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raku resist slip

updated sun 9 jun 02

 

Dan Johnston on sat 22 mar 97

Hey everyone:

I'm looking for a good Raku resist slip that will give a good smoke
pattern and then come off easily after firing. Does anyone have a good
recipe to share?

Dan Johnston
Farmington MO
danj@ldd.net

Darrol F. Shillingburg on mon 24 mar 97

Hi Dan,

Wish I did! I have been looking for something to do the same trick. So far I
have had limited success using a cone 5 porcelain slip mixed with 25% to 50%
kiln wash.

Problem is that the slip/kiln wash combo is porous enough to allow some
carbonizing underneath darkening the colored clay that I was trying to mask. Not
enough kiln wash and the mask becomes the piece. The problem is getting a
nonporous slip mask that comes off when you want it to.

The possibilities in the technique are so intreiging that I will continue to
experiment, but sure wish someone had a ready answer.

Darrol in Elephant Butte, NM

Neupet@aol.com on mon 24 mar 97

Dan,

I've gathered a lot of these with the help of Clayart; all but one use glaze
as well. Here's the list:

Shadow Slip

Fire Clay 50
EPK 30
Alumina Hydrate 20

Leaves pattern

Reducing Alumina to 10% makes it easier to remove No glaze is used. To make
this stuff stick I terra sig and burnish the pot, wet it, then pour on this
stuff thick and gloppy. It's hard to prevent some from falling off but
removal is easy at the end. And, from Clayart, this information:

NAKED RAKU
Resist Slips and Glazes To Go With Them

David Roberts resist slip
(EPK)Kaolin 3 parts by volume
Flint 2 parts by volume
Copper Oxide 10% (or none)

use with the following glaze
Raku Crackle Glaze
(by David Roberts in Sawdust Firing)
High Alkali Frit 45%
Soft Borax Frit 45%
China Clay 10%

Fire to 1562-1652F.

Glaze Marie-Claire in the Netherlands
90% Borax frit
10% kaolin
____________________________________________________
Resist Slip Marie-Claire
2 parts kaolin
3 parts flint or silica

works with

Glaze
Frit 3110 65%
Gerstley Borate 35%

don't use this glaze with the Roberts slip
__________________________________________________
Jacobsons' Slip and Glaze
Slip
40% Lincoln 60 fireclay
30% 6-Tile clay
20% Ione 412 Grog
10% Custer feldspar

Glaze
60% Ferro Frit 3110
40% Gerstley Borate

Bisque to Cone 012-010
Fire to cone 014, smoke, water-quench, peel
___________________________________________________________

Marci Masterson
(From Sharon in Fort Worth)
#1
Fire Clay 40 grams
#6 Tile 30 grams
Custer 10 grams
Grog (28 mesh) 20 grams

#3
Fire Clay 50 grams
EPK 40 grams
Soda Spar 10 grams
(Add 5 - 15% grog)

#4
Fire Clay 50 grams
EPK 35 grams
Nepheline Syenite 15 grams
(add 5% grog - no more)

#5
Fire Clay 45 grams
EPK 35 grams
Flint 10 grams
Nepheline Syenite 10 grams
(add 5% Grog - no more)

Notes:
(can't find #2)
#1. If fire clay is gritty, don't need grog (or need less grog).
Interesting small
design w/o grog. Marcie uses 10% grog. Apply one thinned coat crubbed.
Removes very
easily.

#3. Similar to #1. Marcie uses 10% grog.

#4. Semi straight edge design. Applies 4 even coats. Thinner and smaller
design.
Removed easily.

#5. Fairly straight edge design (almost geometric). Hard to remove. Apply
like #4.
Used w/o grog is good but small.

Additional notes: Every thing with talc "fused". Try other fluxes; try
other clays.
Almost all recipes will work with 25-50% raku claybody w/grog or sand. Mix
slip to a
consistency where it will just "pour" not "plop" off a spoon.

The following is the glaze recipe which is applied over the slip:

70% Ferro Frit 3110
30% Gerstly Borate

Mix "milk" thin and apply thinly.

This should give you some tests to work on.

