Paula Rutledge on sun 27 nov 11
In ceramic glazes, are either Borax (the washing powder) or granular
borax the same chemical as Boric acid? I keep running across glaze
recipes calling for Boric Acid, but I have not been able to find boric ac=
=3D
id
at any ceramic supply store.=3D20=3D20
My college chemistry tells me borax is a sodium tetraborate and boric aci=
=3D
d
is an orthoborate (not necessarily sodium). They are both toxic; they b=
=3D
oth
are boron sources. And granular borax can be anything from sodium borate=
=3D
to
sodium tetra borate dodecahydrate & penthydrate borax depending on w=3D
hether
it is agricultural grade, food grade, industrial grade, fertilizer grade,=
=3D
cosmetic grade...the list goes on and on.=3D20
Do I just use Borax or the granulated borax (in our studio) in place of=
=3D
boric acid in glazes? [I used to be able to buy pure boric acid at the
pharmacy to mix up for pest control; but pharmacies no longer carry it ar=
=3D
e
here.]=3D20=3D20
Thanks for any help.
=3D20
Paula Rutledge
Lee College
Baytown, Texas
William & Susan Schran User on sun 27 nov 11
On 11/27/11 1:05 AM, "Paula Rutledge" wrote:
> My college chemistry tells me borax is a sodium tetraborate and boric aci=
d
> is an orthoborate (not necessarily sodium). They are both toxic; they b=
oth
> are boron sources.
The main difference is the sodium component of the borax. Borax melts at
167F while boric acid melts at 336F. You could probably substitute the bora=
x
for the boric acid but expect the borax to probably cause a lower melting
point of the glaze. Test, test, test.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Steve Slatin on sun 27 nov 11
Boron comes in various natural forms -- Boric acid is H3 B O3.=3DA0 It's=3D=
0Aea=3D
sy to add to a glaze as it's only boron plus things that are lost in igniti=
=3D
on,=3D0Aso you can readily calculate how much actual boron you're adding in=
.=3D
=3DA0=3D0ABorax is Na2 B4 O7 (10 H2O) so in addition to the water (which is=
=3D0Al=3D
ost in ignition) and the Oxygen (ditto) it adds sodium to the glaze.=3DA0 Y=
ou=3D
=3D0Ahave to calculate for that if you are substituting borax for boric aci=
d =3D
in=3D0Aa recipe.=3DA0 But if you're ready to do the substitution,=3DA0 sinc=
e=3D0A=3D
=3DA0=3D0AAFAIK, granulated borax is just a different grade of borax, and s=
houl=3D
d=3D0Abe much the same chemically.=3D0A=3D0ASteve Slatin -- =3D0A=3D0A=3D0A=
N48.0886450=3D
=3D0AW123.1420482=3D0A=3D0A=3D0A________________________________=3D0A=3D0AI=
n ceramic gl=3D
azes,=3DA0 are either=3DA0 Borax (the washing powder) or=3DA0 granular=3D0A=
borax=3DA0=3D
the same chemical=3DA0 as Boric acid?=3DA0 I keep running across glaze=3D0=
Arecip=3D
es calling for Boric Acid, but I have not been able to find boric acid=3D0A=
at=3D
any ceramic supply store.=3DA0 =3D0AMy college chemistry tells me borax is=
a s=3D
odium tetraborate and boric acid=3D0Ais an orthoborate=3DA0 (not necessaril=
y so=3D
dium).=3DA0 They are both toxic; they both=3D0Aare boron sources.=3DA0 And =
granul=3D
ar borax can be anything from sodium borate to=3D0Asodium tetra borate dode=
ca=3D
hydrate & penthydrate borax=3DA0 depending on whether=3D0Ait is agricultura=
l gr=3D
ade, food grade, industrial grade, fertilizer grade,=3D0Acosmetic grade...t=
he=3D
list goes on and on. =3D0ADo I just use Borax=3DA0 or the granulated borax=
(in=3D
our studio)=3DA0 in place of=3D0Aboric acid in glazes?=3DA0 [I used to be =
able t=3D
o buy pure boric acid at the=3D0Apharmacy to mix up for pest control; but p=
ha=3D
rmacies no longer carry it are=3D0Ahere.]=3DA0 =3D0AThanks for any help.=3D=
0A=3D0APau=3D
la Rutledge=3D0ALee College=3D0ABaytown, Texas=3D0A=3D0A=3D0A=3D0Ayou had s=
ome chemistr=3D
y, the process, while tedious, should be fairly=3D0Aeasy.
