Hello, I know threads like this have been started of this nature in the past but I am at my wits end! - I have today made some lovely beads (following my visit to Mango Beads yesterday ;D) however they went into the Kiln Round and have come out oval! - This is only the encased ones though!!! ???
I have been round in circles on FH trying to find an annealing schedule for my SC2 (they do seem to vary) and have found this one which is in a tutorial... does this look good to try?
Ramp1 FULL
Temp1 510 C (garaging temp)
Hold1 6.00 (Dependant on "Beading" time)
Ramp2 FULL
Temp2 520C (annealing temp)
Hold2 60mins
Ramp3 50 C
Temp3 371 C
Hold3 0.00
Ramp4 0000
I am not sure at the moment what mine is set on, but obviously it is incorrect, I don't want to mess with it at the moment as I have warm beads still in there.. (Even if they are oval ones!!) >:(
Any advice is greatly appreciated, I have managed to get my encasing perfect today (Thank you to watching Manda yesterday and taking some "Patience" advice away with me!) for the first time and I am really dissapoionted now!
Help! :-[
When you say oval do you mean egg shaped, where the glass has visibly drooped due to gravity?
Thats it! :( - but they weren't tacky when they went in!
Right, and it was only the encased beads? Did you have other beads in there as well unencased?
I don't know how to program an SC2, so I can't help with that, but what temperature is your digital read out saying that the kiln is getting to?
It could simply be a matter of it's programmed to go too hot? /What schedule are you currently using?
One thing to always remember is that all kilns are slightly different - even two kilns, the same model, etc, will vary. Just because a kiln says it's at 520 degrees, it could be somewhere away from that, and as kilns get older, the thermocouple can become less accurate - so giving a false reading of the actual temperature. This is why is important to get to know your own kiln, even for bead annealing (just look at the research done for maxi/maxine on here to see how it has different heat zones)
Hi, yes, but they weren't as big! - not that the encased ones are huge!
Sorry I didn't see the bit about it being encased only.
No problem any advice is welcome.. I have just started to encase with the new Lausha soft, will that make a difference do you think?
It is odd that only the encased beads are drooping, this suggests to me that the kiln is fine but its something to do with either you or the glass....for example, you are checking the encased beads for a bit too long before they go into the kiln and they are drooping without you realising or the kiln is too hot for the specific glass.
several other people have replied whilst I did my slow two finger touch, but i'll jump in anyway ::) ;D
Hiya,
The annealing schedule you list looks very good - it's even on the conservative side, which is the safest way.
The only thing I would say is that some silver glasses lose their reduction if they are annealed at a temperature too high. After I found out I started garaging at 500 deg C, and annealing at 510 deg C (otherwise the same as in your schedule above).
Some people recommend annealing at as low as 470 deg C. I have a feeling that my SC2 shows a bit higher temperature than it actually is, and have found that the shine is still there after annealing at 510 deg C, so I have kept it at that temperature.
Your oval beads indicates i) that the temperature in the kiln is too high, or ii) that you don't let the bead cool enough before putting it in the kiln.
I normally swirl the bead in and out of the top of the flame until it stops glowing before putting it in the kiln. This allows the core to cool whilst still keeping the surface layer warm, i.e. evening out the temperature in the whole bead. It also insures that the bead doesn't stick to anything already in the kiln, whether it be another bead or the kiln shelf/floor.
HTH! :)
Quote from: Tills on October 12, 2010, 05:30:07 PM
No problem any advice is welcome.. I have just started to encase with the new Lausha soft, will that make a difference do you think?
I'm not a beaderer, but from a fusing point of view, even though (Bullseye for example) a range of glass are compatible for fusing, some colours soften earlier than others.
Thank you Both, I have just taken all the beads out and had a look, the major "drooper" is the larger of the encased beads, perhaps I did put it in too hot, the others don't seem quite as bad although there seems to be a slight droop (can't be doing with droop ;))
Just checked my schedule which was given to me about 12 months ago:
RA1 Full (530c)
Hld1 6 hours (I always allow an extra hour for annealing, someone gave me this advice ages ago :-\)
RA2 222 (371c)
Hld2 0 - The hour is included above
Is this good or bad?
I won't be offended honest! ;)
Firstly, I have Lauscha soft, and have never had any problem with drooping/slumping.
I think you should adopt the schedule in your first post - the one you are using is annealing at quite a high temperature, and it cools down too fast through the annealing schedule.
Thank you all and Julie yes I will give it a try :)
I'd agree with Julie, that cools down WAY too fast for annealing.
Quote from: Tills on October 12, 2010, 05:20:16 PM
Ramp1 FULL
Temp1 510 C (garaging temp)
Hold1 6.00 (Dependant on "Beading" time)
Ramp2 FULL
Temp2 520C (annealing temp)
Hold2 60mins
Ramp3 50 C
Temp3 371 C
Hold3 0.00
Ramp4 0000
That looks the same as the schedule I use with my SC2. The onloy problem I've found is that if I programme 'full' it overshoots the temperature by quite an amount so I changed 'full' to something like '700' and it's pretty well spot on now, just takes a bit longer to get to temperature but not much longer. So far so good, none of my beads have drooped, sagged or anything else strange, although that might improve a few!
I agree, the SC2 can overshoot horrendously on full. You can wait for it to get to temp, watch the overshoot happen then wait for it to come back down again, and as others have said make sure the outer layer of your bead isn't too warm before you park it in the garage :D
Brilliant, thank you I will use the advice when next at the torch!
Suggest you anneal at 513 DegC, only go hotter if you need the temperature to strike special colours. I ramp up slowly to prevent overshooting. Also ramp down very slowly to below the strain point (Around 440 for bullseye, 460 for effetre).
I use the same program for all soda glass (bullseye, effetre, plowdens 93, reichenbach):
250/hour up to 513
Hold 60 minutes
40/hour down to 420
250/hour down to Ambient (My kiln wont cool this fast.)
Be careful not to mix up stress-relief point and strain-point they are often confused on internet posts. The stress releif point is the annealing temperature where the molecules can freely move but the glass wont deform (much). The strain point is where the glass has effectivly set and the molecules will stay in position, only below this temperature can the glass be cooled quicker. Dont open the kiln, even below the strain point, a sudden ingress of cold air could thermal shock the glass and cause breakage.
Annealing boro is very different, I use the recommended schedule from NorthStar which uses a series of steps to cool.
It seems that here in germany is a different annealing schedule! ;D
My (and many others) program:
Ramp1 FULL
Temp1 510 C
Hold1 6.00 (Dependant on "Beading" time)
Ramp2 FULL
Temp2 510C
Hold2 60mins for big ones, 30mins for smaller ones
Ramp3 35 C
Temp3 440 C
Hold3 60mins for big ones, 30mins for smaller ones
Ramp4 0000
Tis a strange one - I anneal normally at 520° - but fir striking glass I go to 545° and even when I've put in softer coloours at the 545 temp (white and ivory) they've been fine!
Stick to the first schedule I'd say!
Stuart, I don't know about the other soda glass makes, but your cool down stops rather soon for all the information I have for Bullseye - they recommend a controlled cool down to 371 centigrade on fusing glass and I would have thought it is similar for beads
(that said, your cool down is more conservative, I usually go through the annealing zone, 517 to 371 at 83 degrees per hour)