Laurie Hashizume on wed 8 jun 11
I have posted various queries previously, and have always had wonderful,
thoughtful responses.... I'm so thankful for this online forum and
members' generosity. I'm back again, now asking for suggestions about
kiln wash.
I'm still a newbie, having had my electric kiln up and running for less
than a year. I use Corelite shelves, firing in oxidation to cone 6.
Since the first firing of my kiln, about 10 months ago, I have tried 3
different kiln wash recipes (including one called "Super no-crack kiln
wash"); all have crackled in the first firing leaving a flaky surface.
If I try to lightly remove a flaky patch to refill it, the edges just
keep flaking to form a progressively larger bare spot. If I try to just
fill in the bare spot, the edges flake and I wind up with chunks of kiln
wash in the new stuff (which winds up flaking in the firing anyway).
The only upside is that it is very easy to scrape the entire shelf clean
and start over .... but having done that repeatedly, it's getting tedious.
I have tried mixing the wash thinner, mixing it thicker, letting it dry
longer (at least 3-4 days before firing), putting on just one coat,
putting on several coats with drying in between - nothing seems to make
a difference.
My question: is there some secret to applying kiln wash, or do I just
need a better recipe? If so, what would those of you with years of
experience recommend?
Thanks!
Laurie Hashizume
William & Susan Schran User on wed 8 jun 11
On 6/8/11 5:04 PM, "Laurie Hashizume" wrote:
> My question: is there some secret to applying kiln wash, or do I just
> need a better recipe? If so, what would those of you with years of
> experience recommend?
Gotta have a clean surface to start with.
I use a simple kiln wash recipe: 1/2 alumina hydrate, 1/2 EPK.
This is by volume, not by weight - one scoop of each, add water mix to heav=
y
cream consistency.
Washing new shelves: wipe with sponge and water, get shelf a little wet.
Apply wash with small, cheap, disposable paint roller.
One coat, one direction, 2nd coat at right angle to first.
Do not paint on edges, clean up cheap paint roller with water to use again.
Coating smaller areas:
Chip off all loose, wash with sponge and water to remove chips/dust.
Paint 2 coats with roller or paint brush.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Lis Allison on wed 8 jun 11
On June 8, 2011, Laurie Hashizume wrote:
> >
> My question: is there some secret to applying kiln wash, or do I just
> need a better recipe? If so, what would those of you with years of
> experience recommend?
>
I recommend not using kiln wash! Unless you intend to really splash glaze
around, you don't need it. Sprinkle some alumina hydrate on the shelves
before putting the ware on them. Just a pinch does the job. You can spread
it around with a large paintbrush if you want (don't do it with fingers or
you may end up with a nasty cut if there is anything on the shelf
already). When you remove the shelves, stack them facr-to-face. Re-use
them the same side up. You don't have to add more every time.
So easy, so quick.....
Lis
--
Elisabeth Allison
Pine Ridge Studio
website: www.pine-ridge.ca
Pottery blog: www.studio-on-the-ridge.blogspot.com
Garden blog: www.garden-on-the-ridge.blogspot.com
=3D?iso-8859-1?B?VGlnIER1cHLp?=3D on thu 9 jun 11
Laurie=3D2C
I've mixed and used just about every kiln wash recipe out=3D20
there=3D2C from the Gator Mud mix I used at the University of=3D20
Florida=3D2C to just spreading fine sand on an unwashed shelf. =3D20
Many worked fine=3D2C many gave me the same problems you're=3D20
experiencing.
I now use the kiln wash from Axner. I don't know the recipe
for this mix=3D2C but I'm pretty sure it has zirconium oxide in it.
I apply it with a paint roller to make a smooth=3D2C even coating=3D2C and
wipe the edges of the shelf with a wet sponge to get up any drips.
Unless there is a catastrophic glaze melt on the shelf=3D2C I don't need to
apply it again for about a year=3D2C if then. It fires hard and doesn't fl=
ak=3D
e. My
porcelain pots don't stick to the shelf=3D2C and any glaze drips are
easily chipped off. I then use a small 1" brush to fill in any divots.
I've also found that it helps to coat the ends of my posts where they sit o=
=3D
n the
shelves to avoid them sticking to the shelf.
