We who are about to fire...

[eregel]

Wish me luck - just fired off my first ever annealling cycle. I'm going to stay in visual contact for the entire time it's running - REALLY nervous about doing this in the house. Going to clean my workroom and work on taxes - I figure the day is shot anyway, I may as well get THAT task out of the way!

Especially appropriate, since the tax refund is going to help with the shedio process, and once THAT'S done I won't have to run the kiln in the house any more...

Anyone know if I can run this without the ventilation running? It's 26 F out right now, and I'd really like to keep the heat in the house if I can! But I don't want to poison us.

[Eileen]

Exciting & scary, right?
I thought a large part of the ventilation was because of the propane and any metals in the melting glass, etc. but I'm not sure.

[krisdaka]

Smiling @ you Pat, your kiln is just hot box that goes on and off. No ventilation needed! You'll be toasty warm all day today!

[eregel]

It's up to 520, so still a long way to go, but I'm astounded how little heat it's giving off - I probably didn't actually need to trash my workroom to drag the kiln cart out into the middle of the room. But it's a good thing to know!

Once it turns off, how long to cool to room temp? I'm going to be like a kid at Christmas, wanting to see the finished product... It's an Aim 94BD, and the room temp is around 55 degrees - assuming it finishes up and turns off around 4pm, am I going to be able to open it up before bedtime? (my alarm goes off at 4am, so bed is usually pretty early - but if I have to, I'll be up til midnight tonight! I've got some experimental stuff in there that I'm DYING to see!)

[LarryC]

Once it turns off, how long to cool to room temp?

Depends on the program you are running. Did you enter it or did it come with the program from the manufacturer?

[eregel]

I entered it; it's going to hold half an hour at 800, then turn off.

[eregel]

Right now it's working on what should be a 2 hour ramp down to 800 - so far it's doing exactly what I told it to, which I suppose is a good thing.

[alb6094]

You'll be fine. :D It's scary right now but in a month (or less) you won't think twice about it.

[essiemessy]

:lol: Bless ya, Pat :love:
You're voicing what all of us were like back then (in my case, quite recently)!
If your kiln's anything like mine, it'll get nice and hot on the outside as well, eventually. I've proven bread dough on top of mine :lol:
It's been six months, and I still get a bit nervous.

[jaci]

I put a dented candle on the top of mine :)


bread!!! Too funny! (although I have thought about it! Lol)

[lorisue]

I may have missed something - but I was thinking that top temperature for annealing was 960/970 and hold for 1 hour.

or are those temps based on the type of kiln it is?

[Lyssa]

Pat, what type of glass are you using? What COE?

Just in case you need this info:

A common batch annealing schedule for COE 104 is:
Ramp up to (about) 925 at over 2 hours
Hold at 940 for .5 to 1.5 hours depending on size of work
Ramp down to 840 at 1 degree per minute
Hold at 840 for .5 to 1.5 hours depending on size of work
Ramp down to 600 or 700 over a couple hours and turn off. (The detail of this last step REALLY depends on the insulating abilities of your kiln.)

The goal here is to ramp up (slowly enough not to thermal shock your glass, I've done 4 degrees a minute, 10 degrees a minute, and "crazy fast") to a temp that is above the strain point of your particular COE and hold your glass there so it can soak soak soak all the heat in. Then you ramp down excruciatingly slowly (about 1 degree per minute) to your strain point (which is the lowest point that the molecules are still able to move but the glass is solid and won't droop), then hold it there for a while so the molecules in the glass can align themselves into happy states. Below the strain point you don't have to worry about introducing more stress into the glass, you just have to worry about thermal shocking the glass. Next, you ramp down from the strain point to a temp where you can turn off the kiln and your kiln's own insulating abilities can then take over ramping the temp down from there slowly enough not to thermal shock. That last ramping down should be about 4 degrees per minute. I can turn my kiln off at 400. I have a Short Guy from Glass Hive.

