Carolynn Palmer on sun 27 jun 99
A while ago, I asked fellow Clayarters to guess at what a commercial pottery
was using as a suspension agent (flocculant?) in his glazes and the answers
were: CMC, Epsom Salts, TriSodium Phosphate and bentonite, among others.
But just recently someone posted about adding muriatic acid to glaze as a
thickener and wouldn't that also act as a suspension agent?
Carolynn Palmer, Somerset Center, Michigan
Carolynn Palmer on sun 27 jun 99
A while ago, I asked fellow Clayarters to guess at what a commercial pottery
was using as a suspension agent (flocculant?) in his glazes and the answers
were: CMC, Epsom Salts, TriSodium Phosphate and bentonite, among others.
But just recently someone posted about adding muriatic acid to glaze as a
thickener and wouldn't that also act as a suspension agent?
Carolynn Palmer, Somerset Center, Michigan
ababy sharon on mon 28 jun 99
From the few materials I tried,Epsom salt, cmc and a material called "Kur"or
"Cur" from my supplier. The first one was the best.Cmc might be good too,but
it is very hard to proper and pass it through 80 mash strainer.
good luck and if the new material is good late me know.
Ababi----- Original Message -----
From: Carolynn Palmer
To:
Sent: Sunday, June 27, 1999 06:45
Subject: suspension agent for heavily fritted glaze
> ----------------------------Original message----------------------------
> A while ago, I asked fellow Clayarters to guess at what a commercial
pottery
> was using as a suspension agent (flocculant?) in his glazes and the
answers
> were: CMC, Epsom Salts, TriSodium Phosphate and bentonite, among others.
>
> But just recently someone posted about adding muriatic acid to glaze as a
> thickener and wouldn't that also act as a suspension agent?
>
> Carolynn Palmer, Somerset Center, Michigan
>
Bruce Girrell on tue 29 jun 99
Carolynn Palmer wrote:
> But just recently someone posted about adding muriatic acid to glaze as a
> thickener and wouldn't that also act as a suspension agent?
Acid will work only in glazes containing clay. The acid changes the
electrical charge at the edge of the clay platelets causing them to clump
differently. Frits, having no net electrical charge, will be unaffected by
the acid.
Bruce Girrell
in Northern Michigan, who just finished a glaze experiment that involved
100% Frit 3110 and who can attest to the fact that in about 30 seconds the
whole mass settles to the bottom and hardens like a rock.
BTW: 60% frit + 40% EPK didn't settle at all (but then it didn't fuse at
^04, either). 59% frit + 5% EPK + 36% flint melted well and had a nice
crackle, but still settled to the bottom rather badly.
A work in progress
Tom Buck on tue 29 jun 99
Muriatic acid is the commecial name for Hydrochloric Acid (HCl), a
strong mineral acid. In a glaze mix (water + components) the HCl would
make it harsh on hands, depending on how much is added, other factors.
The HCl supplies H+ ions and this highly mobile ion would have an
effect on whether ions from the glaze solids would bring about glaze
clumping (flocculation), something Na+ ions would do. But H+ ions being
tiny compared to other ions, would not be as effective as Mg++ ions from
Epsom Salts (MgSO4). If you have an option, choose MgSO4.
Tom Buck ) tel: 905-389-2339 (westend Lake Ontario,
province of Ontario, Canada). mailing address: 373 East 43rd Street,
Hamilton ON L8T 3E1 Canada
On Sun, 27 Jun 1999, Carolynn Palmer wrote:
> ----------------------------Original message----------------------------
> A while ago, I asked fellow Clayarters to guess at what a commercial pottery
> was using as a suspension agent (flocculant?) in his glazes and the answers
> were: CMC, Epsom Salts, TriSodium Phosphate and bentonite, among others.
>
> But just recently someone posted about adding muriatic acid to glaze as a
> thickener and wouldn't that also act as a suspension agent?
>
> Carolynn Palmer, Somerset Center, Michigan
>
Michael Banks on wed 30 jun 99
Tom,
In my experience ionic acids, (such as HCl) are more powerful clay
flocculants than salts such as MgSO4 (epsom salts) or CaCl2 (calcium
chloride), another flocculant sometimes used .
There is a theoretical basis for this. Aqueous ionic acids such as
hydrochloric acid (HCl - muriatic acid) are a rich source of H+ ions
(protons). The water hull concept refers to the sheath of water surrounding
a clay particle
within its localised electrical field. The size and nature of this sheath
(in which water molecules have reduced mobility = increased viscosity) is
dependant on the type of cations present in the water. The distance from
the particle that its electrical field becomes zero (at a given
concentration of cations), is governed by the size and charge of the ion.
