jrgpots Posted March 16, 2013 Report Share Posted March 16, 2013 I live at the base of a cider cone and have collected scoria dust. This is the dust from lava cinders. It is basically ground basalt. I want to add it to Laguna's 50/50 cone 10 clay body. I don't know how much it will decrease the maturation temp of the clay body. Since scoria has a large amount of iron (12 - 17 %), I'm hoping it will give me a nice speckled pattern or even darken the entire clay body. Does anyone have any experience with this type of homemade basalt clay mix? Link to comment Share on other sites More sharing options...
bigDave Posted March 17, 2013 Report Share Posted March 17, 2013 I have lots of fine scoria also, Im wondering the exact same thing All I can find is it melts at 1200-2400 F, arrg, test some and so will I and we can compare notes Link to comment Share on other sites More sharing options...
jrgpots Posted March 27, 2013 Author Report Share Posted March 27, 2013 I live at the base of a cider cone and have collected scoria dust. This is the dust from lava cinders. It is basically ground basalt. I want to add it to Laguna's 50/50 cone 10 clay body. I don't know how much it will decrease the maturation temp of the clay body. Since scoria has a large amount of iron (12 - 17 %), I'm hoping it will give me a nice speckled pattern or even darken the entire clay body. Does anyone have any experience with this type of homemade basalt clay mix? Well, I added scoria dust to Laguna 50/50 clay body, threw a small bowl, and fired to bisque (cone04). The scoria did not melt or leave any iron spots. I understand cone 5 is around where basalt should melt (1200 degree C) .....I hope. I will leave part of the bowl unglazed, one third glazed with an opaque cream, and one third with clear glaze. If it works, I'll post a pic. Link to comment Share on other sites More sharing options...
bigDave Posted March 28, 2013 Report Share Posted March 28, 2013 cool, I have one in process drying, you are week ahead or so, very interested and hopeful for some cool blacks specks or spots or sumptin' thanks for the update -big D ps. how fine is your dust. I am using the fines that come thru a window screen. This is a part of my soil/substrate for bonsai growing. I use lots of scoria but have tossed the fines in the garden for 20 years, then go and by grog and iron ox etc by the bag. Been wondering for a long time if could substitute this material for iron or manganese, or grog ? So we will find out soon right Link to comment Share on other sites More sharing options...
jrgpots Posted March 28, 2013 Author Report Share Posted March 28, 2013 cool, I have one in process drying, you are week ahead or so, very interested and hopeful for some cool blacks specks or spots or sumptin' thanks for the update -big D ps. how fine is your dust. I am using the fines that come thru a window screen. This is a part of my soil/substrate for bonsai growing. I use lots of scoria but have tossed the fines in the garden for 20 years, then go and by grog and iron ox etc by the bag. Been wondering for a long time if could substitute this material for iron or manganese, or grog ? So we will find out soon right Link to comment Share on other sites More sharing options...
jrgpots Posted March 28, 2013 Author Report Share Posted March 28, 2013 I got about 5 gal of fines and ran part of the bucket through a 40 mesh sieve. I got tired after collecting about 4 lbs. I have two colors of the scoria. The first and the one I used for this experiment was red. The second color is black. I thought if I got good color with the red, I should get great color with the black. If it works I will be doing serial testing to find out the best ratio of scoria dust. I'll be glazing in the morning and firing in a few days. Hopefully we'll have color. I also want to try basalt glaze. The scoria is low in silica, so I was going to add a bit silica in addition to some bentonite and a flocculent. We'll see what happens. Link to comment Share on other sites More sharing options...
bigDave Posted March 29, 2013 Report Share Posted March 29, 2013 If it works, I'll post a pic. Cant wait Link to comment Share on other sites More sharing options...
AtomicAxe Posted March 29, 2013 Report Share Posted March 29, 2013 You make me want to test this. the fine grounds probably won't produce considerable speckling, and the particles you want to test with are going to be the particles between the 10 mesh and 40 mesh. Easy enough to do, just mesh 10 mesh first, then follow with 40 mesh, and what is left behind is your granular scoria, which not only should produce speckling, but also fluxing as it melts out of the body, which in minimal quantities should not affect the porousness of the clay if in small quantities, but could be interesting if embedded into the clay surface after throwing (sort of just sprinkled onto the clay when the slip is still present on the surface for example like ash flashing. the fine particles could be interesting in a slip, since it would not affect the clay body, but probably achieve your speckling if in substantial quantity without being lost inside the claybody itself. Link to comment Share on other sites More sharing options...
bigDave Posted March 30, 2013 Report Share Posted March 30, 2013 You make me want to test this. the fine grounds probably won't produce considerable speckling, and the particles you want to test with are going to be the particles between the 10 mesh and 40 mesh. Easy enough to do, just mesh 10 mesh first, then follow with 40 mesh, and what is left behind is your granular scoria, which not only should produce speckling, but also fluxing as it melts out of the body, which in minimal quantities should not affect the porousness of the clay if in small quantities, but could be interesting if embedded into the clay surface after throwing (sort of just sprinkled onto the clay when the slip is still present on the surface for example like ash flashing. the fine particles could be interesting in a slip, since it would not affect the clay body, but probably achieve your speckling if in substantial quantity without being lost inside the claybody itself. Good stuff A-Ax, thanks for the ideas, you seem to know about everything...good job Link to comment Share on other sites More sharing options...
jrgpots Posted April 10, 2013 Author Report Share Posted April 10, 2013 This is just an update on my project. 1. Laguna half and half clay body. 2. screened red scoria through a 40 mesh. 3. fully mixed 70 gm of this scoria dust to 1500 gm of the clay body. 4. bisque fired the bowl thrown with the mixed clay. 5. Glazed with Laguna oatmeal on 1/2, layered clear on the oatmeal as well as the raw bisque, leaving 1/3 unglazed. 6. fired to ^5. The clay body looks like "cookies and cream" and shows very nicely with a clear glaze. It did not interact much with the opaque oatmeal glaze. It should look nice under a celadon or other transparent glaze. I want to see what happens if I fire to ^6. Link to comment Share on other sites More sharing options...
bigDave Posted April 13, 2013 Report Share Posted April 13, 2013 The clay body looks like "cookies and cream" and shows very nicely with a clear glaze. It did not interact much with the opaque oatmeal glaze. It should look nice under a celadon or other transparent glaze. I want to see what happens if I fire to ^6. thanks JRG for the update. We had about the same results. 1st--I mixed about 10 % of scoria dust, stuff fell thru window screen, into laguna b mix. Where it was sponged ..cookies and cream otherwise,,,not. Cone 5 didnt even ome close to melting it 2nd bout the same in morrocan sand casting slip...smooth out side some scoria rose to surface inside....less than exciting Link to comment Share on other sites More sharing options...
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