I've done a ton of research and the above is basically a working average of all the 104 COE annealing schedules I've seen over the last year, both on the web, here in the forums, from "trusted sources" like the people at Glass Hive, and from books, like Dunham's Creative Lampworking.

Hope this helps!

I may have missed something - but I was thinking that top temperature for annealing was 960/970 and hold for 1 hour.

or are those temps based on the type of kiln it is?

[Lyssa]

No Lori, those temps aren't based on the type of kiln used. It depends on the type of glass, and if you choose to go higher than the strain point, which is something most people do. The strain point of COE104 is 840, so TECHNICALLY if you wanted to hold the glass at 840 for a couple/three hours, you wouldn't need to go all the way up to the 900's. When batch annealing, the only reason to go up to the mid 900's is to sort of introduce insurance heat into the glass. I guess it's like a "just in case" the 840 temp isn't high enough, maybe?

Actually, I believe the REAL reason people do batch annealing schedules up to the 900's is because they are basing the batch annealing schedule on the production annealing schedule, which has you garage your glass at 940-960 so that when you open your kiln to put in more glass, the drop in temp doesn't go below the strain point and thermal shock all your glass into itty bitty fragments. I think people misinterpret the reason we use the mid 900's as our top temp, and think they need to do the same thing when batch annealing. But, since the real strain point for COE104 is 840, you really don't need to go above 840, if you trust that number and the thermometer/pyrometer in your kiln.

Hope this clarifies, but I get the feeling it's just as clear as mud. :)

I may have missed something - but I was thinking that top temperature for annealing was 960/970 and hold for 1 hour.

or are those temps based on the type of kiln it is?

[lorisue]

thanks Lyssa - you did clear up the "mud" a little better. I guess also that the setting I use on my kiln is pre-programmed so it saved me from trying to figure out those steps above and I just stayed with that every time. "when you find something that works - stick with it".

thanks again.

[eregel]

Just to ease people's minds - the full program I used ramped up to 940 over 2.5 hours, held at 940 for an hour, went down to 800 over 2 hours, held at 800 for another hour, then turned off. It took another hour to drop to 700, and 6 more before it was down to 94 -at which point I opened the dang thing, because it was LATE and I was impatient. LOL

I'm using 104, moretti and lauscha, with a little bit of DH and shards.

Some of the beads are in the Newbies gallery for February 20 - overall I'm pleased. I had one crack in half - but it had been only half-made when my torch ran out of fuel, so I'm not surprised.

And I had an experimental pair just outright fail - after seeing embedded cz I tried embedding some small Herkimer Diamonds (double-terminated quartz crystals - the mine at Herkimer is my Happy Place, and I have tons of small ones, was hoping I'd found a good use for them) That didn't go too well - they crackled, bad. Went from being gorgeous little crystals to looking like a pocket of diamond dust. But at least now I know! (Besides, it was a REAL pain insetting and encasing them! I'm kind of glad it didn't work!)

Exterior of the kiln never got hot enough to make me nervous - I certainly didn't have to worry about any spontaneous combustion. So it was all a huge success.

[artsyuno]

It probably is based, in part, on the type of kiln used. A brick kiln cools much more slowly (and heats more quickly) than a fiberboard kiln. You may not want to turn a fiberboard kiln off at 700 degrees. A brick kiln (like the AIM kiln Pat is using) can be turned off, because it will take several hours to cool to room temp.

[DeevaaS]

Congratulations, Pat!! My kiln sat in the box for weeks before I got the nerve to actually set it up and launch it. Well done!

[jaci]

I keep looking at the title of the thread and get the ACDC sone stuck in my hear "for those about to rock! We soooolute you!" :lol:

[eregel]

<grin> Actually I was thinking more gladiator "we who are about to die salute you" - but AC/DC works too! This lampwork stuff is funny - last night I had myself scared to death of my torch; this morning I had the absolute best torch session yet. Baby steps...

[jaci]

I love it when a torch session turns out amazing! Good for you!