Does anyone batch anneal boro

[Renee Weaver]

Hi! I have had wonderful help from Bunyip on working with Boro for the first time. Thank you, Thank you! But I need some help still. Does anyone batch anneal? I have a big kiln, 17" by 9" by paragon with a digital controller, I did fusing once upon a time.
Im getting almost black beads. I've thrown away probably 300 beads.
They look pretty good going in and so terrible coming out. I am running a schedule of full to 1080, hold for 30 minutes, ramp down 60 degrees per hour to 960 and off. I put a DAP rod in the kiln and it turned out a VERY dark amber red. Is batch annealing just not going to work?
Help!
Renee

[elle]

Try bumping that annealing temp down 20 degrees and see what happens. And 960 is at the higher end of the strain point for boro... I would wait until at least 800 to turn the kiln off. I'm assuming it's all firebrick?

Sarah

[pipyr]

I used to batch anneal all the time...no problems I'm wondering if your kiln is running a higher temp than you think it is...I don't seem to get any additional striking when I'm just at annealing temps. If I want to strike something in the kiln, I always bring it up over 1200. My guess is your temp is off...you shouldn't be getting those colors at 1080. Someone correct me if I'm wrong??

[Norskiglass]

Well I run mine @ 1050 and 1125 for kiln striking. the mechanical stress level is abouve 500 degrees. I have seen people just open up the kiln @ 500 (not good idea) but after all if you make it right boro is not going to be so reliant on the kiln.....its on the bench and how you work it What type of color is this you are working with? Pm me if you like.......~G'day!

~W~

[ShepherdCreations]

We batch anneal our boro at 1050. No color changes at all, what you see going in is what comes out. I like to flame strike. We ramp down (and by we i mean my husband, lol) 25 degrees for every 10 mins after they have been soaking. He turns it off at 700 degrees and we don't open it after that. It usually works for us! Good luck with yours, a lower temp might be better for you.

[Renee Weaver]

I am working with DAP encased. I'm so glad that there are people that batch anneal! That means that eventually I should be able to figure this out. I tried running some beads through at 1000 and I got the same dark tea color. I am flame annealing a bit until I see some color. Some of them I get so excited about because I see a little bit of some pretty colors start to show. Stick them in the kiln,...wait...wait forever... run and open the kiln up when the temp. is under 200 degrees. And.... ugh, dark tea colored beads. The way this has been going, I'll be striking at 800 degrees. LOL Wow, my kiln must be an over -achiever! I have been using this kiln and digital controller with my soft beads for 5 years and have never had melted beads or anything. Should I put a piece of a rod in, set my controller at different temps, until I find what temp doesn't change the rod? If I can find that temp, how will I figure out an annealing temp schedule? Sheesh, boro is hard enough to figure out without having a kiln from hell. Any suggestions? Maybe I should just buy a new bead kiln.

[elle]

My pyrometer is definitely off. I always batch anneal my boro at what my pyrometer reads as 1000, but I know it's much hotter than that. I discovered that the hard way when everything turned black and ugly at 1050! I suspect it reads at least 75 degrees lower than it actually is, and I had to do several test cycles to figure out what temperature adjustment I needed to make. This is just one of the many reasons two people can't get the exact same results with boro.

Are you going up to full temp right off the bat when batch annealing? If so, that might be too fast, depending on how long it takes your kiln to reach the target temp. (this may even be part of your problem, but don't quote me on that, as I'm totally guessing.) I take about 3-4 hours from room temp to annealing temp, ie, a slow and gentle ramp up. It may be boro, but it's still glass, and to ramp up too quickly could create even more stress in the glass. For me, annealing boro is a day long task, but totally worth it. My kiln is 100%firebrick, so when I turn it off at 750 or 700, it still takes about 8 hours to cool to room temp.

There's also a possibility that your batch of DAP is particularly sensitive... my results vary from rod to rod, even in the same batch. Welcome to boro. It's a totally different animal. Hey, if you're desperate for purple, try purple luster. It's way easier to use than the NS APs, especially for a beginner. Truth be told, I don't even bother with AP and DAP since I discovered Purple Luster.

Sarah

[Renee Weaver]

oh Sarah! I'm so glad to hear from someone with the same problem. How did you figure out your schedule? Did you just keep annealing beads at a lower temp, each time lowering it until the black tea look doesn't show? Could you tell me your program for ramping up? Is 1000 your annealing temp? What is your schedule for ramping down? Thanks so much !!!!!

