid expert


#1

While you are discussing acids,I realize it is disposal subject,would any
expert be able to tell me an acid or combination,that would dissolve the
mineral Zoisite,while slow enough acting,or uneffective to underlying Ruby
crystals? Mark Liccini

http://www.LICCINI.com


#2
...tell me an acid or combination, that would dissolve the mineral
Zoisite,while slow enough acting,or uneffective to underlying Ruby
crystals? Mark Liccini 

G’day; Zoisite is a calcium aluminium silicate: (CaAl3[SiO6].[OH] and ruby
is aluminium trioxide: Al2O3, corundum. The only acid in which either of
these is soluble is hydrofluoric acid, HF. The ruby might be less soluble,
but I rather doubt. it. I don’t know any reference book which might help,
unfortunately. You’d have to try it yourself. I’m sure you doubtless know
how dangerous hydrofluoric acid is already - but my wife used it for many
years performing the analyses of refractory clays. With somewhat inadequate
ventilation, I might add. And she is 80! Cheers, –

John Burgess


#3

Mark, I can’t answer your question…but since I own a 17lb. chunk of
Ruby-in-Zoisite, and don’t own a saw large enough to slab it, I would be
-very- interested in -learning- the answer! (Oh bother!..I
probably can’t find a nonreactive container big enough to immerse this
thing either! ) -Pete-


#4

Hi Mark and John,

In dentistry we use a HF substitute. It will dissolve the dental
porcelain right off of the gold. There are 2 products that I know of-
No-San and Stripit. If you wish, I would be happy to try it out for you
if you would send me a small piece of the material. E-mail me privately
if you wish.

Warmest Regards,

Skip

Skip Meister
@Skip_Meister
Orchid Jewelry Listserve Member
N.R.A. Endowment &
Certified Instructor
in all disciplines
Certified Illinois D.N.R.
Hunter Ed, Instructor
ICQ 37319071
"No man’s life, liberty or fortune is safe…while our legislature is in session."
Benjamin Franklin


#5

That’s interesting, Skip. I just came in late on this thread. We use a HF
substitute for cleaning up titanium before heat colouring or anodising (or
after a colouring mistake). It’s a dilute mix of sodium flouride and
hydrochloric acid. Weaker than hydroflouric but probably somewhat safer.

I’m interested in other substitutes, as this one has a short life after
mixing - couple of months.

‘MultiEtch’ from Reactive Metals reactive@sedona.net
<www.reactivemetals.com> (800 876-3434) is a HF substitute. BUt we may
find that we have import restrictions here for such products.

What’s in No-San and Stripit?

Brian

B r i a n A d a m J e w e l l e r y E y e w e a r
@Brian_Adam1 ph/fx +64 9 817 6816 NEW ZEALAND
http://www.adam.co.nz/ Wed4Aug99


#6

Brian, These are 2 products used in the dental lab industry to remove
porcelain. I really don’t know what they contain. Call a dental lab and
ask what they use to strip porcelain in Kiwiland. Two online supplier of
dental lab supplies in the U.S. are http://www.darbylab.com and
http://www.zahndental.com.

I just called the manufacturers of the products.

No San - HF acid and a trace of sulphuric with surfactants and such. They
were not specific.

Stripit - 7.32% HF acid, .85% Sulphuric acid plus various surfactants and
wetting agents.

They are called HF substitutes!;o)

These acids remove all traces of investment in a short time when put into
a covered plastic beaker in the ultrasonic. They also remove firescale.
I hope that this helps. The stuff is really nice to use compared to
regular HF.

Regards,
Skip

Skip Meister
@Skip_Meister
Orchid Jewelry Listserve Member
N.R.A. Endowment
"No man’s life, liberty or fortune is safe…while our legislature is in session."
Benjamin Franklin


#7

G’day; If almost any fluoride (calcium, sodium, potassium, etc) is heated
gently with a little 10% sulphuric acid - or even sparex, hydrofluoric acid
will be generated. I happen to use an excellent flux called "Easy-flo"
which contains a small quantity of a fluoride, and if you were to have a
look at my pickle pot when clean and dry (not very often, that) you would
see that the inside has a frosted appearance, where the acid has combined
with the fluoride in the flux to etch the glass surface. Thus, a fluoride
plus an acid will etch away porcelain, clay, glass, fired enamel, etc in a
very controllable, and not particularly hazardous way. Is this esoteric
any use to anyone? Cheers

        /\      John Burgess
       / /
      / /      Johnb@ts.co.nz    
     / /__|\
    (_______)   It's springtime in Mapua Nelson NZ.  Stroll

through the village and you can (almost) hear Johann Strauss’s
’Voices of spring’!