Zinc Silicate Crystalline Glaze Pottery
Richard the 3rd:
Here's one from a small load on Thursday (some mugs, which didn't work as planned, and some more vases...). This one is 9" tall with most crystals 2 -3" across. It was more of the now-infamous Richard the 3rd, fired to cone 6/7 (2200F max, but my kiln crawls at that temp so cone 7 was soft).
Steve Klinski (Uneven Firing) Large plates and bowls fired in my large gas kiln have been turning out pretty nice on the inside, but spectacular on the outside. Is it because ....."
The outside of your bowls have enough draft to allow the glaze to shear enough
to behave like a vertical surface. The inside doesn't and is behaving like the
horizontal surface that it is. You might like to try slightly different
versions of the same glaze for the interior and exterior. Adding 3% flux to
the interior glaze may be a good starting point. Good luck!
On all our flatware we increase the glaze amout by 50%, fire to a cone hotter (^11), and the last ramp goes up at 115F per hour to top temperature. Hope this helps.
Best, Kris (Friedrich)
(Adds up to 92.9)
1 Nickel Oxide
5-18-05 John Mankameyer http://www.crystallineglaze.com/index.html
73 year old? Been doing this since 1973 - used to be electronics Engineer. Lives with 102 year old mother in Montana. Formerly lived in California. Every firing is an experiment. Herbert Sanders PhD, Syracuse Ebberson Museum told him 20 years ago he has mastered crystalline glazes and it's time to move on.
Uses Pemco 283 frit. Unavailable for 10 years now. Has 500 lb. from original 3000 lb stash. Claims 3110 is too shiny for his taste. Uses Mile High Ceramics "Zen" porcelain. Fires between 1500 and 2000F. ^10 flat, ^11 1/2 way down then drops to 2000F. Agate look is formed by ramping down to ~1600F then coming up again staying on low end. First he said 1500F, then corrected it to 1600 and added if you go to low you may stop the crystal growth and can't get it started again. Multiple times? He fires at low end of crystal growth range to get rounded crystals. Higher temps yield larger, but spikier crystals. He's made some 5" in diameter. Used to go for size (when he was younger). Now goes for Agate look. He uses a 2.3 cu ft Cress kiln with 2 1/2" brick. Fast kiln. Has rebuilt many times. Winds his own elements. Canadian wire? Gets ~40 firings per element. Fires everything by hand. No programmer. Reduces in this kiln. Adds oily rags.
|5-18-07 Jay Dubiel (collector) 434-575-5781 called saying he has one of everybody's except mine. Wants Chris Groat purple vase. Couldn't believe it's not for sale. Kept asking "why do you do it if it's not for sale?"|
Tel from states (UK international code) 594 823241
I packaged 3 1/3 kg Ferro 3110 in 3 each 1 gallon plastic buckets (for a total of 10 kg) and sent it via the United States Postal Service's "Global Express Mail" this morning. They guarantee delivery in 3 to 5 business days. Hopefully you'll get it by the end of the week. This service cost me $107.25. For ~$5 less I could have gotten their 5 to 10 business day service, but figured you could use the material right away. The USPS Label Number is EB201949993USThe Customs Declaration Form is # CP970396662US. I will hold onto the paperwork here. Please let me know when it arrives. I labeled it as a gift (a birthday present). How old are you.....28???
I looked at UPS first and the price was insane! It would have cost ~$200+. I am sure DHL would have been about the same.
This turned out to be more time consuming than I had expected, but if it helps you out of a bind that's great and hopefully you can be my "Knight in Shining Armor" someday.
As far as "any preference for shape/size/colour" is concerned I have 5 requirements of the piece(s) you send. They include:
1) It is (they are) beautiful
2) It is (they are) beautiful
3) It is (they are) beautiful
4) It is (they are) beautiful
5) You made it (them) so I will always have something I look at and say "Man, isn't it (aren't they) beautiful! It (they) was (were) made by my good friend Avril Farley.