This wash has saved me a lot of time and effort=3D2C and I fully recommend
it to you.
<<--------------USUAL COMMERCIAL DISCLAIMER------------------>>
[Fast talker] I have no commercial interest in=3D2C nor any financial backi=
ng
of Axner=3D2C Incorporated of Ovideo=3D2C Florida. This testimony in no wa=
y
constitutes an exclusive endorsement of this product=3D2C nor guarantees
the application of this specific product to the user. Yada=3D2C yada=3D2C y=
ada.=3D
..
<<--------------USUAL COMMERCIAL DISCLAIMER------------------>>
Best of luck with your firings=3D2C
Tig Dupre
in Port Orchard=3D2C WA
=3D
Ron Roy on thu 9 jun 11
Hi Laurie,
I find spraying with a simple pump up hand garden sprayer works well.
What recipes are you using?
RR
Quoting Laurie Hashizume :
> I have posted various queries previously, and have always had wonderful,
> thoughtful responses.... I'm so thankful for this online forum and
> members' generosity. I'm back again, now asking for suggestions about
> kiln wash.
>
> I'm still a newbie, having had my electric kiln up and running for less
> than a year. I use Corelite shelves, firing in oxidation to cone 6.
> Since the first firing of my kiln, about 10 months ago, I have tried 3
> different kiln wash recipes (including one called "Super no-crack kiln
> wash"); all have crackled in the first firing leaving a flaky surface.
> If I try to lightly remove a flaky patch to refill it, the edges just
> keep flaking to form a progressively larger bare spot. If I try to just
> fill in the bare spot, the edges flake and I wind up with chunks of kiln
> wash in the new stuff (which winds up flaking in the firing anyway).
> The only upside is that it is very easy to scrape the entire shelf clean
> and start over .... but having done that repeatedly, it's getting tedious=
.
>
> I have tried mixing the wash thinner, mixing it thicker, letting it dry
> longer (at least 3-4 days before firing), putting on just one coat,
> putting on several coats with drying in between - nothing seems to make
> a difference.
>
> My question: is there some secret to applying kiln wash, or do I just
> need a better recipe? If so, what would those of you with years of
> experience recommend?
>
> Thanks!
>
> Laurie Hashizume
>
Steve Mills on thu 9 jun 11
Dear Laurie,
In your situation I would do what we did for our "Firing Service" kilns.=3D=
20
Sieve Alumina Hydrate powder onto the shelves and comb it even with an old =
h=3D
acksaw blade, wipe the edges a quarter inch in to prevent downward spill, p=
u=3D
t it in the kiln and stack on it. After the firing, tip the Al Hyd onto som=
e=3D
paper and keep it for next time!
Nice and simple.=3D20
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my Ipod touch
On 8 Jun 2011, at 22:04, Laurie Hashizume wrote:
> I have posted various queries previously, and have always had wonderful,
> thoughtful responses.... I'm so thankful for this online forum and
> members' generosity. I'm back again, now asking for suggestions about
> kiln wash.
>=3D20
> I'm still a newbie, having had my electric kiln up and running for less
> than a year. I use Corelite shelves, firing in oxidation to cone 6.
> Since the first firing of my kiln, about 10 months ago, I have tried 3
> different kiln wash recipes (including one called "Super no-crack kiln
> wash"); all have crackled in the first firing leaving a flaky surface.
> If I try to lightly remove a flaky patch to refill it, the edges just
> keep flaking to form a progressively larger bare spot. If I try to just
> fill in the bare spot, the edges flake and I wind up with chunks of kiln
> wash in the new stuff (which winds up flaking in the firing anyway).
> The only upside is that it is very easy to scrape the entire shelf clean
> and start over .... but having done that repeatedly, it's getting tedious=
.=3D
>=3D20
> I have tried mixing the wash thinner, mixing it thicker, letting it dry
> longer (at least 3-4 days before firing), putting on just one coat,
> putting on several coats with drying in between - nothing seems to make
> a difference.
>=3D20
> My question: is there some secret to applying kiln wash, or do I just
> need a better recipe? If so, what would those of you with years of
> experience recommend?
>=3D20
> Thanks!
