Donna Kat on sun 26 nov 06
I have been re-reading Mastering Cone 6 glazes and noticed again that most
of the glazes when adding colorants include 6% Rutile. Don't get me wrong,
I really like what rutile does to a glaze, but it is expensive. The book
refers to its lowering leaching and of course adding interest to the glaze.
If I eliminated it from the glaze and used a wash of rutile/nephsye I would
have the movement and interest I want but I would be losing the
stability.... I could of course drop the % of colorants but how much would
I need to do that keep a decent amount of color and the stability of the
original glaze? Then there is opacity and matt. I'm not sure how much the
6% rutile is adding to this. I had planned on moving slowly into developing
new glazes but since deciding to do singlefire work, I find I'm a tad
impatient to move ahead.
John and Judy Hesselberth on sun 26 nov 06
On Nov 26, 2006, at 11:48 AM, Donna Kat wrote:
> Don't get me wrong,
> I really like what rutile does to a glaze, but it is expensive.
Hi Donna,
Hmmm. Last price I had for rutile was $2.00/lb. So in a 20 lb batch--
enough to pretty well fill a 5 gallon bucket 6% would be 1.2 lbs --
$2.40. How many hundreds of pots would that glaze? I suspect you are
talking about less than a penny per pot.
On the other hand, if that penny is really that important, the rutile
does not make a huge improvement in stability. Take it out if you
wish. The difference will not be noticeable unless you are pushing
toward the limits on colorants like copper.
Regards,
John
Steve Slatin on mon 27 nov 06
Donna --
My experience may be totally different from yours, but ...
In general, rutile is worth the cost. It is one of the less expensive
colorants, (RIO and a few others are cheaper) and it provides some
opacity, some 'movement' in appearance, encourages the formation
of crystals, and does various other things.
In some glazes I've tried as low as 2%. I don't get much effect
from 2%. 3% has been good to me, but not in the high-calcium
group, where 4% or higher has given me better effects. At under
$5 per pound (by the time you have a 10 lb batch it should be
comfortably under $5) it's pretty much a deal.
If you want to find out how much is needed, a line blend is a
cheap and easy way to find out where you stand. Line blends
are almost as easy as you'd hope.
Example -- If in your position, I'd start with two 100 g batches
of whatever I'm working with, one at the minimum inclusion amount
(say 2% rutile) and one with a maximum amount (say 10%).
I mix them up with identical amounts of water. The minimum
goes in a plastic cup marked 2%, the maximum in one marked 10%.
I use a syringe to remove (when freshly stirred) 10 ml of each and
squirt it into a cup marked 6%. (the average of 10% and 2%.)
Then I take 5 ml from the minimum mix and also from the 6%
cup, and squirt them into a cup marked 4%. Another 5 ml from
the 6% cup mixed with 5 ml from the 10% cup go into a cup
marked 8% (average of 6 and 10).
If I really want to fetishize the process, I'd start with slightly
more in the first mixed cup and repeat the entire process giving
me all integer percentages, 2 through 10 -- but who needs that?
Then I dip test tiles into the mixes (I number my tiles when I make
them, but if you don't, you can use a RIO wash to note the
percentage in the test on each tile).
You may find something very interesting in your own tests that
the rest of us don't know about.
Best wishes -- Steve Slatin
---------------------------------
I have been re-reading Mastering Cone 6 glazes and noticed again that most
of the glazes when adding colorants include 6% Rutile. Don't get me wrong,
I really like what rutile does to a glaze, but it is expensive. The book
refers to its lowering leaching and of course adding interest to the glaze.
If I eliminated it from the glaze and used a wash of rutile/nephsye I would
have the movement and interest I want but I would be losing the
stability... . I could of course drop the % of colorants but how much would
I need to do that keep a decent amount of color and the stability of the
original glaze? Then there is opacity and matt. I'm not sure how much the
6% rutile is adding to this.
Steve Slatin --
Well, he came home from the war
With a party in his head
And a modified Brougham DeVille
And a pair of legs that opened up
Like butterfly wings
And a mad dog that wouldn’t sit still
---------------------------------
Everyone is raving about the all-new Yahoo! Mail beta.
Nancy on mon 27 nov 06
Hi John
I would love to know where you get rutile. My supplier in Syracuse, NY
charges over $5 per pound and I also love what it does to the glazes and
would use it more if it weren't so expensive. Anyway, if you'd care to
share your supplier, I'd love to save some money on the rutile.
Thanks in advance
Nancy
www.hilltoppottery.com
John and Judy Hesselberth wrote:
> On Nov 26, 2006, at 11:48 AM, Donna Kat wrote:
>
>> Don't get me wrong,
>> I really like what rutile does to a glaze, but it is expensive.
>
> Hi Donna,
>
> Hmmm. Last price I had for rutile was $2.00/lb. So in a 20 lb batch--
> enough to pretty well fill a 5 gallon bucket 6% would be 1.2 lbs --
> $2.40. How many hundreds of pots would that glaze? I suspect you are
> talking about less than a penny per pot.
