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Post by hughey on Jun 29, 2017 14:43:42 GMT -6
I just loaded the new kiln with the first batch of crystalline glazed pieces. Just four to start with. Everything is new to me, so I have a couple of questions. Here is the background on the clay bodies and glaze.
four pieces in B-Mix 5
two pieces glazed with
Ferro frit 3124 51.4
Zinc Oxide 22.5
Silica 21.0
Lithium Carbonate. 5.1
1/2 % Co
1% Cu
two pieces glazed with same base glaze with 3% Ni
Firing schedule:
1. 300 1000F. 0:00
2. 500 2183F. 0:15
3. 9999 1832F. 0:30
4. 500 1976F. 3:00
my first question is glaze consistency. I sifted everything through a 100 mesh screen and used tap water to mix. The first coat of glaze went on easily, acting very much like Coyote glazes. The second and third coats produced bubbles as soon as the brush touch the clay body, and on the two pieces with the Nicole colorant, caused some cracking of the glaze. I smoothed everything out by rubbing lightly with my finger after it dried, so I am hoping it will not separate during firing. Since I am unfamiliar with these glazes, is that fairly common or did I do something wrong/ leave something out? I guess I'll find out Saturday, but if anyone sees a glaring error let me know.
thanks,
paul
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Post by hughey on Jun 30, 2017 11:45:19 GMT -6
I took a quick glance in the kiln this morning and things looked pretty good. Good glaze runoff into the catchers, good color, good coverage from what I could see. I didn't see any crystalline growth, but there might be some there. I will post some pics once I get home and can get the pieces out of the kiln. I think one of the problems I was having with the glaze bubbling on the bisque ware might be fixed by adding a little CMC to my glaze. I'll try that with the next run.
Paul
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Post by hughey on Jun 30, 2017 16:22:05 GMT -6
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Post by hughey on Jun 30, 2017 16:24:33 GMT -6
So, no crystal growth on the vases, but some in the catchers. I am assuming I didn't get the glaze on thick enough. I will try again with the CMC added to the glaze and see if I get better results. I do like the colors I achieved, especially the cobalt/copper mixture. Any feedback is very welcome.
Paul
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paul
Junior Member
Posts: 51
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Post by paul on Jun 30, 2017 19:37:18 GMT -6
If you are going to fire cone 5 get the Jon Price book and look at the low fire recipes. Use Ferro Frit 3110 for the best and easiest crystal growth. I believe without double checking the FF 3124 has "Boron" in it which is perported to kill crystals. I have never seen any verifiably good recipes using 3124. Use Denzox brand zinc oxide, at least make sure you buy that or Horsehead is in my opinion second best. Porcelain works better than either B-mix 5 or B-mix 10 as far as glazing, but is harder to throw, you can wedge them together 50/50 for better overall results. Make different glaze test recipes with 50 to 250 test tiles and fire them to find acceptable glaze results with different recipes before you waste your vases without having any idea what you are going to get. You can buy a big box of small plastic jars from a place like Uline, you can google their web site ..........make a load of small batches like 50 grams each, Get a plan  Hope that helps for a start |
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Post by hughey on Jun 30, 2017 20:49:56 GMT -6
Thanks for the input Paul. I am throwing with both B-mix and porcelain. I actually like the porcelain better, but the B-mix is more cost effective for some things. I don't mind using these pieces for tests. They are learning pieces, so it's all good. I am going to fire a load using 3110 tonight. The recipe I used with 3124 is from the Jon Price book. It was one of two recipes they showed pics of finished pieces that had good crystal growth so I thought I would give it a try. The 3124 piece (page 110) was covered in crystal growth, so it is possible to get good results with that frit. I think my big mistake with that trial was using plain water and not getting enough glaze on the pot. I mixed up a small batch of 3110 glaze this afternoon using water with CMC added and the glaze flowed on much better and I was able to get a thicker layer down with each coat. I'll try the 3124 recipe again soon and let you know if I get anywhere with it. I do plan on doing a series of test tiles in a few days. Between all of the books I have read, there are a lot of glaze recipes I want to try. I also have some pieces in B-Mix and Laguna cone 10 porcelain pieces that are ready to be bisque fired, so some cone 10 glaze test are in the near future. I'm just beginning this journey, so I don't expect amazing yet... but I will get there.