Lynne Berman in cold and sunny Philadelphia where we are looking forward to
raku season

Tadeusz Westawic on tue 25 mar 97

Hi All,

I've been messing with slip resists in raku for about a year and a half.
For those of you who don't know, slip resist is a raku technique where a
bisque pot is coated with slip and fired and reduced in the normal
fashion. During or after cooling, the slip comes off the pot. On a white
firing body, the result is a "crackle" pattern without the glaze. The
slip shrinks during firing and develops shrink cracks, then during post
firing reduction (pfr), carbonisation takes place through the cracks in
the slip but not (hopefully) through the slip itself. Slip generally
does not craze in exactly the same general patterns as glazes, and some
of the resulting "smoke" patterns are very attractive.

I've been able to turn-out good small pots about 80% of the time, good
medium pots about 60% or the time, and good large pots about 40% of the
time. Those figures are not adjusted for pots that are bad due to lousy
surface composition and balance (ie my fault). The major problem, as
Lynne Berman pointed-out, is keeping the slip on the pot through the
firing cycle, or getting it off the pot after the firing cycle. The
other major problem is getting a slip which effectively resists the
carbonisation. Many, many pots come-out much too dark.

I would like to share some of my observations:

For any slip formula I have tried that worked, it also didn't work. That
is, sometimes it worked and sometimes it didn't. Lately, I am thinking
that heating schedule and dryness of slip play a larger part in success
than one might think, perhaps a larger part than the slip formula
itself. A thicker slip can go into the kiln wetter than a thin coat. A
thin coat can be heated faster than a thick coat.

Even heating is a must if experimenting. Electric is ideal, but that's
not to say that gas will not work. You just have to keep the heat as
uniform as possible in the early stages so that the slip doesn't shrink
too fast on one side of the pot and fall off. Some standing hard brick
ballast in a gas kiln might help here. I use electrics myself.

I tried to improve the reduction resistance of my slips by going to
finer particle size in the slip. I tried differnt clays and such (no
fluxes) with poor results. I eventually discovered that a thin coat on
the slip itself of something fusible increased the reduction resistance
markedly. So one might try holding the flux out of the slip mix but
spray it on right after slip application. The idea is to flux just the
surface of the slip and not the area adherent to the pot. Soda ash is
very effective, but it fumes in the kiln, gets to places on the pot
where it ain't supposed to be, and gets on the walls of the kiln and
influences subsequent firings.

The "texture" of the resulting smoke pattern can be graduated coarser by
bisquing a first coat of slip, slow cooling, then applying a secod coat
where you want a coarser texture. I have done this up to four coats of a
just plain fireclay slip with good results. One needs a raku body that
will withstand the multiple firings.


Okay, that's some of what I think I know. If any of you raku folk are
also trying to develop this promising technique, please share. I would
like to hear from you personally or in this Clayart forum.

Tadzu -- picking and shoveling New Mexico granite, making way for studio
expansion.

Wendy Hampton on wed 26 mar 97

Hi Darryl,
There was an article in Ceramics Monthly about 2 years ago that gave a great
recipe for the slip you are looking for. The people who use it were Kate and
Will Jacobson. Good luck in finding it.
Wendy from Bainbridge Island WA

"Rafael Molina-Rodriguez (Rafael Molina-Rodriguez)" on thu 27 mar 97

Wendy :

The following slip/glaze information is from the article "Freedom to
Discover" by Will and Kate Jacobson in the February 1992 Ceramics
Monthly :

"After a cone 012 - 010 bisque firing, each pot is covered with slip made
from 40 % Lincoln 60 fireclay, 30 % 6-Tile clay, 20 % Ione 412 grog and
10 % Custer feldspar; then glazed with a mixture of 60 % Ferro frit 3110
and 40 % Gerstley borate; fired to cone 014; smoked; water quenched;
and peeled."

Good luck!

Rafael

>>> Wendy Hampton 03/26/97 07:43am >>>
----------------------------Original message----------------------------
Hi Darryl,
There was an article in Ceramics Monthly about 2 years ago that gave a
great
recipe for the slip you are looking for. The people who use it were Kate
and
Will Jacobson. Good luck in finding it.
Wendy from Bainbridge Island WA

william schran on fri 7 jun 02


Vicki - Have had good luck with 3 parts EPK & 2 parts silica. Apply
THIN coat of glaze and remove from kiln when you see the glaze
bubbling and before final melt.
Bill

Bruce Girrell on fri 7 jun 02


> Help! I have tried many recipes for a resist slip to use
> under 80/20 white
> crackle. i can't get any of thyem to peel off.

