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Pam S

Amaco Ancient Jasper Question

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Teardrop- Thanks for the inspiring photos of your use of this glaze (not to mention your wonderful pots!). I think I may need to revisit this glaze!

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Yer welcome Pam!

 

It's an awesome glaze IMO. I think the problem most folks have is that they are far too shy in their application. This one likes to be applied very thickly. When you think you've put enough on...put more on. :lol:

 

fun stuff

 

teardrop

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I've been using this glaze over a year now and it didn't start out well. Here's what I found: First the clay makes a big difference. I settled on b-mix or cone 5 porcelain as I get consistently nice finishes. I also dip my pieces so I just hold them in for a 4 count. Fast fire to cone 5 as the engineer suggested in a previous post. the important thing is not to skimp on the glaze. It doesn't seem to matter where I place them in the kiln. I am a new potter so I am not speaking as an authority just experience. Good luck.

 

 

Thanks for mentioning that you dip for 4 - I am considering using AJ for a larger run of pots (wine goblets for me wedding actually!) and have so many to make that brushing would be a real time suck.

 

Any chance you could share your firing schedule also?

Thanks!

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Wow! Ancient Jasper glaze has really started some interesting comments. And to think I started it!!. I salute Steve @ Amaco for the info stuffed response about this glaze and I learned tons from the other members of this happy clay club about firing etc. I love the look of this glaze and will continue to test it based on advise from all above. However, I'm still concerned about firing so hot so quickly. Am I not endangering the remaining ware in the kiln with such a speedy method?

Asunta

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I've been using this glaze over a year now and it didn't start out well. Here's what I found: First the clay makes a big difference. I settled on b-mix or cone 5 porcelain as I get consistently nice finishes. I also dip my pieces so I just hold them in for a 4 count. Fast fire to cone 5 as the engineer suggested in a previous post. the important thing is not to skimp on the glaze. It doesn't seem to matter where I place them in the kiln. I am a new potter so I am not speaking as an authority just experience. Good luck.

 

 

Thanks for mentioning that you dip for 4 - I am considering using AJ for a larger run of pots (wine goblets for me wedding actually!) and have so many to make that brushing would be a real time suck.

 

Any chance you could share your firing schedule also? I just fire like Steve @ Amaco said :cone 5, fast, hold for 5 min then let cool. I keep my top plug out until the kiln has stopped firing then put the top plug back in.

 

Thanks!

 

 

 

 

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More bad/newbie-made pottery glazed in Ancient Jasper

 

 

brushed on heavily (5 coats) at the top...lessening to 2 coats near the bottom....

 

 

hangtag in place...(thanks for the idea) and ready to be sold to people who evidently have even less of a clue what "good" pottery is :lol: than even I do...

 

 

yes...I'm funnin' with ya...sorta...

 

beautiful. how much do you sell them for?

 

 

 

 

 

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We pulled this out of the kiln last night and were completely blown away.

 

2 (dipped) coats of PC Firebrick Red (from dry mix) on the bottom.

 

3 heavy/drippy coats of PC Ancient Jasper (straight from a well shaken bottle) applied with a bulb syringe on top. The stuff was globbed on liberally and the runs on the side were fat and thick.

 

The only surprise was that the saturation GOLD I placed on the top edges came out a silver/metallic. Though I LOVE what it did...that wasn't what I thought it was gonna do.

 

I will definetely be working more with this combo in the future!

 

teardrop

 

 

 

what kind of clay are you using?

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Has anyone tried this glaze? I just took Ancient Jasper out of the kiln. It is a beautiful dark eggplant color, but not what it was supposed to be. I fired the the load to ^6 with a slow cool (medium down to low then off to finish) it was a load of only reds and red/blacks. Refiring perhaps or not firing it with reds? I think I need to change my user name to the Frustrated Firer!

 

 

I have had great success heavily applied on a buff glaze, with a 30 min. hold and firing to cone 5. Cone 6 always has been too high to get any true colors from the Potters Choice glazes. In addition to Ancient Jasper I've fired Rutile Blue, Chun Plum, and the Chun Plum over Rutile Blue. Again, all succeses were glazed heavily.

 

Newmarket Potter

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Guys,

 

 

These are photos of a pot made by Danny Meisinger of Spinning Earth Pottery. It shows how the red naturally breaks to other colors around texture.

