Kenneth J. Nowicki on tue 25 nov 03
Hello Ellen,
I would tend to think that at 1850 degrees Fahrenheit, any wax resist that is
out there on the market would be vaporized and completely melted away, so I
don't suspect that the wax resist is the cause of the problem you are
describing. Anyone else can certainly chime in here with their thoughts...?
I don't know just how deep of black you are trying to get... or expecting...
but in my experience the combustible materials used in the PFR (post-fired
reduction) combined with the heat of the actual pot when it's placed in the
reduction can has more to do with the degree of carbon staining the unglazed areas
than the wax resist does. (What I mean by the "actual heat of the pot" is how
hot you are firing to when you remove the pot, how long the cool air touches
the pot before putting in PFR, if you "burp" your lids during PFR and allow the
materials to re-ignite and if so... how often, etc.) For my combustibles,
most of the time I use sawdust and shredded newspaper.
I use the standard liquid wax resist sold by Laguna Clay and have had no
problem achieving decent blacks in the unglazed areas. However, I think if you're
looking for a really "jet black"... like you see when you're pot is wet and
you're scrubbing off all of the carbonaceous materials... you'd probably be
better off considering spraying your finished work with a clear coat of some type
of sealer... perhaps a polyurethane sealant of some sort... this should darken
those dark charcoal grays into a deeper black I would think. Experiment and
find out... and please get back to us and let us know what your results are.
If you would like to see an example of the blacks I achieve that are typical
of my wax resist designs on my raku vessels, cut and paste this into your
browser:
http://thewallintheartistscafe.com/cgi-bin/artwork/member.pl?artist46&&UserID
There is one other variable that might play into this discussion, and that
could be the temperature of your bisque you are firing to. It may be possible
that if you are firing too hot, that the clay body might not be as receptive to
absorbing the carbon smoke than if you fired a little lower. I'm just tossing
ideas out to think about here. I'm not certain how much this would be a
factor, but seems logical to me. I usually bisque to around cone 06.
Thanks for bringing up a good topic for discussion. I'd like to hear others
thoughts on this... anyone?
Warm holiday wishes everyone!
Ken
"celebrating my 45th birthday this week and feeling better than ever, despite
having been recently diagnosed with adult-onset diabetes (type II)... in one
month of being on a low-carb diet... I've lost 10 pounds... dropped my blood
sugar dramatically from "bad" to "excellent"... and gone from a size 52 jacket
to size 48!!! Life is good! :-)"
Kenneth J. Nowicki
Port Washington, NY
RakuArtist@aol.com
...................................................................
> ellen (e2002meyer@EARTHLINK.NET) wrote:
> A question for the raku guru's........
>
> I want to keep the rich blacks on the unglazed areas and have found that
> wax resist actually penetrates the bisque. The areas where I used the wax
> do not come out rich black after reduction, they are more of a dark
> charcoal grey. We are firing to 1850 and getting great blacks except
> where the wax was and it is noticeable.
>
> Is anyone using a paintable resist, that will burn away 100% in the
> firing, and allow the blacks to be the same as the virgin bisqued area???
> I am going to try rubber cement....... Any other ideas???
Susan Setley on tue 25 nov 03
In a message dated 11/25/03 10:09:53 AM, RakuArtist@AOL.COM writes:
<< Hello Ellen,
I would tend to think that at 1850 degrees Fahrenheit, any wax resist that is
out there on the market would be vaporized and completely melted away, so I
don't suspect that the wax resist is the cause of the problem you are
describing. Anyone else can certainly chime in here with their thoughts...? >>
We have not had the problem of wax resist preventing good blackening. What we
have found is that some combustibles are MUCH better than others.
One young man in my class works in an office that shreds a LOT of documents.
He brings in bags of high-quality printer paper every week, shredded very
thin. We have found that this paper provides a lot more "black" than newspaper
does and is less likely to leave marks on the piece. I tend to use sawdust but I
always include some of his paper. The results of my firings have improved
markedly.
Our teacher suspects that the change is because newspapers now use soy-based
ink instead of lead-based ink. Obviously for the environment's sake they
needed to make that change, but I think the poster might experiment with different
combustibles.
daniel on tue 25 nov 03
Hi Ken, Ellen,
On the wax. I wax the base of cone 10 reduction stuff a bit and on occasion
I'd swear you can see where it was when its fired - prob only on a white
stoneware come to think of it. I'll go look at some pieces tonight and
report back if I was hallucinating or not.