No problem. I can send it Monday. Is your ship to address on your web page? Can you copy me regarding your answer at work too? My e-mail is firstname.lastname@example.org I'm sure I can send it FedEx or DHL. I will call it a gift, but probably will have to declare some nominal value. If you want to pay me, how do you feel about sending some of your work, as a gift of course? Phil
From: Avril Farley [mailto:email@example.com]
Sent: Sunday, April 08, 2007 5:06 PM
To: Phil Hamling
Phil, that is so kind of you. I would be very very obliged if you could send me 10 kilos. of FF3110. How can I pay you? International money order? Credit Card? let me know please. If you do send it can you call it a gift,
please. Best wishes Avril
Phil, the recipe for this glaze is 3% light rutile and 1% cu carb. The iron
came from the rutile, although Limoge special porcelain is also in itself
quite high in iron. This would have been fired ( as I remember, my recipe
book not being to hand) in a 1250 firing, coming through a crystal
forming period of about 5 stages the last of which would have been a slight
raise, probably from 1045c up to 1055 for 10-15mins. Unfortunately since I
ran out of that particular batch of rutile , I have come near to , but not
able to reliplicate the exact results for this particular combo.
For encouragement, this is an example of a three times fired 15" flat dish -
one of my best early pieces which started out scaled - there is a
particularly nice huge crystal in the base. I often refire, it is
surprising how things can get better. I like Jesse's idea of the hole and
'jewel' base. I've not tried this but may now.
I am not sure what you mean about 'blank spots' but this is the result of 3%
strontium (which I use as a substitute for Barium) and 2% cobalt in my
FF3110 base glaze.
Avril in the forest UK
875 N.W. 65th Ave.
Plantation, FL 33317
attn. TERRY FALLON
3071 N.W 64th AVE
SUNRISE, FL 33313
ramp up as
you like to 1990°f and add hold at this point for 10 minutes or longer to
reduce number of crystals, the glaze should be completely melted at the
start of this hold if not increase up to get full melt
9999 dn to 1840°f hold 15 minutes this should take 30 to 40 minutes.
50 up to 1980°f hold 10 minutes (nice round crystals if glaze is not to thick, more flowery and transparent where thick. More flowery if over 2020°f
to1840°f hold 50 minutes this gives a halo
|new mix 02-21-2007.xls||Use "Rainex" to improve shine and "POP" of finished pieces.|
on an orange ground is primarily nickel by it self, try 2% Nickel Oxide or
to get more orange in the ground add manganese dioxide, more yellow ground add black iron, green in the ground add cobalt.
MOST IMPORTANT KEEP TITANIUM at less than 2% and maybe less than 1%
Titanium makes nickel turn either brown or green you will not get blue crystals with the 8% tio2 in your base glaze!
for your eyes only
lids for that all over effect.
A little lithium with iron will make the iron "Pop" and bring out the gold color.
I do have some new greens.
Some low holds. first halo1800°f , second halo 1750°f last black halo 1690°f
ps. Fallon§Classic clay
Mr. ( )
Latest one out the kiln.
|William Melstrom||Forum Password: Sc00ter|
The colorants for the purplish glaze are 0.42% Co (carbonate), 1.0% rutile and 1.33% Mn (dioxide). This is a super secret recipe, and although I know that everyone is going to get different results, I don't want you to share it.
The key is the Mn, which can do very weird things, such as blush reddish, in the right conditions.
That glaze is the basis of my super secret "ruby." Where POOLED, it usually turns ruby or orange when STRUCK
These are before and after pictures. Note that where the glaze pools in the first pic it becomes an unappealing transparent grayish-blackish purple-blue.
Phil, Here's my base:
zinc ox 19.1
Ball clay 1
titan. diox 4.76
does not add up to 100.
