Sorry Diesel but the 14.8 (fourteen point eight) is the silica value to the 1 alumina, tried to say that above. There is no flux ratio up there besides the unity formula which IS the ratio of silica/alumina to 1 flux
The glaze is increasing in alumina and decreasing in flux towards the gloss.. Kaolin is 40% Alumina while my feldspar is 18% so removing the feldspar is not taking out more alumina that adding in kaolin gram for gram.
ok. That is just Si/Al ratio. The Silica value has a decimal place.
So after thinking for a bit, the unity is the ratio of flux to everything else!! I don't even know why I was working it out. It is always 1 flux to X everything else. I think you confused me a little but I am still amazed that less flux more alumina makes something melt. So amazed that I forgot how to think.
So I thought I slightly understood glaze chemistry. Been having a look at a few of my tests in more depth.
Here is a 'glaze' that is going from this very stoney matte to glossy with only really adding Kaolin
The bottom is the left table, middle middle and up right.
Thinks Kaolin = refractory stuff, so it wouldn't make something go glossy. All that really seems to be changing in the chemistry is the increasing Alumina, in non unity the silica hardly moves so I think that jump in unity value is because of the increase in alumina too.
All the flux going down, Al2O3 going up, SiO2 staying about the same. Less flux, more alumina = gloss. Very confusing.
When I turn up the kiln I am a fire breathing, ass kicking kiln god
There are far too many ways to go with this question as I think the definition of god is personal to everybody. My god/s is whatever 'stuff' the universe is, I am that god and can be part of the kiln gods crew. Rocks, water, heat are all doing their own godly things along with me. Different but exactly the same.
I have made an idol or personification of the kiln. It broke and then my kiln went out of action for many months, never made another one. Maybe now it is time.
A lot of risk assessment and safety rules are tailored to the lowest common denominator. One reason I will never ride a motorbike is because of everyone else on the road, I trust my own ability but not others. If I am alone in the studio then some rules will be overlooked because of the control I have over myself and my own reasoning of risk and reward. When other people become involved that's when I really start to worry about safety and wellbeing in the studio environment.
I had somebody in my studio who even though the kiln has a nice digital readout of the 1200c temperature and warned not to touch they just had to. Some singed fingers later and a lot of ice I think they were beginning to understand the dangers of hot kilns and just how warm they actually are.
Not sure how the meter does it but I am sure there is some voltage involved from the batteries to work out resistance. No need to have it plugged in and ON when testing out volts and your fingers far away from the metal ends.
You can get bogus reading sometimes, I was told it's a good idea to disconnect the neutral from the element if it is telling you something that seems way off.
You can test to see how far the elements resistance is away from brand new, just need to know what the brand new element resistance should be.
The elements in my kiln have a total resistance of 18 ohm so at 230-240 volts that gives me the 12-13 amps for the plug socket.
In theory it is VA for kw/h so 230 x 13 = 2.9-3.1 kw/h
Celia, I don't actually know the temperature the kiln gets to, never stuck a thermocouple in. All I have are the cones. I would like to go a little slower but the only switch for the kiln is at the plug socket. I would be interested to know the resistance on your elements and see if they match. Mine looked hardly used when I bought it.
I have only fired the kiln 4-5 times, nothing like the 4 years use so it could slow down. The biggest problem are the lids made out of fiber. Mine is so rusted but I think it sat out in the rain for a good while. I have seen many go through ebay with rusted lids so I think it has a few ventilation problems anyway.
Bought it for the idea to experiment with electric reduction but still haven't made it round to that yet For £67 I couldn't help myself.
I am maybe a little hard on the kiln but it can definitely get 1260 or a good cone 9
I have a very old rusty one exactly like that or an even older model. Had to gut all the electrics except the elements as they didn't work and I only have full power or no power but gets cone 9-10 happily in 6-7 hours. Definitely worth it for the right price as you get space for 12ish mugs, size depending.
Found a picture of some pots and the cones from I think a 6.5 hour firing. Maybe 7. Cone 10 is most of the way there. 9 and 8 very flat.