My first Batch Annealing

Harry · #1 2011-10-14, 12:20pm

Hi lovely board. I got my kiln last night and of course immediately pulled it out of the box and set it up (with a fountain of packing peanuts I might add). I will try my first annealing tonight but before I do I wanted to see whether my plan sounds sound to you

Here it is:

1. I will take the empty kiln up to a descent temperature to get rid of anything volatile that might be left over from the manufacturing process.

2. I will put the beads into the kiln and will gradually bring it up to about 950 F. I will keep it there for just a few minutes, then I'll turn the kiln off.

3. I am planning on leaving it closed to cool slowly over night. I figure that way the insulation will work its magic and everything will cool at the same rate.

How does that sound? BTW, the kiln has a conical hole in the side of the chamber that is to be plugged up by a ceramic cone. Any idea what that is for? I'm assuming it's not a peep hole unless you want your eye barbecued.

Harry

lorisue · #2 2011-10-14, 12:48pm

Hi Harry - I'm not sure what kind of kiln you have, but did it come with a manual on setting up for batch annealing?

I have a chili pepper and it has a pre-programmed setting for batch. I load it up and run the program. it ramps up to temp, sets for 30 minutes (I think) then starts reduction. I don't do anything the entire time.

BrownGirl · #3 2011-10-14, 12:49pm

Hey, Harry! How exciting! I don't know the specifics about your kiln but this is what I was told about my glasshive kiln...

I was told to run it through one complete cycle to "burn out" the crud. I did that. It was a little stinky but every other cycle i have run it through since, there has been very little to no stink.

I was also told that you shouldn't turn off your kiln until it's below 700 degrees. At that point you can shut it off and let it cool slowly and go to bed to wake up to wonderful goodies.

As far as batch annealing, I put all my beads in the kiln, then turned it on, let it get up to temp and let it sit there while I made more beads. When I was finished, I ran he program and everything seemed fine.

Now, I am a newb so, I am no expert by any means. I am only going by what I have gotten as answers when I asked.

Good luck and say hi to your new friend!

Lisi · #4 2011-10-14, 12:49pm

Harry,

I am assuming by the first sentence you mean that you are going to let it cool completely after this first step, before you put the beads in right? The kiln has to be at room temperature to put them in for the batch annealing.

Once you place them in and ramp up slowly, then you must leave the kiln's temp at 950 to "soak" (hold) for an hour. Then ramp down slow to 840 which is the glass strain point and hold (soak) that temp for 30 minutes. Then ramp down slow to about 700 and shut off. This is a brick kiln, am I right? Brick kilns are great because you can shut off at a higher temp than the ceramic fiber kilns. When you are done with your strain point hold and ramp down to the shut off temp, then just leave alone for the next 6-8 hours until it cools to room temp.

You have an infinite switch and pyrometer set-up with this one, and not a digital, right? Sorry about the questions because I may have missed the info in your earlier threads.

glasshobbit · #5 2011-10-14, 1:02pm

Peephole is to vent the kiln or to take a peek. Generally used when fusing or slumping glass. Can't think of a good reason to use it when doing beads.

Holly · #6 2011-10-14, 1:43pm

You have a manual digital controller?
Here's a batch annealing schedule for 104 coe:

800°/hr (F) to 350°
Hold 5 minutes
800/hr to 500°
Hold 5 minutes
800°/hr to 750°
Hold 5 minutes
800°/hr to 968°
Hold 30 minutes
Ramp down to 840° over two hours
Hold for 10 minutes

I have a dental burnout kiln with a manual digital controller and this is the schedule I use. If I am using special glass (like silver glass) I only go up to 925° and hold for an hour instead of 30 minutes. It's about six hours total time. I then ramp down at 100°/hr until it reaches 100° then turn it off (this is usually overnight and I turn it off when I get up).
If you have the test kiln the peephole may be to see if the cones are melted (used in firing pottery).
When loading the kiln, I place the beads on a piece of fiber cloth and never let them touch. At 968° the beads can get stuck to each other but not the fiber.

misspiggy · #7 2011-10-14, 3:20pm

Sounds like you are gonna have fun with your new kiln.
I think everyone has slightly different schedules and temps set up on their kilns. I have mine set to go up to 960 for 30min for batch. I think it might make your life a little easier if you have a digital controller? But I don't know since I never had a kiln without one.
As for the "peanuts" that came with your pkg. You can bring them to your local UPS stores and they will recycle them for you.
Have fun!

