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Showing results for tags 'cones'.
bubbly.pdf Hello, hi ! I've been a bit lost and what seems to be a loop when looking to re-create this glaze somehow. I'm pretty fresh to pottery, and am willing to take any and all information to help me understand what creates this effect and if this piece is done by using two different types of glazes. For example a white over gray glaze with a higher levels of iron oxide? Thank you kindly
Hello! I have a question regarding what cones my kiln is able to fire to. I’m using a manual skutt 1227 that hasn’t been used in approximately 4yrs. I am a school teacher and have been told this kiln has been at the school since 1996. I have successfully fired the kiln up to cone 04 with low fire clay and glazes. Today I tried to fire some cone 6 clay/glazes, but after about 9.5 hrs on high the kiln still had not reached cone 6 temps. Could this be a problem of needing new elements? Or something more complex?
I have been trying to be scientific about arranging my firing schedule in a small electric kiln with a controller. I understand the concept of heatwork and use cones on all shelves in my kiln to monitor results. I soak at top temperature and fire down so want to compensate for the additional heatwork these procedures involve when I set the top temperature on my controller. I understood that this could be done by looking at the area under a graph of total heatwork, but having compared theoretical models using the Orton cone firing tables, if this is indeed the case, I must be missing something. The following example uses °C, as I am in the UK, and I am referring to the Orton theoretical temperature values. 1. In the Orton table Cone 7 is reached at 1237°C when firing at 60°C /hr, if this is a straight ramp, this would take 20.3hrs, assuming a starting room temp of 17°C ((1237-17)/60). If the x-axis is time and the y-axis temperature, the area under the graph is a triangle and can be calculated as (1237 x 20.3)/2 = 12,555 2. When firing at 150°C/hr cone 7 is reached at 1255°C. As a straight ramp this would take 8.25hrs ((1255-17)/150). Then the area under the graph is also a triangle calculated as (1255x8.25)/2 = 5179 SO, these areas which are supposed to represent total heatwork to achieve cone 7 are not the same. I am clearly missing something here. Can anyone help please. Thank you