 

Steve............attachicon.gifIMG_0412web.jpgattachicon.gifIMG_0276web.jpg

 

ANCIENT JASPER: Hello all and stay with me as I am and old guy and not blog capable. I am the VP of Technical Services here at AMACO and the engineer that developed this glaze. I am very sad to hear that some of you are having difficulty with this glaze. It is actually a very easy glaze to work with and will yield excellant results. Let me give you a few tips on this type of glaze in general an then some specifics about ANCIENT JASPER.

Many midrange and high fire glazes used by ceramic artists are what I call FLOAT glazes. These are the pretty glazes that tend to seperate out different colors in areas where the glazes are thicker. ANCIENT JASPER is this type of glaze and what it floating out is iron oxide. Iron is one of the more interesting colorants simply because it can be in so many different oxidation states. This simply means that it can make a ton of different colors. With any float glaze, enough thickness of glaze must be applied in order for the excess iron to float to the surface. If the glaze is thinly applied, the glaze will tend to be drier and a very unpleasant color.

This glaze was not developed where any massive amount of glaze needs to be applied. If it had needed this I would have told everyone on the label. We actually never had any issues getting red at all. I always try new glazes on all of our clay bodies to make sure there isn't some issue I need to know of. We also fire them at cone 5 and cone 6 to check stability. We found no issues with this glaze on either account. By now you probably saying, great but it didn't work for me. I will list some good parameters below for you to follow and I am 100% sure you will find this glaze simple to use and that it will yield great results.

1. Temperature: The red color is actually the first color to float and the use of more heat will tend to make it turn to the purples, yellows, browns and black. This means you will tend to see slightly (and I do mean slightly) more red at cone 5 than cone 6. No soak is needed for this glaze and actually soaking it will cause more red to fade into the other colors.

2. Thickness: The glaze must be applied with enough thickness to float the iron.

3. Kiln cycle: I fire all the glazes we develop in an electric kiln at fast, medium and slow speeds. Red color will be developed at all speeds but the faster the firing ~6 hours (tons of red) the better the results. I always quality check each batch at cone 5 in 8 hours. 10-12 hour cycles will cause more red to fade to the other colors. This is most critical within 200 defrees of peak. If your elements are weak and it takes the kiln a long time to achieve the last 200 degrees, you will find less red.

4. Cool down: No special cool down is needed nor will it help develop any red color. Letting the kiln simply shut off and cool naturally is all that is needed.

4. Clay Body: I have tested this on porcelain, typical stoneware bodies, bodies with grog, bodies without grog, brown colored bodies, etc. I develop red on all of them. I have found that when using our #1 Porcelain slip that the color transition away from the red tones is very pronounced (although it makes a rainbow of the other colors). This is because for a cone 5 porcelain slip alot of soft flux is needed to tighten the body. The flux in the body mixes with the glaze and actually makes the glaze softer (simulating more heat).

5. Texture: This glaze loves texture and will make some incredible colors. The texture makes the glaze get thinner and thicker in areas. The thicker the glaze the easier it is for it to stay red. The thinner the glaze gets the hotter that area of glaze gets and it shifts to the other colors.

 

These simple tips should help everybody that wants to make ANCIENT JASPER work. I suggest running a few tests of glaze thickness in your next kiln load and follow the firing rules above. Three nice coats on any typical stoneware body, fired to cone 5 or 6 in 6-8 hours with no soak and no special cooling curve will yield pieces just like the ones we showed in the ads. These were just pots we made in the lab. Honestly I have never actually made a pot that didn't make colors just like those pieces.

I will attempt to post a few more photos here today and next week we will post a board I made with all of our clay bodies fired at slow, medium and fast so you can see the slight differences.

Let me know if this helps.

The photo files are too big to upload. I will have someone help me make them smaller for next week.

Steve.........

I am working with blue midnight 3 base coats then Blue Rutile one coat 2/3 of the way up then second coat 1/3 then third coat on rim.  I want a darker on the blue midnight . I am close to the first dishes I made with only 2 medium heavy coats of blue midnight and same three layered blue rutile . I bisque to 03 . i use MB White stoneware cone 6-10 wet. It is a stoneware porcelain mix.  I then fire to cone 5 electric paragon sentry 2.0.   rate 1 324 temp 1 1022, rate 2 153  temp 1112, rate 3 162 temp 3 1951, rate 4 108 2167. hold 20 minutes.  I have pinholes what am I doing wrong??? How can I fix the pinhole problem??

 

 

 

Sorry the pictures have to be so small to upload.

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