Boro Annealing Schedule Questions

[Tink]

I'm using primarily GA colors, some of which benefit from kiln striking. What is the best conservative annealing schedule that includes kiln striking? And can someone translate it to Fuji controller language for me? That would be:

Target Temp
How long should it take to ramp to that temp
How long should the kiln hold at that temp

I'm guessing three segments? Set point of 1050. Hold for how long after the last piece goes in? Striking temp, rate and hold. Then back down through the strain point, rate and hold. Then down to room temp, rate.

I have a toolbox annealer, so I want to make sure that final drop to room temp is managed and not just a crash.

[Cosmo]

It depends on the color. I like to strike reds lower and for longer. Usually 1000 degrees for 4 hours or more. Purples I strike pretty high. 1100 for 30 minutes. Higher if you can get away with it. I do have better luck with purples striking them right after I put them into the kiln, then holding at 1050, rather than holding them and then striking. For greens and blues, I have found that once they are flame struck, you see very little change from kiln striking, so I just hold them at 1050.

For boro, you can raise it up to target temp at full speed. I do that with pieces up to 1" thick with no problems. Larger pieces I do slower (usually 1000 deg/hour). I have never had a problem with up to 3" marbles cracking that way. 3" is as large as I can do. I always hold at temperature for 2 hours per 1" thickness (although I have heard 1 hour is long enough).

I ramp them down to 960 at 1000 degrees/hour, then I let mine go down to room temp at full speed, but my kiln is brick, so with a fiber blanket kiln, I would think ramping them down at 1000 degrees/hour would be sufficient, but I don't have experience with a fiber blanket kiln, so I can't say for sure. I know Brent has one now, so he'll probably chime in soon and tell you for sure.

[CarolinaDreamDesigns]

Any other comments on this? I am starting boro and have a Chili Pepper so I'm not sure what the correct ramp down cycle is. I'm not sure where I got this but : I take the kiln to 1075, let it sit there while I'm playing (rubies last), then soak an additional 1.5-2 hrs after my last bead. It ramps down at 100 degrees an hour until it is at 100 then off. Do I need that hold time in between?

thanks!

Martha

[Over the Moon]

You can "garage" happily at anywhere from about 1000 to 1050, then when you are done for the day you can ramp up to anywhere from 1075 and up for 1/2 hour to 3-4 hours, then ramp down at 85 degrees/hour to 960. Hold 30 minutes, then turn off.

[CarolinaDreamDesigns]

thanks but if I'm on a Chili Pepper kiln - not a brick kiln - don't I need to control the cool down more?

thanks!

Martha

[HardwoodTrailGlass]

thanks but if I'm on a Chili Pepper kiln - not a brick kiln - don't I need to control the cool down more?

thanks!

Martha

Hi Martha, I also have a Chili Pepper and I am happy, w/ my schedule which is roughly what Val wrote. I do shut it off after holding at 960. I make mostly beads and a few larger pendants. I don't make marbles and nothing anywhere close to 1" thick.
Maybe Smiley will chime in, he uses a Chili Pepper too. :biggrin: He obviously has way more experience than I do.

[Mr. Smiley]

I work with colors that like to soak at about 1075 and will strike at that temp. My schedule only has two segments. A hold at 1075-1085 and a ramp down to 960 at 60 degrees an hour, hold for 20-30 minutes. Then it turns off. For smaller work there is no reason to hold or ramp slower after the strain point. If you want to have a 3 segment schedule, I'd follow Val's advise. She's dead on. ;) Chad has some good advise for reds, but I'd go a bit higher for a little bit. I also use Elvis and it plays nicely at 1050. :lol:

[HardwoodTrailGlass]

Thank you Smiley for chiming in! :)

[CarolinaDreamDesigns]

thanks everyone!!! now I just have to go chant while I reprogram to keep track of everything ... first is ....

:-D

Martha

[RuskinDesigns]

It depends on the color. I like to strike reds lower and for longer. Usually 1000 degrees for 4 hours or more. Purples I strike pretty high. 1100 for 30 minutes. Higher if you can get away with it. I do have better luck with purples striking them right after I put them into the kiln, then holding at 1050, rather than holding them and then striking. For greens and blues, I have found that once they are flame struck, you see very little change from kiln striking, so I just hold them at 1050.