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Post by hughey on Jul 2, 2017 8:06:48 GMT -6
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Post by hughey on Jul 2, 2017 8:18:22 GMT -6
Second time around was much more successful. The two blue pieces are #9 low fire glaze from Jon Price's book with copper and cobalt added and firing to cone 7. The green pieces were a gamble and I didn't get any crystalline growth, but the color is pretty cool. #7 low fire glaze but substituting whiting for the strontium carbonate and coloring with 4 parts green nickel Oxide. I'm trying the #8 glaze recipe next while I get some cone 10 pieces bisqued. Once those are ready to glaze I have a few cone 10 recipes I want to try out. I wish I had more time to be more methodical, but I'm trying to get some pieces finished for a show soon. They will either work or they won't... I'm just having fun playing with the new kiln and getting to know it.
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fa
New Member
Posts: 21
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Post by fa on Jul 2, 2017 8:20:08 GMT -6
The best crystals are always in the catchers. As for boron killing crystals, heck, no! My most reliable glazes have plenty of it in them. 3110 is a boron frit, and a little gerstley borate in a glaze can work wonders.
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Post by hughey on Jul 2, 2017 12:08:12 GMT -6
Thanks for the advice Fara. I am trying out a glaze today that has Gerstly in it. When I get to my cone 10 bodies a I am going to try out your Bory 1 glaze. I've been using your books for reference and they have been such a help. Thanks again!
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Post by jfox on Jul 2, 2017 12:33:28 GMT -6
I add about2% gerstly mosty for the improved suspension and brushing most of those tests look either overfired or try added zinc or reduce flux
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Post by hughey on Jul 2, 2017 14:52:30 GMT -6
Thanks for the input, Jim. I'm going to tweak a couple of things on the next firing to see what I get. The last firing schedule was 2246F with 15 minute hold, down to 1832 F for 30 minutes, and back up to 1976F with three hour hold. This is a cone 7 glaze. I was thinking to bring the top temp down to 2210F with no hold and leaving everything else the same. Also, the recipe that I used on the cobalt/copper pots that had some crystal growth did not call for titanium dioxide, so I thought to add 3% to the mix to promote more crystalline growth and up the % of zinc. Does it sound like I am on the right track?
Paul
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Post by jfox on Jul 3, 2017 8:22:45 GMT -6
looking at that frit, there are alot of issues
Ferro Frit 3124
Leadless high calcium borosilicate frit
Alternate Names: F3124
Oxide Analysis Formula
CaO 14.28% 0.697
K2O 0.68% 0.020
Na2O 6.40% 0.283
Al2O3 10.01% 0.269
B2O3 13.74% 0.541
SiO2 54.94% 2.505
Oxide Weight 274.12
Formula Weight 274.12
high calcium high boron high alumina, not saying it wont work but youd have easier time with 3110
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Post by jfox on Jul 3, 2017 8:26:51 GMT -6
I seem to go around in a cycle that last a few years of slowly jacking up the temperature trying to get a more consistent and kiln wide result till im tourching everything past cone eleven then I add more lithium and try to drop back to about 7-8 and while i get some promising results i start slowly upping it . overall id say the best tradeoff is the 9-10 zone
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Post by hughey on Jul 4, 2017 9:10:03 GMT -6
Im thinking I will find a liner glaze recipe to use up the 3124 frit. I have gotten some good results with the 3110 with the cone 6 recipes I've tried. I just loaded a bunch of new pieces using mostly Fara's Bory I recipe and am firing to cone 9. We will see how those turn out. I've used up,all of my cone 6 clay pieces for tests, so now it's to the big guns...
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Hope that helps for a start