Clay particles with an overall negative charge repel each other
(deflocculated condition). Close approach of cations to a clay grain with
an overall negative charge results in a flocculated condition. This has
been depicted as opposite charges being concentrated on the faces and edges
of clay plates, resulting in edge/face attraction.
Some ions are small enough to pack in very close (H+ being a clear winner,
being only a proton) to neutralize unsaturated oxygen ions in the clay
lattice, while larger cations - especially of low charge such as K+ are much
less effective. Cations of moderate radii and higher charge such as Mg++
and Ca++ are quite effective. Ionic acids such as hydrochloric acid,
magnesian salts (eg: epsom salt) and calcium salts (eg: calcium chloride)
are strong flocculents. Zn++, Cu++, Fe+++ and Al+++ are also flocculents.
K+, Rb+, NH++++ and Cs+ are intermediate in effect between flocculents and
deflocculents. Na+ and Li+ are mostly deflocculents, but dependant on pH.
This later effect is due to the concentration of those powerful little
protons, as pH is a measure of the concentration of H+ ions.
So the effectiveness of cations to facilitate flocculation of clays is
believed to be due directly to their size and charge at a given
concentration. Protons are so much smaller than Mg++ ions, that the latters
double positive charge fails to overcome the advantage of proximity.
Notwithstanding all this, epsom salts may be preferrable to muriatic acid in
glazes containing nepheline syenite, soda feldspar or other soda-rich
materials such as frits. This is because acids, while initially improving
glaze suspension, eventually attack the soda minerals releasing large surges
of new soluble sodium ions causing even worse settling and "concreting" of
the glaze in the long run. You would have to add more and more acid to
counter the steadily rising pH, until all the neph sy or whatever, is
destroyed.
Acidifying clay bodies in order to improve plasticity is however OK and most
clays have an optimum pH, where plasticity is at a maximum. This optimum is
unique to the specific clay, but is commonly less than pH7, being acidic.
Michael Banks,
Nelson,
New Zealand
> ----------------------------Original message----------------------------
> Muriatic acid is the commecial name for Hydrochloric Acid (HCl), a
> strong mineral acid. In a glaze mix (water + components) the HCl would
> make it harsh on hands, depending on how much is added, other factors.
> The HCl supplies H+ ions and this highly mobile ion would have an
> effect on whether ions from the glaze solids would bring about glaze
> clumping (flocculation), something Na+ ions would do. But H+ ions being
> tiny compared to other ions, would not be as effective as Mg++ ions from
> Epsom Salts (MgSO4). If you have an option, choose MgSO4.
>
> Tom Buck ) tel: 905-389-2339 (westend Lake Ontario,
> province of Ontario, Canada). mailing address: 373 East 43rd Street,
> Hamilton ON L8T 3E1 Canada
Ben Shelton on thu 1 jul 99
Muriatic acid AKA aqua regiae is a combo of hydrochloric and I think
sulphuric acid and is much more acidic than either by themselves
-----Original Message-----
From: Tom Buck
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, June 29, 1999 9:33 AM
Subject: Re: suspension agent for heavily fritted glaze
----------------------------Original message----------------------------
Muriatic acid is the commecial name for Hydrochloric Acid (HCl), a
strong mineral acid. >
Fay & Ralph Loewenthal on fri 2 jul 99
I have not seen Calcium Chloride mentioned, but this is
another pretty good suspension agent. Hope this helps
Ralph in PE SA.
Dave Finkelnburg on fri 2 jul 99
Ben,
As I am sure others will point out, muriatic acid is a solution of
hydrochloric acid, nothing else. Tom is correct. Muriatic acid is the
commonly name frequently used for a relatively dilute hydrochoric acid
solution (usually about 5% HCl) sold to bricklayers. They use it to clean
up mortar off of bricks, because the acid attacks the lime in the mortar.
While concentrated hydrochloric is a very dangerous acid (the fumes are
harmful, the acid can burn you severely) a typical commercial muriatic acid
solution is dilute enough to be less dangerous. I'd still use adequate
protective gear with it, though.
Aqua regia is Latin meaning, literally, "royal water." It is so named
because it is capable of dissolving gold. You are correct that Aqua regia
is a mix of acids. It's made from concentrated nitric and hydrochloric
acids, usually one part of nitric to three parts hydrochloric by volume.