I just had to add that I went to your website. You are the sarah that makes those wonderful colorful tabs that I love. Absolutely wonderful beads!!!

[elle]

Originally Posted by Renee Weaver

oh Sarah! I'm so glad to hear from someone with the same problem. How did you figure out your schedule? Did you just keep annealing beads at a lower temp, each time lowering it until the black tea look doesn't show? Could you tell me your program for ramping up? Is 1000 your annealing temp? What is your schedule for ramping down? Thanks so much !!!!!

I just had to add that I went to your website. You are the sarah that makes those wonderful colorful tabs that I love. Absolutely wonderful beads!!!

Thanks!

I use an infinite switch, so it varies a bit each time. Basically I take 3-4 hours to ramp up to annealing temp, hold it there for 30 minutes and ramp back down to 750 or so over 3 hours, sometimes longer. My pyrometer *reads* 1000 and I know it's actually at or above 1050 inside the kiln because the rubies strike just right, but there is nothing different with most of the other colors. It could be 1075 in there, for all I know. All I know is it works for me. What I'm doing may not even work for you because, like I said, I don't even use AP and everyone gets different results, anyway.

It may be a hassle, but you will probably run several cycles with an adjustment each time before you find the temperature *reading* that gives you the results you want. Pyrometers are not totally accurate, and the hotter the temp, the less accurate the pyrometer is, so keep this in mind. Remember to take notes! With soft glass, it's a range and a few degrees generally won't make much difference, but with boro, even 10 minutes longer or 10 degrees higher can make a big difference. At least, it does for me.
Good luck!
Sarah

[kiko]

Here's a shot in the dark.... Did you use this kiln for pmc firing by any chance? Instead of a temperature problem you may have a contamination problem....Just a thought. Lori

[Renee Weaver]

Hi I did use this kiln for PMC. Probably only about 4-5 times though. How can you tell if you have contamination? Does PMC ruin your kiln?

[pipyr]

I use my kiln for PMC as well...never had a problem with it...should I be worried about that?? hmmmmm

[Cosmo]

If you use your kiln for PMC a lot (like every day for a few months) you can get a silver buildup. If that happens, just open your kiln and turn it on at its maximum temperature and it will burn off the buildup.

As for batch annealing, I do it all the time. At our store, we have customers renting torch time all the time. Most of them are working in soft glass, so I run the kiln at 960 for them. I work boro at the same time, and put it in the kiln right along side theirs. I hold it at 960 just like their soft glass work, and ramp it down at the end of the day. At a later date I put it back into the kiln and ramp it up to 1050 and anneal it again (or I guess probably for the first time, since it doesn't really anneal at 960). No problems to date.

[ukiacat]

I am in here reading about Boro because I just got one of Mr. Smiley's 5lb box of boro shorts. Basically, I know nothing about boro but I do have a suggestion for you about your kiln temp. I have a Paragon kiln which I use when I am melting wax out of a flask as I prepare to cast a piece of jewelry.

Since I NEVER want to overheat a flask and end up with a porous casting, I always double check my infinite switch. Every time I use the kiln for burning out a flask, I use temperature cones which I bought from a ceramics company. They are about an inch tall and they are made so that they start bending over when they reach a certain temperature. The cones are available in different temperature ranges. The ones I use are made to start bending at 1200F. I don't know if you can get them at the exact temperatures you want to measure but anything fairly close would be helpful if you want to get some idea of what your kiln is doing. You would need to run the kiln with a cone sitting on a piece of kiln shelf [do this so that if you don't stop it from melting into a puddle it can be removed without sticking to your kiln floor] and then check it as the kiln temperature rises.

When you see that the cone is beginning to bend, check it more often. When it has really bent over [but not puddled!], make note of what your pyrometer is reading. You'll need to do this a few times because you may actually need to back off the setting more in order to find the setting that bends the cone but does NOT GO PAST IT. You're looking for the setting where the pyrometer holds the temp where you want it. Does this make sense? I'm finding it hard to explain but really it's simple. A ceramics supply company could tell you what the cone temperatures are and they'll probably explain the process better than I seem to be able to do right now. Oh, I'm editing this to say that I don't think you'd need to use a cone for every annealing....in your case you could use it to find the setting you need and just double check it if you think you're starting to have trouble again or you need to figure out another temp setting....

Hope this helps.
J

[Renee Weaver]

Thanks Jennifer, I am willing to try everything and anything! There is a ceramic store nearby, I will go talk to them tomorrow. Thanks for the help!