On the deep blacks question I've been terra sig'ing the pots before
raku'ing lately. If you polish it up a bit with a cloth (insufficient
patience for real burnishing) it'll go nice and shiny. Flambe it. Then drop
it in a can and it'll go deep black if you have a tight lid and lots a
smoke. I get good contrasts with say a copper luster or a copper matte this
way. If you don't polish you get a nice matte.
On the clear finish thing. I just tried an acryllic (just as an experiment
to solve a different problem) and I can't say I'm happy with it. It glossed
it up big time (but then it was a gloss). I also have polyurethane and will
try it next on another test piece. Incidentally the acryllic also took the
shine off the copper luster. The light is not getting to it the way it did.
I already had sig on the pot and though it may have darkened a fraction I
wouldn't swear to it.
Thanx
D
Kenneth J. Nowicki writes:
> Hello Ellen,
>
> I would tend to think that at 1850 degrees Fahrenheit, any wax resist that is
> out there on the market would be vaporized and completely melted away, so I
> don't suspect that the wax resist is the cause of the problem you are
> describing. Anyone else can certainly chime in here with their thoughts...?
>
> I don't know just how deep of black you are trying to get... or expecting...
> but in my experience the combustible materials used in the PFR (post-fired
> reduction) combined with the heat of the actual pot when it's placed in the
> reduction can has more to do with the degree of carbon staining the unglazed areas
> than the wax resist does. (What I mean by the "actual heat of the pot" is how
> hot you are firing to when you remove the pot, how long the cool air touches
> the pot before putting in PFR, if you "burp" your lids during PFR and allow the
> materials to re-ignite and if so... how often, etc.) For my combustibles,
> most of the time I use sawdust and shredded newspaper.
>
> I use the standard liquid wax resist sold by Laguna Clay and have had no
> problem achieving decent blacks in the unglazed areas. However, I think if you're
> looking for a really "jet black"... like you see when you're pot is wet and
> you're scrubbing off all of the carbonaceous materials... you'd probably be
> better off considering spraying your finished work with a clear coat of some type
> of sealer... perhaps a polyurethane sealant of some sort... this should darken
> those dark charcoal grays into a deeper black I would think. Experiment and
> find out... and please get back to us and let us know what your results are.
>
> If you would like to see an example of the blacks I achieve that are typical
> of my wax resist designs on my raku vessels, cut and paste this into your
> browser:
>
> http://thewallintheartistscafe.com/cgi-bin/artwork/member.pl?artist46&&UserID
>
> There is one other variable that might play into this discussion, and that
> could be the temperature of your bisque you are firing to. It may be possible
> that if you are firing too hot, that the clay body might not be as receptive to
> absorbing the carbon smoke than if you fired a little lower. I'm just tossing
> ideas out to think about here. I'm not certain how much this would be a
> factor, but seems logical to me. I usually bisque to around cone 06.
>
> Thanks for bringing up a good topic for discussion. I'd like to hear others
> thoughts on this... anyone?
>
> Warm holiday wishes everyone!
>
> Ken
>
> "celebrating my 45th birthday this week and feeling better than ever, despite
> having been recently diagnosed with adult-onset diabetes (type II)... in one
> month of being on a low-carb diet... I've lost 10 pounds... dropped my blood
> sugar dramatically from "bad" to "excellent"... and gone from a size 52 jacket
> to size 48!!! Life is good! :-)"
>
> Kenneth J. Nowicki
> Port Washington, NY
> RakuArtist@aol.com
> ...................................................................
>> ellen (e2002meyer@EARTHLINK.NET) wrote:
>
>> A question for the raku guru's........
>>
>> I want to keep the rich blacks on the unglazed areas and have found that
>> wax resist actually penetrates the bisque. The areas where I used the wax
>> do not come out rich black after reduction, they are more of a dark
>> charcoal grey. We are firing to 1850 and getting great blacks except
>> where the wax was and it is noticeable.
>>
>> Is anyone using a paintable resist, that will burn away 100% in the
>> firing, and allow the blacks to be the same as the virgin bisqued area???
>> I am going to try rubber cement....... Any other ideas???
>
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