Twice as dense??

[SueP]

Enjoying reading this - Don't peek 

[Glyn Burton]

Remember Sabine that patience is a virtue and everything comes to those that wait-and also remember that if you live in Bolsterstone its always freezing, those are my cheery thoughts for the day.

[sparrow]

Still........

.......not.......

...........peeking.........

..........................

.......must..................

..............................resist....................

Lol, Glyn, you're right. We have the heating on, and I'm under a blanket with a hot water bottle......

[Lilley]

Oooh I so feel for you - I am bad at waiting too.....  but I do wait, mostly by firing the kiln overnight such that it will be cold by the morning, but definately too hot to go even thinking about opening it before bed that way I don't notice the waiting soo much - but it does mean I bring my tea out to the studio in my dressing gown and slippers all too often  (probably not a good sight first thing in the morning!  )  It's on its way down as I type, but is at 400C and cooling at 100C/hr.

[Flyingcheesetoastie]

I've had to adjust my speeds both up and down due to the winter weather and my studio is inside a big concrete block of a building. I had my first cracked piece in the kiln in years the other week and it was purely due to going up to quickly. I mainly use float too Sabine so I'm not judging the economics of it. I use 4mm for dishes and clocks, 10mm for hares and other water jet cut bits. The thicker pieces I ramp at about 250c/hr to 500 then full to whatever paint firing I'm doing. Cooling its more like 45c/hr from annealing to 50c and even then don't peek till its at room temp.

[sparrow]

Right.....experiment two didn't crack....but it also didn't do what I wanted. Re-started the kiln with attempt no. 3 at 7am this morning, adjusting a bit here and there Very, very slowly, I'm beginning to understand the point behind different ramps, temps and holds, and feeling confident to tweak a titchy bit - thanks for all the help!

[Zeldazog]

I've had to adjust my speeds both up and down due to the winter weather and my studio is inside a big concrete block of a building.

A timely reminder for me to check my schedules, and no peeking early... it's the first winter for Kiln Bill and the studio got so ridiculously cold at times last year....

[sparrow]

Sooo....would I be right in thinking that winter schedules work in summer (but would simply take longer), but summer schedules might crack in winter? Or is that oversimplifying it? I'm getting my big kiln soon (hopefully tomorrow), so I guess I'll start out on winter schedules It'll be stood against the outside wall of the garage  studio (only place it fits!)

[Zeldazog]

Yeah I'd say so Sabine - to be honest, I don't usually adjust for winter, but Bill arrived when it was spring, so I may need to slow stuff down....  once I have done that, I will probably leave him be, I tend to fire conservatively anyway - only thing lost is a few hours production time, but it will still be done when I get there as I don't do silly hours at my studio (unlike Rachel!)

[sparrow]

Thanks, that would work for me too, I think - it'll be a long time before I have the confidence to mess too much, so if I get something that works in December, I think I'll stick with it 

[Flyingcheesetoastie]

Silly hours?  Dunno what you mean, I've only had a few times where I've been there at 1am!  But yeah I am in and firing at least one kiln every day mostly.  The best idea I had and can recommend is to have a wall themometer above your kiln, not so close that the heat coming off it will effect it but so that you have the actual room temperature to eye when you programme.  Also it's good to note the temperature inside the kiln if you've not fired it recently and it's cold, if it's reading below 10, then remember that it's got to heat that cold air, the bricks, the thermocouple, any props etc before the glass, so go easy ont eh poor wee thing!

To be honest, I probably change something with every single firing I put on, but that comes from practice and confidence/arrogance that you know what will happen!  I probably should start writing some of the generalisations down, but it varies from kiln to kiln anyway!

[Pat from Canvey]

Dawn, I have to comment on your new avatar. DH is a Clangers fan.

[sparrow]

Well......it didn't crack, and it did pretty much what I wanted it to. Now I need to design it properly with colours and such things, lol!

[flame n fuse]

Following the conversation about winter and summer firings above, most kilns are programmed to heat up by so many degrees per hour, to a particular temp, so I don't see why the outside temp matters too much on the heat up - if it starts colder, it'll just take longer.  It might matter on the cool down, if you have a cooling segment which is AFAP, if your kiln isn't well insulated.

[Magpie]

Not that I know anything about fusing, but if the glass starts out colder and the kiln heats quicker as the air will heat faster than the glass there will be a greater difference in temperature between the inside of the glass and the outside, possibly leading to a greater possibility of cracking, depending on how thick the glass is that you're playing with.

Back to the original suggestion. Scientifically if the same amount of glass is twice as dense, surely it would be half the size, so unless you've got a magically multiplying kiln by the time you've fired it 3 or 4 times it would be hard to find unless it was massive in the first place.