Dave Finkelnburg
dfinkeln@gemstate.net
-----Original Message-----
From: Ben Shelton
To: CLAYART@LSV.UKY.EDU
Date: Thursday, July 01, 1999 3:34 PM
Subject: Re: suspension agent for heavily fritted glaze
>----------------------------Original message----------------------------
>Muriatic acid AKA aqua regiae is a combo of hydrochloric and I think
>sulphuric acid and is much more acidic than either by themselves
>
>
>
>
>
>-----Original Message-----
>From: Tom Buck
>To: CLAYART@LSV.UKY.EDU
>Date: Tuesday, June 29, 1999 9:33 AM
>Subject: Re: suspension agent for heavily fritted glaze
>
>
>----------------------------Original message----------------------------
>Muriatic acid is the commecial name for Hydrochloric Acid (HCl), a
>strong mineral acid. >
>
Edouard Bastarache on sun 4 jul 99
------------------
Hello Dave,
i agree with you that Muriatic Acid is a synonym for Hydrochloric Acid but
the bottle i have in front of me, bought from a local hardware store, has a
label that says:=22Muriatic acid. Contains Hydrochloric Acid 20=25B=E9.
Extremely corrosive.Vapour Harmfull=22.
So best thing to do is to read the label to know what concentration there is
in the bottle.Anything above 5=25 is very harmfull.
I tried it on concrete and it =22boiled=22, so i think at this concentration=
it
is very
toxic to soft tissues, more than on concrete.
Later,
Edouard Bastarache
edouardb=40sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/=7Eedouardb/
-----Message d'origine-----
De : Dave Finkelnburg =3Cdfinkeln=40gemstate.net=3E
=C0 : CLAYART=40LSV.UKY.EDU =3CCLAYART=40LSV.UKY.EDU=3E
Date : 2 juillet, 1999 16:13
Objet : Re: suspension agent for heavily fritted glaze
=3E----------------------------Original message----------------------------
=3EBen,
=3E As I am sure others will point out, muriatic acid is a solution of
=3Ehydrochloric acid, nothing else. Tom is correct. Muriatic acid is the
=3Ecommonly name frequently used for a relatively dilute hydrochoric acid
=3Esolution (usually about 5=25 HCl) sold to bricklayers. They use it to =
clean
=3Eup mortar off of bricks, because the acid attacks the lime in the mortar.
=3EWhile concentrated hydrochloric is a very dangerous acid (the fumes are
=3Eharmful, the acid can burn you severely) a typical commercial muriatic =
acid
=3Esolution is dilute enough to be less dangerous. I'd still use adequate
=3Eprotective gear with it, though.
=3E Aqua regia is Latin meaning, literally, =22royal water.=22 It is so=
named
=3Ebecause it is capable of dissolving gold. You are correct that Aqua =
regia
=3Eis a mix of acids. It's made from concentrated nitric and hydrochloric
=3Eacids, usually one part of nitric to three parts hydrochloric by volume.
=3E Dave Finkelnburg
=3E dfinkeln=40gemstate.net
=3E
=3E
=3E-----Original Message-----
=3EFrom: Ben Shelton =3CBmshelton=40uky.campuscwix.net=3E
=3ETo: CLAYART=40LSV.UKY.EDU =3CCLAYART=40LSV.UKY.EDU=3E
=3EDate: Thursday, July 01, 1999 3:34 PM
=3ESubject: Re: suspension agent for heavily fritted glaze
=3E
=3E
=3E=3E----------------------------Original =
message----------------------------
=3E=3EMuriatic acid AKA aqua regiae is a combo of hydrochloric and I think
=3E=3Esulphuric acid and is much more acidic than either by themselves
=3E=3E
=3E=3E
=3E=3E
=3E=3E
=3E=3E
=3E=3E-----Original Message-----
=3E=3EFrom: Tom Buck =3CTom.Buck=40hwcn.org=3E
=3E=3ETo: CLAYART=40LSV.UKY.EDU =3CCLAYART=40LSV.UKY.EDU=3E
=3E=3EDate: Tuesday, June 29, 1999 9:33 AM
=3E=3ESubject: Re: suspension agent for heavily fritted glaze
=3E=3E
=3E=3E
=3E=3E----------------------------Original =
message----------------------------
=3E=3EMuriatic acid is the commecial name for Hydrochloric Acid (HCl), a
=3E=3Estrong mineral acid. =3E
=3E=3E
| |
|