Please tell me how you're doing it. I can't get any of mine to stay _on_ the
pot.


Bruce "let's get naked (raku)" Girrell

L. P. Skeen on fri 7 jun 02


If you are trying to do naked raku, the whole point is that there is NO
glaze of any kind on the piece - hence the name NAKED. If you are putting a
glaze over the resist slip, you are defeating the purpose and effectively
gluing the slip chunks onto your pot.

Either use glaze and reduce as usual, then remove from reduction can and
spritz w/ water to get a crackle, OR use a resist slip and scrape it off
after it cools in the reduction can. Either, OR, not both.

L
----- Original Message -----
From: "Vicki Conley"
To:
Sent: Wednesday, June 05, 2002 1:25 PM
Subject: Raku resist slip


> Help! I have tried many recipes for a resist slip to use under
80/20 white
> crackle. i can't get any of thyem to peel off. Does anyone have a good
> technique and recipe to share? Also how hot do you fire to? I have been
> firing to about 1860 and the last load was to 1800. Maybe it is too hot
and
> the slip is maturing. Any suggestions would be appreciated. Vicki
>
> Vicki Conley
> vicki@pinonpottery.com
> www.pinonpottery.com
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>

Megan Ratchford on fri 7 jun 02


Hi Vicki! I use a cone 04 slip mixed to the consistency of yogurt. Any
slip recipie will do. I've found that ball clay works pretty well if
blended smooth. I "glop" it on very thick and fire to cone 010. If it's
not peeling off it could be:
1. Fired too hot
2. Applied too thin
3. Under a glaze that has filled the cracks and is holding it together.
You did mention something about using it under a white crackle? When I do
this I use no glaze and just let the smoke resist show off on its own.
Also, if your piece is very, very smooth it will also help.
Megan
----- Original Message -----
From: "Vicki Conley"
To:
Sent: Wednesday, June 05, 2002 11:25 AM
Subject: Raku resist slip


> Help! I have tried many recipes for a resist slip to use under
80/20 white
> crackle. i can't get any of thyem to peel off. Does anyone have a good
> technique and recipe to share? Also how hot do you fire to? I have been
> firing to about 1860 and the last load was to 1800. Maybe it is too hot
and
> the slip is maturing. Any suggestions would be appreciated. Vicki
>
> Vicki Conley
> vicki@pinonpottery.com
> www.pinonpottery.com
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.

Charles and Linda Riggs on sat 8 jun 02


Hi Vickie,

I found all these recipes in some old Clayart files. Have fun
experimenting.

Linda Riggs


NAKED RAKU
Resist Slips and Glazes To Go With Them

David Roberts resist slip
(EPK)Kaolin 3 parts by volume
Flint 2 parts by volume
Copper Oxide 10% (or none)

use with the following glaze
Raku Crackle Glaze
(by David Roberts in Sawdust Firing)
High Alkali Frit 45%
Soft Borax Frit 45%
China Clay 10%

Fire to 1562-1652F.

Glaze Marie-Claire in the Netherlands
90% Borax frit
10% kaolin
____________________________________________________
Resist Slip Marie-Claire
2 parts kaolin
3 parts flint or silica

works with

Glaze
Frit 3110 65%
Gerstley Borate 35%

don't use this glaze with the Roberts slip
__________________________________________________
Jacobsons' Slip and Glaze
Slip
40% Lincoln 60 fireclay
30% 6-Tile clay
20% Ione 412 Grog
10% Custer feldspar

or this variation used without glaze

Chip n Slip
40% Hawthrone Bone or A-P Fireclay
30% Kaolin
20% Pyrotol (or grog)
10% Custer Feldspar


Glaze
60% Ferro Frit 3110
40% Gerstley Borate

Bisque to Cone 012-010
Fire to cone 014 (1540F.), smoke, water-quench, peel
___________________________________________________________
Gordon Hutchens Slip
used without glaze

