Following on from the kind help I received on here, I treated myself to an SC2 with a bead door. I've been a bit nervous about firing it up, so I thought I would toast the new year by a 'simple' firing.
I followed all the instructions for a single speed firing. To be safe, I thought I would just dry some kiln wash on a fusing mould at a low temp rather than doing anything with glass at higher temps. I set it to go to 250 degrees C on full power and then hold at that temp for 15mins.
Anyway, the temp rapidly climbed to about 324 degrees C and I could see smoke coming out from the door (which was firmly shut). It then beeped a lot and the display briefly showed "14 mins" (not sure if that was how much time left or how much time it had had?) then switched between "HtdE" (High temperature deviation) and the temp, which gradually dropped down to less than 250.
I wasn't clear when it would have started timing the 15mins as the time didn't show on the display again. The instructions implied that if you press the down arrow, the rate, temp, hold etc will display one after the other, but firing will continue. Out of curiosity I pressed this and the "HtdE" changed to "Idle" and this continued to alternate with the temp, which kept dropping. I didn't get a "CPLt" message, but I knew at least 15mins had passed since it got above 250 degrees C, so I just switched it off and unplugged it.
This morning, this is what the inside of the kiln looked like:
(http://pic70.picturetrail.com/VOL1809/7783226/21234957/349419448.jpg)
And this is what the bead door looked like. I can't remember whether the inside of the bead door was white beforehand. It looks pretty brown/black now!
(http://pic70.picturetrail.com/VOL1809/7783226/21234957/349419446.jpg)
I realise having read previous threads that it was probably unwise to select full rate when aiming for such a low hold temp, but is anyone able to help me make sense of what happened please?
1) firstly, why did it burn inside and is this normal? I didn't vacuum the inside of the kiln before using as it was new. The outside of the kiln was covered in a white dust when I got it out of the box though. Have I ruined it?
2) What sort of rate should be selected for a hold temp of around 250 degrees C?
3) Once it had recognised the high temperature deviation, should it still have timed 15 mins for the hold time? I couldn't really work out whether it had just given up on the program completely after that as the temp kept dropping, I didn't see it stay around 250 degrees C for any length of time, and it didn't show that it had completed firing at any point.
4) Am I right in thinking that you can check the progress by pressing the down arrow during firing? When I did this, the display switched between "Idle" and the temp. Does "Idle" mean it has stopped working?
5) Does it matter that I turned it off in the middle of a program? I'm a bit scared of turning it back on again, but I'm desperate to put something glassy in there!
Sorry, about the long post. I probably just need some reassurance.
Thanks
All the best
Sam :)
Sam i am not an expert and someone else will help out more than me but it does not look major not sure about the technical stuff. The door and inside do get discoloured did you do an empty run before using it for the first time? I am sure Martin, Q or lee will be able to help you soon!
Hope it is ok!
Sam
Hi Sam,
Thanks for your reply. No I didn't do an empty run first. Should I have done? I suppose I thought that just putting a kiln shelf in without the glass was a sort of empty first run.
All the best
Sam :)
Doesn't it say to do an empty run with the plug out of the top of the kiln the first time? I vaguely remember something.
Ah yes I did not read that bit Doh!!!! Maybe that is the answer just kiln wash! maybe i am no help at all :-\I hope it is ok does not look to bad, my bead door is a brown colour!!!
yup
mine is brown too - i think it's ok
Mine had a lot of smoke coming out too - i think it's the burning away of the top layer - but alas not an expert
Thanks for your reassurance girls. Shirley, I have had another look through the manual, but I can't see anything obvious that says that the first run must be empty. I have to admit, I was a bit confused about the plug and when this should be left in the top and when it shouldn't. The manual gives some instruction about removing the plug for a period during fusing, but I wasn't sure what to do with it when drying kiln wash and I can't see anything about what you're supposed to do with it when annealing beads.
Its a steep learning curve. I'll be glad when I've mastered the basic use of the kiln.
All the best
Sam :)
It might have been a recommendation on here somewhere rather than in the manual, but I have definitely read somewhere about the first firing burning off any residue and the plug being out to allow it to escape. If I get a chance tomorrow I'll try to find the info :)
Thanks Shirley,
I appreciate that
Sam :)
Yep, I'm thinking the same as the others. I think the first fire can be a bit smelly and smoky but its not usually anything to worry about, and I think the discolouration is normal too. As for the Htde error, maybe if you're only going up to 250, you need to go a little slower?
And Idle just means its not running.
;D
Thanks Julie, that explains things. Presumably because of the overheating error, it just stopped the program then to cool down, I presume.
All the best
Sam :)
And don't panic if you get the overheating error. If I ramp my kiln up on full it always overheats, so I ramp it up more slowly and it's absolutely fine. It's the difference between putting your brakes on when you get to the cliff edge and putting them on early because you've seen the cliff edge coming. :D
Have a read of this thread. Great information on here
http://www.frit-happens.co.uk/forum/index.php?topic=861.15
I actually spoke to a guy from Paragon, and said it would be an idea to change their sample program in the handbook to one which doesn't lead to overshooting errors, but evidently they haven't!
i put off firing my kiln for the first time for ages!
i ran it empty with the bung out as it has to burn off "stuff" i had a panic and threw out the matt that came with it as it went brown, i have a tile in the bottom now,
i used a batch annealling program from on here and have just put in a bead as you go program, i have never used the preprogrammed ones on the kiln,
good luck,
sandy
Thanks Shirley, Kathryn and Sandy,
The other thread is very useful. Do you think it would be wise now to run it empty with the plug out?