For boro, you can raise it up to target temp at full speed. I do that with pieces up to 1" thick with no problems. Larger pieces I do slower (usually 1000 deg/hour). I have never had a problem with up to 3" marbles cracking that way. 3" is as large as I can do. I always hold at temperature for 2 hours per 1" thickness (although I have heard 1 hour is long enough).

I ramp them down to 960 at 1000 degrees/hour, then I let mine go down to room temp at full speed, but my kiln is brick, so with a fiber blanket kiln, I would think ramping them down at 1000 degrees/hour would be sufficient, but I don't have experience with a fiber blanket kiln, so I can't say for sure. I know Brent has one now, so he'll probably chime in soon and tell you for sure.

OK - I am denser than most :). If I was to batch anneal with boro I could put hearts, beads and implosion pendants in cold and ramp up full speed without damaging my glass?

I am not sure what my problem is - I have always batch annealed and I am just chicken to turn the kiln on first - do we get denser with age?

[Cosmo]

That's what I do. If you are nervous about doing that, then ramp it up slower. But, I haven't lost any ramping them up at full speed.

If I'm heating something larger, like a big marble or something I'm going to rework, I heat it up slower. But for small things, it's full speed ahead, captain...

[Mr. Smiley]

I agree, full speed ahead for me too. :D

[baylie]

3" is as large as I can do. I always hold at temperature for 2 hours per 1" thickness (although I have heard 1 hour is long enough).

I ramp them down to 960 at 1000 degrees/hour, then I let mine go down to room temp at full speed, but my kiln is brick, so with a fiber blanket kiln, I would think ramping them down at 1000 degrees/hour would be sufficient, but I don't have experience with a fiber blanket kiln, so I can't say for sure. I know Brent has one now, so he'll probably chime in soon and tell you for sure.
Henry at GA told me at least 15 minutes at strain point per 1/4 inch of thickness.At least. I use this as a rule of thumb(insert boondock saints reference here) with most of my stuff.
Cosmo, don't limit yerself, I didn't think I could pull marbles any larger than 2 1/2 inches on my cc, and i busted out much larger stuff since then. I takes forthought and practice. I have faith that you can go bigger, just make sure and hydrate.hahaha

[gennym]

The only (consistent) luck I have with striking colors is to ramp up to 1150 for 30 min (after "garaging" at 975) and then go back to 1050. I guess I would say the torch/kiln temperature questions have been the greatest source of stress for me - real hair pulling days!

[Mr. Smiley]

Welcome to boro. It really depends on the kiln too. I tend to strike on the lower end (the range for AP is 1075-1200) for longer periods. If I have a piece or two that need to go in again, they can. This gives me more control... but there is no wrong way to get color, as long as you're hitting an annealing temp and soaking long enough to relieve the stress. :D

[Starrr]

I'm just getting around to playing with my boro, (yes Brent, I STILL haven't played much with all the boro I bought from you! LOL).

Can I do this?.... My kiln is a FuseboxII and pre-programmed for soft glass to soak at 960. If I raise the soaking temp to 1050, (correct?), make my boro beads, drop down to 960 and make soft glass beads, then when I'm done for the day can I run them all together through the same annealing schedule?

Schedule is:
soak at 960 for 1 hour
drop to 860 for 1 hour
drop to 760 for 1 hour
then drop to 500 and turn off
I never open my kiln until it reaches 100

Will this be okay?

Edie

[Mr. Smiley]

Edie. It will be fine to crash it from 1050 to 960, if you don't plan on calling them annealed. If you want them to be annealed, go a bit slower... like 70 degrees an hour (make a snadwich and watch a show). Then you'll be fine. If you're going to kiln strike any of the Amber Purples, you'll want to bump it up to 1075-1085. ;)

Have fun and keep it hot! :love:

[Starrr]

Thanks Brent, I'll just ramp them down to 960 slower, I'm sure I can find something to do in between.

Edie