Edouard Bastarache on sun 27 nov 11
Check this also :
http://smart2000.pagesperso-orange.fr/bore.htm
in French and English,,,
Gis,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://edouardbastaracheblogs2.blogspot.com/
http://www.facebook.com/edouard.bastarache
----- Original Message -----
From: "Steve Slatin"
To:
Sent: Sunday, November 27, 2011 10:56 AM
Subject: Re: Boric Acid question
Boron comes in various natural forms -- Boric acid is H3 B O3. It's
easy to add to a glaze as it's only boron plus things that are lost in
ignition,
so you can readily calculate how much actual boron you're adding in.
Borax is Na2 B4 O7 (10 H2O) so in addition to the water (which is
lost in ignition) and the Oxygen (ditto) it adds sodium to the glaze. You
have to calculate for that if you are substituting borax for boric acid in
a recipe. But if you're ready to do the substitution, since
AFAIK, granulated borax is just a different grade of borax, and should
be much the same chemically.
Steve Slatin --
N48.0886450
W123.1420482
________________________________
In ceramic glazes, are either Borax (the washing powder) or granular
borax the same chemical as Boric acid? I keep running across glaze
recipes calling for Boric Acid, but I have not been able to find boric acid
at any ceramic supply store.
My college chemistry tells me borax is a sodium tetraborate and boric acid
is an orthoborate (not necessarily sodium). They are both toxic; they both
are boron sources. And granular borax can be anything from sodium borate to
sodium tetra borate dodecahydrate & penthydrate borax depending on whether
it is agricultural grade, food grade, industrial grade, fertilizer grade,
cosmetic grade...the list goes on and on.
Do I just use Borax or the granulated borax (in our studio) in place of
boric acid in glazes? [I used to be able to buy pure boric acid at the
pharmacy to mix up for pest control; but pharmacies no longer carry it are
here.]
Thanks for any help.
Paula Rutledge
Lee College
Baytown, Texas
you had some chemistry, the process, while tedious, should be fairly
easy.
Snail Scott on sun 27 nov 11
Boric acid is sold as a non-poisonous bug killer -
try a garden center or hardware store. Not sure of
the purity, but you'd be testing it anyway, right?
-Snail
jonathan byler on mon 28 nov 11
Please be careful saying things like "boric acid is toxic." in large
enough doses, yes, it can be toxic. it has about the same LD50 rate
as table salt, however - about 3/4 lb for a 150lb human is considered
a toxic dose. Not sure how you would manage to consume that much of
the stuff. I have a feeling it doesn't taste very good. When was the
last time you consumed 3/4lb of table salt in a sitting? Boric acid
is also sometimes used in eye washes due to it's anti-bacterial
qualities. I don't think I would do that unless under medical
supervision, but I know folks who have and lived to tell about it.
Water is toxic if you drink enough of it. everything is toxic in high
enough doses. But we don't want to scare folks into using nothing.
Know the risks and the facts before you label something toxic in a
public forum.
As far as procuring the stuff, there are online sources for boric
acid, including various DIY pest control sites. For random chemicals
that I can't easily find locally, I like to do business with the fine
folks a U.S. Pigments. Others on clayart have also had positive
dealings with them, and I find they have competitive pricing on just
about everything they sell. YMMV.
On Nov 27, 2011, at 12:05 AM, Paula Rutledge wrote:
> In ceramic glazes, are either Borax (the washing powder) or
> granular
> borax the same chemical as Boric acid? I keep running across glaze
> recipes calling for Boric Acid, but I have not been able to find
> boric acid
> at any ceramic supply store.
> My college chemistry tells me borax is a sodium tetraborate and
> boric acid
> is an orthoborate (not necessarily sodium). They are both toxic;
> they both
> are boron sources. And granular borax can be anything from sodium
> borate to
> sodium tetra borate dodecahydrate & penthydrate borax depending on
> whether
> it is agricultural grade, food grade, industrial grade, fertilizer
> grade,
> cosmetic grade...the list goes on and on.
> Do I just use Borax or the granulated borax (in our studio) in
> place of
> boric acid in glazes? [I used to be able to buy pure boric acid at
> the
> pharmacy to mix up for pest control; but pharmacies no longer carry
> it are
> here.]
> Thanks for any help.
>
> Paula Rutledge
> Lee College
> Baytown, Texas
ivor and olive lewis on tue 29 nov 11
Dear Paula Rutledge,
Boric acid can be obtained from any good, well stocked Pharmacy.
Ask for Boracic Acid. From memory I recall that it is a water soluble glass=
,
not a crystalline compound.
Regards,
Ivor Lewis,
REDHILL,
South Australia
Barro Cocido on tue 29 nov 11
http://www.walgreens.com/store/c/pic-boric-acid-roach-killer-iii-powder/I=
=3D
D=3D3Dprod3997-product
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