From: William Melstrom [mailto:firstname.lastname@example.org]
Sent: Sunday, March 04, 2007 10:58 PM
To: Phil Hamling
Subject: Re: Post 1098
My final segment is a long hold at 1000C. My cooling consists of rate 85 to 940C, then rate of 60 to 800C, then I crack the kiln. That's comparable to your 2 hour cool down ramp. The difference in color remains inexplicable to me.
When I'm striking, I usually have plates, so my strike rate is extremely slow to avoid fracturing. Rate of 65 to 690C, then a fire-down of rate 65 to 300C, then off.
I was trying to remember what you told me regarding changes to make when firing horizontal ware and am drawing a blank. Did you say to lower the growth hold by ~40C? I thought there was a 2nd point but feel like an Alzheimer's victim.
to avoid the spikiness, and get back to nice, round crystals, lower "all" (if, for example you have a schedule with growth rings) of your lower temps by 35 degrees. Raising the peak can also sometimes reduce spikiness. Lower your overall growth time so some background remains. Lots of people have tremendous problems with pooled surfaces. It might take a lot of work.
William uses Coleman porcelain
Fast firing up and down in ~8 to 9 hours. Important to have 1/2 hour hold at 800C to prevent bloating.
|Dwight||Dwight's comments on Chris Groat's work|
I just chose a very simple schedule as we were pressed for time and I wanted
to be able to show some principles.
I think the schedule was:
150 to 150 hold 20min
265 to 2350 hold 0
9999 to 2000 hold 2 hours
9999 to 1850 hold 1 hour
Cool. As in cool the kiln.
In this way you can see that:
1>There were 2 main places where the crystals were growing.
2>But there are more than 2 places where the crystals were growing so they had to be also forming as the kiln was heating and cooling. That is, the crystals are also forming as the kiln is trying to get to the temperatures we have programmed. We had a lot of pots in the kiln (I like to fire with just a few pots) so we were not going to be able to get to a different temperature quickly.
3> Crystals are different colors at different temperatures. The soak at 1850 was to put a ring around the basic crystal. I think this is really important as it allows someone who is energetic enough to know what colors any particular glaze can give.
John on crazing
Anne Gary wrote ;
I am baffled. Some of my vases have crazing and others do not. Same base glaze fired on the same program to 2230 (cone 8 at 9 o clock when done). They are applied to the same slip cast body.
The glaze recipe I use is Fara's BORY 1 Recipe
> Ferro Frit 3110 50
> Zinc Oxide 27
> Silica 16
> Titanium Diox 4
> Gerstley Borate 3
> The slip cast body is:
> Kona F4 20
> Minspar 16 (supplier ran out of Kona and substituted Minspar, does this matter?)
> Grolleg 31
> Flint 200 17
> EPK 15
> Bentonite 1
> This crazed sample has 1% tin, 3% Ilmenite, 0.5% cop carb
> Next crazed sample: 1.5 cop carb, 1.5 cob carb
> Crazed sample: 1.5 nick carb, 1.5 cerium
> Uncrazed sample: 4% rutile, 1% Ilmenite, 3% Cop Carb
> Final uncrazed sample: 4% titanium
> Should I tweak the base for the crazed glazes. What would you do to it to stop the craziness!
> Last question, is there any way to not have crazing on the bottom of a platter. If there are not crystals covering it, I always see crazing.
> Thanks much for the help
> On my 25th firing and looking forward to John's workshop in February!
Post Firing Reduction Dialogue
I plan on setting some of my fired crystalline pots aside
for some post firing reduction - firing in a small gas fired updraft kiln to a
I've read various information in the past about reduction firing in an electric kiln during the cooling phase, but I'm not keen on introducing combustibles into my electric kilns.
I was thinking the 1600° - 1800°F range with fairly heavy reduction (flames & smoke like back in the old days of firing kilns) but suggestions for a target firing temperature are invited.
I will need to get the glaze to the start of melt to allow the carbon monoxide to react with the oxygen contained by the copper, but not so hot that I reach a temperature that would affect the crystals.
Any suggestions for percentage of copper in the glaze?