All the best
Sam :)
I would do another test firing, but I think the plug in or out is immaterial. You will be using the plug in for annealing.
It will help you get used to the kiln if nothing else :)
Thanks for that advice Colette. Yes, I think I will be happier when I'm more familiar with using my kiln. I'm desperate to put some glass in there though!
All the best
Sam :)
you might find that some of the internal staining burns away over time, when I used silver clay i got a stain, but its not there now...I have some brown marks on the door, but it just looks rugged...who wants a kiln that looks like its never been used anyway ;D
I think the idea of having the plug out is so that whatever it was that stained the inside can escape. Best to have a window open too.
Thanks for the reassurance girls.
Well, I've just set it to run again without the plug in (and with the window open) at the 3rd speed, 555 degrees C per hr, and then to hold at this temp for 10 mins. If it all goes according to plan, I shall try another empty run to a much higher temp. I'm feeling a bit less stressed about turning it on this time :)
Lets hope it all works this time.
Thanks again to everyone for such great help.
Sam :)
Thanks everyone for such great reassurance and wonderful help over the last day or so.
I opened my kiln this morning to find that it was all beautifully white inside again. even the inside of the bead door was white again and I'm feeling a lot more confident using it now. The program ran according to plan. ;D ;D ;D
Do you think I need to do another empty run at higher temps before putting anything in, or should it be OK now?
Thanks loads. This is such a helpful forum.
All the best
Sam :)
I think you should be ok now. Have fun, and make sure you show the results :)
glad its all ok now, i worried sooo much about my kiln, now i wonder why ::)
the advice here is from experience and trial and error! always ask as there are some very talented people here who are always willing to share,
sandy
bless you - you must have got a fright and a half!! it does sayto do an empty run and to vent (but for a complete novice it doesn't fully explain what this is!) I needed a real idiots guide!
I had a look in our SC2 instructions last night but couldn't find anything! glad your kiln is working ok. I've had mine about 4-5 years On the inside cover of my instruction book on the digital controller on the SC2, it has firing temperature conversion tables with Fahrenheit and Celsius. Maybe you have one in yours
I have to say, I did get a bit of a fright and wondered if I'd get the courage to turn it on again.
I think I do need an idiot's guide. I've read the instructions twice now and I still can't find anything about doing an empty firing 1st. I'm very grateful for this forum.
Thanks Sea-thistle for the tip about temperature conversion tables. Unfortunately, my version of the SC2 didgital controller instructions doesn't seem to have this, but I have been recommended in another thread in the fusing section a link to look at.
I'll try and post what comes out of my kiln. Do people post disasters on here too?
Thanks everyone
love
Sam :)
you can google conversions of all sorts :)
Just remember if you use conversion tables that there are different ones for TEMPERATURE and RATE.
(so 500 degrees F converts to 260 C, but 500 F per hour converts to 278 C)
I am not sure how different the two are, but they are!
Already posted on another thread, but I have this page bookmarked for whenever I might need to check something:
Warm Glass Forum (http://www.warmglass.com/phpBB/index.php)
Can you change the output reading on your controller - I have a Skutt, which came in Fahrenheit, but I was able to change it to Centigrade (useful for slumping and fusing programs that I know in my head, but not so good when I want to try a program from a US site!)
my SC2 has the choice of either
Quote from: theseahorse on January 03, 2009, 11:33:20 PM
I'll try and post what comes out of my kiln. Do people post disasters on here too?
Yes and works in progress too because other people might help in diagnosing where I am going wrong when attempting something different.
Hi Seahorse, sorry for the late reply, had a very well earned 2 weeks off.
You seem to be sorted but anyway here goes.
The colour of the "burning" says to me that it is actually not burning but binder residue from the bead door. Many hard insulations are held together with binders, these tend to burn out the first time they are heated. If the kiln doesn't go high enough then the residue remains on the surface or the cool sections until the temperature gets high enough to remove them completely and the insulation will go white again. Hence why it is recommended to leave the plug out for the first fire I'd guess.
And yes, the lower the temperature set, the higher the risk of overshoot as the kiln will be rising quickly at low temperatures and will not just stop when the controller says so. Think of it as trying to stop a ship, you tell it wow....but the ship says no! ;D The faster it goes, the more it drifts on.
To avoid overshoot, just put a value of climb in for the controller to work to.
Thanks Colette, Dawn, Pat and Lee for your further thoughts,
It seems that my new SC2 does let you program in degrees C or Degrees F - but for some reason my brain can only cope with degrees C ::). I think I'm a metric girl at heart.
Thank you Lee for the useful explanation for the burning.
I'm happy to say, my kiln seems to be functioning and looking fine now. I've also managed to complete my first semi-successful attempt at fusing in it (pics posted in the fusing section).
Thanks again
Best wishes
Sam :) :)
Quote from: theseahorse on January 05, 2009, 11:16:36 PM
Thanks Colette, Dawn, Pat and Lee for your further thoughts,
It seems that my new SC2 does let you program in degrees C or Degrees F - but for some reason my brain can only cope with degrees C ::). I think I'm a metric girl at heart.
Sam :) :)
Sam, I am the same, I simply cannot get to grips with fahrenheit at all - even though I'm imperial with almost every other measurement! Freezing at O degrees just makes sense!
Yes me too, 0 degrees C works for me! Don't you just hate it when folk start talking about 56F - uh wot's that then? ;)