Fire Clay 50
EPK 30
Alumina Hydrate 20 (or 10% for easier removal)




Marci Masterson
(From Sharon in Fort Worth)
#1
Fire Clay 40 grams
#6 Tile 30 grams
Custer 10 grams
Grog (28 mesh) 20 grams

#3
Fire Clay 50 grams
EPK 40 grams
Soda Spar 10 grams
(Add 5 - 15% grog)

#4
Fire Clay 50 grams
EPK 35 grams
Nepheline Syenite 15 grams
(add 5% grog - no more)

#5
Fire Clay 45 grams
EPK 35 grams
Flint 10 grams
Nepheline Syenite 10 grams
(add 5% Grog - no more)

Notes:
(can't find #2)
#1. If fire clay is gritty, don't need grog (or need less grog).
Interesting small
design w/o grog. Marcie uses 10% grog. Apply one thinned coat
crubbed.
Removes very
easily.

#3. Similar to #1. Marcie uses 10% grog.

#4. Semi straight edge design. Applies 4 even coats. Thinner
and smaller
design.
Removed easily.

#5. Fairly straight edge design (almost geometric). Hard to
remove. Apply
like #4.
Used w/o grog is good but small.

Additional notes: Every thing with talc "fused". Try other
fluxes; try
other clays.
Almost all recipes will work with 25-50% raku claybody w/grog or
sand. Mix
slip to a
consistency where it will just "pour" not "plop" off a spoon.

The following is the glaze recipe which is applied over the slip:

70% Ferro Frit 3110
30% Gerstly Borate

Mix "milk" thin and apply thinly.

islandplace on sat 8 jun 02


Yahoo has a group that deals specifically with this subject:
www.groups.yahoo.com/group/nakedraku

----- Original Message -----
From: "Vicki Conley"
To:
Sent: Wednesday, June 05, 2002 1:25 PM
Subject: Raku resist slip


> Help! I have tried many recipes for a resist slip to use under
80/20 white
> crackle. i can't get any of thyem to peel off. Does anyone have a good
> technique and recipe to share? Also how hot do you fire to? I have been
> firing to about 1860 and the last load was to 1800. Maybe it is too hot
and
> the slip is maturing. Any suggestions would be appreciated. Vicki
>
> Vicki Conley
> vicki@pinonpottery.com
> www.pinonpottery.com
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>

Kim Peterson on mon 10 jun 02


I must say that Megan's "naked" raku is beautiful, and her method works.
Another option is to bruch the slip in one direction. This tends to make the
slip crack along the brush lines. A unique effect..
Kim



>From: Megan Ratchford
>Reply-To: Megan Ratchford
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: Raku resist slip
>Date: Fri, 7 Jun 2002 20:14:29 -0600
>
>Hi Vicki! I use a cone 04 slip mixed to the consistency of yogurt. Any
>slip recipie will do. I've found that ball clay works pretty well if
>blended smooth. I "glop" it on very thick and fire to cone 010. If it's
>not peeling off it could be:
> 1. Fired too hot
> 2. Applied too thin
> 3. Under a glaze that has filled the cracks and is holding it
>together.
>You did mention something about using it under a white crackle? When I do
>this I use no glaze and just let the smoke resist show off on its own.
> Also, if your piece is very, very smooth it will also help.
>Megan
>----- Original Message -----
>From: "Vicki Conley"
>To:
>Sent: Wednesday, June 05, 2002 11:25 AM
>Subject: Raku resist slip
>
>
> > Help! I have tried many recipes for a resist slip to use under
>80/20 white
> > crackle. i can't get any of thyem to peel off. Does anyone have a good
> > technique and recipe to share? Also how hot do you fire to? I have been
> > firing to about 1860 and the last load was to 1800. Maybe it is too hot
>and
> > the slip is maturing. Any suggestions would be appreciated. Vicki
> >
> > Vicki Conley
> > vicki@pinonpottery.com
> > www.pinonpottery.com
> >
> >
>___________________________________________________________________________
_
>__
> > Send postings to clayart@lsv.ceramics.org
> >
> > You may look at the archives for the list or change your subscription
> > settings from http://www.ceramics.org/clayart/
> >
> > Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
>
>___________________________________________________________________________
___
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.




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