>
> On the other hand, if that penny is really that important, the rutile
> does not make a huge improvement in stability. Take it out if you
> wish. The difference will not be noticeable unless you are pushing
> toward the limits on colorants like copper.
>
> Regards,
>
> John
>
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>
L. P. Skeen on mon 27 nov 06
Well good grief, you're in New York - everything is more expensive
there, LOL. Have you checked USPigment.com? Their price today on
"rutile" is $2.50/lb and "rutile - light" is $3/lb.
L
Nancy wrote:
> Hi John
>
> I would love to know where you get rutile. My supplier in Syracuse,
> NY charges over $5 per pound
John Hesselberth on mon 27 nov 06
On Nov 27, 2006, at 2:01 AM, Nancy wrote:
> I would love to know where you get rutile. My supplier in
> Syracuse, NY
> charges over $5 per pound and I also love what it does to the
> glazes and
> would use it more if it weren't so expensive. Anyway, if you'd
> care to
> share your supplier, I'd love to save some money on the rutile.
Hi Nancy,
Del Val Potter's Supply has it in their catalog at $1.81/ lb when you
buy 10 lbs. They are on the north side of Philadelphia
(215-233-0655). Judy Wilson, the owner and sometimes Clayart member,
is one of the best suppliers. The Ceramic Shop in Philadelphia lists
it at $2.75. Bailey and Sheffield list it at $2.60 or so. I haven't
bought any recently so these prices may have changed, but they are
from their current catalogs.
Regards,
John
Snail Scott on mon 27 nov 06
At 11:48 AM 11/26/2006 -0500, Donna wrote:
>...I really like what rutile does to a glaze, but it is expensive.
Is the cost of rutile really that much of
a deal-breaker, if you like the effect?
After all, if the work doesn't sell as well
without it, it's a false economy.
Most glazes don't use much of it - I can't
imagine any glaze needing more than a
couple dollars' worth in a five gallon
batch.
Can you go in with a ceramist in your
area to buy in quantity and reduce the
per-unit cost? (A lot of us did that when
cobalt prices spiked, a few years ago.)
-Snail
Donna Kat on tue 28 nov 06
On Sun, 26 Nov 2006 20:50:43 -0500, John and Judy Hesselberth
wrote:
>On Nov 26, 2006, at 11:48 AM, Donna Kat wrote:
>
>> Don't get me wrong,
>> I really like what rutile does to a glaze, but it is expensive.
>
>Hi Donna,
>
>Hmmm. Last price I had for rutile was $2.00/lb. So in a 20 lb batch--
>enough to pretty well fill a 5 gallon bucket 6% would be 1.2 lbs --
>$2.40. How many hundreds of pots would that glaze? I suspect you are
>talking about less than a penny per pot.
>
>On the other hand, if that penny is really that important, the rutile
>does not make a huge improvement in stability. Take it out if you
>wish. The difference will not be noticeable unless you are pushing
>toward the limits on colorants like copper.
>
>Regards,
>
>John
>
My cost for Rutile on checking is over $5/lb but that is far less than I had
remembered it being. I think in grams for glaze measures as well and often
fail to convert properly in my minds calculation so that 600grams seems like
a great expense until I work it out -> 1.3 lbs or ~ $7 per bucket... That
isn't terrible after all but when every one of your glazes uses that much it
seems a lot. Plus I am and always will be at heart a poor peasant....
On looking at my price list I noticed that Titanium Dioxide is only
$2.70/lb.... Couldn't I use that and just throw in a touch of Iron and
Zirconium Dioxide...
That must be a pricing error...
Steve Slatin on wed 29 nov 06
Donna -- I have experimented with this, and often it doesn't work.
I have theories about why. People who know more than me
want to see better tests, and I haven't gotten around to doing
them, so I'll restrain myself and not provide my theory, but
my experience is you'll get some of the same background color
effects but not the same surface or other effects.
-- Steve Slatin
----------------------------------
Donna wrote :
On looking at my price list I noticed that Titanium Dioxide is only
$2.70/lb.... Couldn't I use that and just throw in a touch of Iron and
Zirconium Dioxide...
Steve Slatin --
Well, he came home from the war
With a party in his head
And a modified Brougham DeVille
And a pair of legs that opened up
Like butterfly wings
And a mad dog that wouldn’t sit still
---------------------------------
Check out the all-new Yahoo! Mail beta - Fire up a more powerful email and get things done faster.
John Hesselberth on wed 29 nov 06
On Nov 28, 2006, at 12:32 AM, Donna Kat wrote:
> On looking at my price list I noticed that Titanium Dioxide is only
> $2.70/lb.... Couldn't I use that and just throw in a touch of Iron
> and
> Zirconium Dioxide...
Hi Donna,
Well TiO2 and a touch of iron oxide might do it--I'm not sure what
zirconium dioxide has to do with it--, but you might also consider
changing suppliers. As you have seen the last few days others are
able to buy rutile for $2.50 give or take a bit. If you do try to
make "synthetic rutile" be sure to test, test, test. It can be tricky.
Regards,
John
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