According to Peter Illsley take the kiln up to 800c then slow HEAVY reduction to 600c then pray.
For post-fire reduction:
I have had my best luck in the .5% to 2% range of Copper Carb. Varying the
reduction time from 45 minutes to 10 minutes can yield some nice variety also.
Try it with a high Titanium glaze with no colorants and see what happens.
As Avi mentioned, Peter Ilsley suggests firing down from 800 C to 600 C (1472 F to 1112 F). I think it is important to make sure you finish at a low enough temp. that it cannot reoxidize at the end.
try also adding a small amount of copper to a cobalt blue glaze, and if all is well with the kiln gods, the copper may go to the crystals for red on blue. Good luck.
8399 Roelke Rd.
Blue Mounds, WI 53517
You already have the basics... beyond that there is no simple "how to".
The obvious first hurdle will be in finding the peak temp. for your glazes.
You should reduce at the highest temp possible. The higher your glazes will let you go, the deeper the reduction effect will be achieved INTO as well as on the glaze surface.
*Here's a short cut*:
The quickest and easiest way to find the peak temp. to take your post-fire reduction kiln up to is to ...not fire it.
Although the reduction atmosphere will have a marginal effect on the glaze softening, you can find your temp. maximum more simply by using your computer controlled electric kiln. By programming successive firings, you can find this w/o having to manually fire the gas kiln. Once you've established the highest temp you can take your glaze to before it's aesthetic is ruined, you can reduce at the highest temperature beneath that. That top temp is going to be defined as much by your own opinion as anything else. I personally like the "dryer" matte surfaces I've been getting with post-fire reduction as much as the color effects:
It took me 3 firings to find my own temperature window for just one base
glaze, and that will vary with additions of titanium, colorants, etc.
We've already had conversation threads concerning outside temp's, wind gusts, and barometric pressure... all those extra variables sometimes just make you look at the firing results, then your own notes, and just laugh. No matter how much you learn, the kiln gods will always have the controlling shares.
Even after all this, experiment within the entire temp range and with varying amounts of reduction. Believe it or not, the following pictures are the same glaze recipe:
If your kiln is outdoors or in an unheated enclosure, take advantage of the cooler part of the year. The quicker you can drop out of that temp./ reduction window, the less chance you have of the glaze re-oxidizing...
i am planning on learning crystalline glazing (i must be mad
) Welcome to the tea party then...
The most common frits I've used or currently use in the ^8-12 range are:
Ferro 3110, 5301, 3304/3403, 3485
Fusion 75, 413, 466, FZ-24
Pemco P-IV05, P-1084
Mondre and Manz 4067, 1233
Some of the frits listed above can be direct substitutions for each other (3110=75=P-IV05, GF-106=413, 90208m=466, 5301=FZ-24=P-1084) and some are no longer manufactured, although there are quantities still around. Not knowing what's available to you, I listed them all.
I've also used Ferro 3124, 3134 or Hommel 14, 90 as additions to the frits above to get certain results, but because of their boron content they may not produce the best when used alone.
Frits are easier to work with, but aren't your only solution. As far as raw material fluxes, I've used Sodium Carbonate, Kona F4 Feldspar, Potash Feldspar, Sodium Silicate, and Nepheline Syenite along with additions of Lithium, Strontium, Barium, and Calcium Carbonates.
Use Peter and Fa's books to guide you in the initial use of these materials, and then expand on your own as soon as your comfortable with what each does.
Try these as line blends:
1st) Small amounts of manganese and cobalt (less than 1% of each).
2nd) A blend of Erbium and Neodymium offers shades of translucent purple... -I avoid titanium with lanthanides for "cleaner-looking" results...
3rd) Kris gets some of the nicest deep purples I've seen in his Geil with blends of iron/manganese-bearing titania (rutile and Ilmenite) in reduction. Plain titanium (at 6-8% total) gives a nice soft purple.
I've been getting these various forms of titanium to go purple using post-fire reduction as well. Silver with rutile often yields a pinkish purple.