>=3D20
> Laurie Hashizume
Richard Burkett on fri 10 jun 11
You might find that adding a small amount of deflocculant (sodium silicat=
=3D
e or=3D20
Darvan 7 work) to the wash will minimize the plastic clay shrinkage in th=
=3D
e kiln=3D20
wash and reduce flaking. Use from a few drops to a teaspoon or two for a =
=3D
gallon=3D20
of kiln wash - it's not critical, just don't use a lot. If you make up th=
=3D
e kiln wash a=3D20
bit on the thick side, then add the deflocculant slowly while stirring yo=
=3D
u'll notice=3D20
it getting distinctly thinner and more liquid when you have enough.
Richard Burkett on mon 13 jun 11
Alumina hydrate is usually a finer powder, so it might make it more =3D
likely to raise shrinkage a bit. I've not done any tests specifically =3D
for that.
And if you really want a high-end kiln wash, you could try this recipe =3D
from the earliest days of ClayArt, courtesy of ceramic engineer Karl =3D
Platt, now living in Brazil. You might note below that Karl says that =3D
this kiln wash works for glaze fusing, slumping and casting due to the =3D
zirconium silicate content.
Glaze Name: Karls Killer Kiln Wash
Cone: 010 - 10? (or higher)
Recipe: Pct Amount
EPK 50.00
OM-4 Ball Clay 15.00
Ultrox 20.00 (or use Zircopax)
Flint (325m) 15.00
TOTALS: 100
Also add these colorants and additions:
Bentonite 1.00
CMC 0.30
TSPP or Calgon 0.01
Water 55.00
Comments:
=3D46rom Karl P. Platt on ClayArt listserv on the Internet. TSPP is =3D
tetrasodium pyrophosphate.
Darvan 7 would also work.
Karl's VERY Detailed Notes:
MIXING:
I prefer to mix in a ball mill, in which case I toss in all the =3D
materials and water at once, and mill for 20 minutes.
A blender or high energy stirrer can work also. Here I use the following
procedure:
A. Thoroughly dissolve the CMC and phosphate while agitating the water.
B. Stop stirring and sift the bentonite onto the CMC/H2O solution
C. After the bentonite has thoroughly and naturally wetted and sunk, =3D
stir it in for a bit, say, 5 minutes.
D. Stop agitation and sift OM4 onto the mix and allow it to wet and sink =
=3D
naturally. Wait 5-10 minutes after is has sunk to mix. Mix for 5-10 =3D
minutes.
E. Repeat the above procedure with the EPK.
F.While the clay/water mix is stirring, slowly sift in the Ultrox and =3D
Silica.
This procedure provides a reliable slip. Although the amount of TSPP =3D
will depend on the local water.
Glass, generally speaking, does not stick to this stuff. Some of the =3D
soft
opals, and Bullseye's black, will stick, but the material is easy to
remove. The Wash works best the first time it is used and is spent after =
=3D
2 firings.
On Jun 13, 2011, at 10:40 AM, John Britt wrote:
> That is exactly what I do with the no crack kiln wash.=3D20
>=3D20
>=3D20
> Super Awesome No Crack Kiln Wash=3D20
> 25g. Calcined EPK
> 25g. EPK
> 50g. Alumina=3D20
> 1g. G-200 Feldspar
> Deflocculate to taste (Darvan 7 or sodium silicate)
>=3D20
> Wondering if using alumina hydrate vs alumina (alumina oxide) would =3D
cause cracking?
>=3D20
>=3D20
> johnbrittpottery@gmail.com
>=3D20
>=3D20
John Britt on mon 13 jun 11
That is exactly what I do with the no crack kiln wash.=3D20
Super Awesome No Crack Kiln Wash=3D20
25g. Calcined EPK
25g. EPK
50g. Alumina=3D20
1g. G-200 Feldspar
Deflocculate to taste (Darvan 7 or sodium silicate)
Wondering if using alumina hydrate vs alumina (alumina oxide) would cause=
=3D
cracking?
johnbrittpottery@gmail.com
John Britt on tue 14 jun 11
Thanks for the post Richard.
I don't have a problem with it cracking, just trying to help Laurie, and =
=3D
figure out=3D20
what is wrong.
Johnbritpottery.com
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