Harry · #8 2011-10-14, 4:05pm

I think I'm starting to realize why a digital controller is such a big thing. Mine doesn't so I'll have to spend the evening messing with it. right now I'm establishing what setting equates to what temperature. Thanks for the info. I'll adjust my plan accordingly. How would I know whether I have brick or fiber? It looks like really light brick, almost like pumice.

H

Lisi · #9 2011-10-14, 5:06pm

Quote:

Originally Posted by Harry

I think I'm starting to realize why a digital controller is such a big thing. Mine doesn't so I'll have to spend the evening messing with it. right now I'm establishing what setting equates to what temperature. Thanks for the info. I'll adjust my plan accordingly. How would I know whether I have brick or fiber? It looks like really light brick, almost like pumice.

H

That's brick all right, and it's very lightweight and even a bit fragile. But the metal housing holds everything together so no worries. I've had my Paragon for nine years.

The fiber blanket lined kilns look like a cotton material but it's finely spun ceramic fibers. A real hazard for your lungs, but it does make a nice lightweight kiln. I believe the fiber lining for those types of kilns are treated with a substance that keeps the fibers together, not sure.

Babysitting a kiln without the digital controls can be a pain to some, but hey, congrats...you're annealing!

Harry · #10 2011-10-14, 9:05pm

I'm just letting it cool. My manual says I can turn off the kiln and unplug it at 1100 so I brought it up to about 1100 and now I'm letting it cool down. I'll take the beads out tomorrow morning. I'm curious whether 1100 was too high.

H

Lisi · #11 2011-10-14, 10:30pm

Quote:

Originally Posted by Harry

I'm just letting it cool. My manual says I can turn off the kiln and unplug it at 1100 so I brought it up to about 1100 and now I'm letting it cool down. I'll take the beads out tomorrow morning. I'm curious whether 1100 was too high.

H

Yikes!! They probably have slumped because I think Effetre melts at 1400, I'm not sure of the exact temp. That's why I asked if you were doing the burnout and letting it cool first before placing beads in to anneal. Did you have kiln wash on the floor of the kiln, I hope??

28676bhe · #12 2011-10-14, 11:03pm

The hole is for ventilation when you're using toxic or stinky materials. You will want to fill in the hole with a plug, or roll up some used fiber paper.

Be very careful on the way up and on the way down. I don't take my kiln over 200 degrees per hour to 965.

Holly has given you good advice in stopping every few hundred degrees. These holds will allow all the glass that is in there to achieve the same temperature throughout.

Barbara

Dale M. · #13 2011-10-15, 7:01am

I think 1100 is way to hot.... I had problems going over 990 of beads beginning to slum and my pyrometer is calibrated...

A test of kiln temperatures is to take a length of rod, support it on two heat proof objects and take kiln up to annealing temp.... If rod sags your temperature is to hot.... Either your pyrometer is not accurate or you are using the wrong annealing temps/schedules for your glass type...

What I do (and its a pain) with kiln with infinite controller is take beads up to 968°f. in about a 2 hour stretch, hold beads at 968°f. about 45min to heat soak them, then drop them to 840°f. (strain point) and over next hour and hold them there for about 30-45min, the drop over next two hours (or so) to about 400° and turn kiln off and let kiln cool overnight, only because I'm down to around 400°f. at about time for "lights out" and I can wait till next morning to inspect...

Really the only difference in batch annealing and "garaging" then annealing is the ramp up time... With garaging you can get kiln there as fast as it can go.... With batch annealing you have to allow for glass in kiln to transfer heat thoroughly to core of glass item(s) and this take about 2 hours for average bread... I believe the accepted ramp up for batch annealing is about 30-45 min for ever 1/4 inch of glass thickness of object in kiln...

Once kiln has reached annealing temps, the ramp down times (cooling) is same for batch annealing and garaging then annealing....

Dale

LarryC · #14 2011-10-15, 7:59am

Quote:

Originally Posted by Harry

I think I'm starting to realize why a digital controller is such a big thing. Mine doesn't so I'll have to spend the evening messing with it. right now I'm establishing what setting equates to what temperature. Thanks for the info. I'll adjust my plan accordingly. How would I know whether I have brick or fiber? It looks like really light brick, almost like pumice.

H

Sounds like soft firebrick. Your learning right now but soon you will want a digital controller. It is so much less work and so much more accurate and consistent to just program a digital hit the button and walk away. Your learning