Janet or Michael Francoeur on fri 25 apr 97
Sure could use some help. We are using Amaco majolica glazes. I brush on
3 coats of the white base & paint my design on with 1 coat of their colored
glaze. The base coat has pits, like a bubble broke & exposes the red
clay below, also my colors are very washed out. I have done lots of tiles
with their underglazes & don't hae any problems but you have to apply 2 or
3 coats of it to cover. Makes it kind of hard to be free in your brush work
not even considering the time it takes.
We are using Brooklyn Red from Highwater, bisque at 04, glaze fire at 4.
Appreciate any thoughts
Janet Francoeur
michael@cconnect.net
Paul and C2 on sun 27 apr 97
>----------------------------Original message----------------------------
>
Dear Janet,
I think majolica glazes does not go up to cone 4. Bubbling like that
sounds like you've overfired your glazes!
Caroline
>
>Sure could use some help. We are using Amaco majolica glazes. I brush on
>3 coats of the white base & paint my design on with 1 coat of their colored
>glaze. The base coat has pits, like a bubble broke & exposes the red
>clay below, also my colors are very washed out. I have done lots of tiles
>with their underglazes & don't hae any problems but you have to apply 2 or
>3 coats of it to cover. Makes it kind of hard to be free in your brush work
>not even considering the time it takes.
>
>We are using Brooklyn Red from Highwater, bisque at 04, glaze fire at 4.
>
>Appreciate any thoughts
>Janet Francoeur
>michael@cconnect.net
Helen Crowe on sat 20 jun 98
I fire to 04 and use Matthias majolica recipe (3124, flint, ball clay,
china clay and tin). My stains are mixed one tsp. stain to 1 tsp 3124 frit.
I am firing Johnson bisqued tiles. My problem is that the stains break up
on the surface. The glaze melts beautifully but a lot of the surface,
although smooth looks like death valley dried mud. Unsightly. Does anyone
know what I mean. Can anyone help? I try not to apply the stains too
thickly. helen
Gay Judson on tue 14 sep 10
I'm working with majolica on earthenware and having some problems I =3D
can't sort out. On the majolica white glaze I am painting designs with =3D
'paints' made of Mason stains and frit 3124. In some cases I paint a =3D
color wash over all. The problem is that I am getting white speckles =3D
coming up through the colors. But not always. On a set of 6 small =3D
plates the white speckles came up through the green bamboo on 5 of the 6 =
=3D
plates--the 6th came out just as painted with no speckles. On two bowls =
=3D
(not a set) both glazed with the white majolica and then brushed over =3D
with a colored wash. On one the speckles came up through the wash =3D
(blue) but not any on the other (yellow wash). Any idea what is =3D
happening--and more important, how I can control it?
Thanks for any help!
Gay Judson in San Antonio=3D
Lili Krakowski on tue 14 sep 10
Gail writes: ... On the majolica white glaze I am painting designs with
'paints' made of Mason stains and frit 3124. In some cases I paint a color
wash over all. The problem is that I am getting white speckles coming up
through the colors. . On two bowls (not a set) both glazed with the white
majolica and then brushed over with a colored wash. On one the speckles cam=
e
up through the wash (blue) but not any on the other (yellow wash). Any idea
what is happening--
Years ago a student of mine and that problem--and we traced it back to talc
in the body. I regret to say that it was something akin to asbestos in the
clay that somehow was not "digested" well in the mix...it was so long ago
I forget the details.
However. I seriously suspect the body. Something in it.
Possible "cures":
1. Call the clay manufacturer, ask if others have complained of same
problem....2.Dry some of the body, return it to slip, strain slip through
very fine mesh. Seem if anything remains in sieve. Make test tiles of
resulting clay...see what gives. 3. Test your glaze and process on another
body or two.
(This is why I keep "insisting" one always have (or can mix) two or three
other bodies, similar to one's primary one, to test this kind of stuff.)
Lettuce know.
Lili Krakowski
Be of good courage
Neon-Cat on sun 19 sep 10
Hi Gay,
sorry to read that you're getting white speckles using 3124 plus
stains. You might try less 3124 for the problem 'paints' or mix a bit
of EPK with the 3124 (9/91, respectively). By themselves some of the
calcium borosilicate frits will look opaque (whitish, not clear)
although they melt at low kiln temperatures. What you are seeing is
probably small agglomerations of the frit itself. For example, for pit
firing if I want a shiny white splash on a pot I'll apply a paste of
pure P-25. The 3124 works great as a colorant aid at higher temps but
for earthenware you might want to try something different.
Alternately, sieving your 'paint' well (100 mesh or finer) before each
use might help. For me, I like a wee pinch of CMC or boric acid for
low temp. work with stains or oxides but I have not used them over
majolica -- that might be just horrible for you.
Good luck! I'd like to see some of your pretty finished work.
Marian
neoncat
sharonia628 on mon 20 sep 10
Re; white spotting, in addition to what's been offered here, I've found tha=
t
overwetting the majolica glaze with the pigments can cause this. In other
words, it truly is a one brush stroke deal.
Sharon
--
Sharon La Rocca Miranda
sharonmiranda.com
Bonnie Staffel on tue 21 sep 10
> Re; white spotting, in addition to what's been offered here, I've =3D
found
that overwetting the majolica glaze with the pigments can cause this. In
other words, it truly is a one brush stroke deal.>
Following this line of thinking as a solution to the problem, I also =3D
found
that if I loaded the kiln before the decorated pot was dry, that the =3D
white
spotting occurred. After that deduction, I left the decorated pot to dry
thoroughly before firing and the problem stopped. I often sprayed the =3D
colors
for the background and/or did the one brush stroke to apply a wash. My
thought was that it was steam coming from the bisque base causing =3D
boiling
action from the white glaze below. I fire to Cone 9 regularly.=3D20
Bonnie Staffel
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
DVD=3DA0 Throwing with Coils and Slabs
DVD=3DA0 Introduction to Wheel Work
Charter Member Potters Council
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