These are starting points, have fun!
17340 Bridgewater Circle
Minnetonka, Mn 55345
I worked on jars for a time and found the variables of size of the lid for the jar drove me nuts. Then there is the knob or handle. They crack along the brim of the top where you push the bowl out to size the lid. So I stopped making them. I'll put a photo. Kirk
Info from Kirk
-You need manganese activated willemite for it to fluoresce.
-Short wave UV Light....UV Systems.....Don
~$400 - Super Bright
~$900 Triple Bright
-Florescent article...John Singer...Clay Times 2005
"Fluorescent Glazes" (Jon Singer), 2005 May/Jun:48-52
-Book....Crystalline Glazes....Donald Holloway.....Louisiana
THE ART AND CRAFT OF CRYSTALS, Donald R. Holloway.
The green is 5% black copper, 1 tit,2bent, snair #2base The blue on gray is 1/4 co, 2 Mn, 1 tit, 2 bent, same base.
written about molybdenum as a glaze material. Our limited research has turned up
a bit of information. It was discovered in the latter part of the 18th century
by a Swedish scientist, Carl Wilhelm Scheele. We are unsure who brought the
technical use of molybdenum in glazes to the U.S. from Europe. We do start
seeing its use during the Arts and Crafts pottery period made during the turn of
the twentieth century. The potters of whom we are aware who experimented with
molybdenum crystalline glazes are Adelaide Robineau, Charles Fergus Binns,
Frederick H. Rhead, Otto and Gertrude Natzler, and Herbert Sanders.
An excerpt by Phyllis Ihrman, from Peggy Weiss’ book about Adelaide Alsop Robineau gives a good description, “The molybdenum crystal is very elusive, less predictable, and more difficult to achieve than most other types of crystal. It differs from the zinc silicate and titanium crystal in that it is usually quite small and shaped like a rectangle, star, or diamond. In multitude they are double refracting, separating light into different colored rays. They seem to float on the surface of the glaze and display all the iridescent colors of the rainbow as light plays over them. The matrix is usually very lustrous and opaque. Often the crystals are very subtle only being seen when the pot is tipped to catch the light.”(1)
(1) Weiss, Peg, Adelaide Alsop Robineau Glory in Porcelain, Syracuse University Press, New York, 1981, page 150
> I would like to expound upon what Terry and Fara have said, and what might be confusing about it.
> Terry is talking about adding moly to a typical recipe. Supposedly, doing this yields a pale yellow, but for me, it is so weak that it can be seen, except for sometimes in the halos. But moly added this way has a significant effect on the shape of the crystals. It makes them more complicated and/or frillier. You might like it, or not, it a personal taste thing. In conjunction with other colorants, it makes them whiter, meaning pastel-like.
> The moly crystals that Fa is talking about, which are explained in the Sanders book, are a completely different animal from zinc-silicate macro-crystalline glazes.
> Here a link:
> Fa mentions growing moly crystals in a tight kiln. I have been told that the moly becomes a vapor, and the crystals don actually form until the kiln is shut off and cooling, and the moly re-attaches to the glaze. My thought has been that the best way to make moly crystals would be in a sagger.
> William Melstrom
Thank you for the help on this. I am still unsure what percentage to use in a zinc-silicate glaze. If I want more color should I try 4%. Terry indicated max 5%. What would you suggest as a first try. I have 4% Titanium in the glaze (if this matters).
Sounds like it does not work well with colorants. So I think I will try it alone.
less than 2% not much change
2% no colorant, nice white crystals
strange results when I used iron
nice with 1.5% nickel
I use very low Tio2 in my glazes.
I've had great success with Moly, using the glazes in Sanders' book. 4% of the oxide or 5% of the sulfate is usually enough, but keep your kiln tightly closed when you fire. The only colorants I've tried are iron and cobalt; cobalt is okay, iron combines with the moly and while what you get is very interesting, it's not what I'd call pretty.