Annealing question

AndyPan · #1 2009-07-20, 7:28am

Howdy! I am brand new to this awesome craft, having just started last Monday. Have been having a blast trying out a ton of different techniques, and while I am hardly proficient at any of them yet, I have seen a marked improvement in what I am able to do in such a short time.

Over the course of last week, I made about 25 or so beads. I put them all into a crock pot filled with Perlite (wasn't able to find vermiculite around here, but the Perlite seems to do the trick), as I didn't want to kiln anneal for the 4-5 hours at night the kiln would need to run (home by 7, work till 10). I did a batch annealing on Saturday, and that went pretty well. I did have one small issue though.

Maybe 6-7 of the larger beads all came out of the kiln with a small rough spot on one side. I know what it's from, the brick on the bottom of the kiln. I have a Paragon Bluebird XL, with bead doors. The beads were put into the kiln still on their mandrels, with the doors closed and sort of pressing on the mandrels. So I am pretty sure that the pressure on the madrels pushed the beads into the brick, and coupled with the heat, was enough to impress the bead into the brick a bit.

Two questions. One, would it be better to remove the beads from the mandrels before a batch anneal? And two, if better to leave on mandrel, what do I need to do to keep this from happening again? Thanks in advance!

Moth · #2 2009-07-20, 7:38am

Annealing temp is not hot enough to soften the beads.

Your kiln is either running hotter than you think, or it is spiking above temp often enough/long enough to soften the glass and allow it to be pressed into the brick.

I suggest turning your kiln down about 20-40 degrees (depends on how high it is spiking).

Also, get yourself one or two of those little $6 rod rests or a mandrel rack and put it in your kiln to keep the beads from touching the floor of the kiln.

It won't hurt them to touch the floor- temperature is the problem- but it is still nice to have them up.

Also, it doesn't really matter whether they are on or off the mandrels but I took them off. I didn't clean them though because I waited until after they were annealed. If any of them cracked while annealing I didn't have to clean them. LOL I hate cleaning beads.

Good luck.
~~Mary

Three Muses Glass · #3 2009-07-20, 7:42am

You just need to pick up some rod rests. They're bent stainless steel with little cut-outs in the bend, about 6 inches long. Most glass suppliers will sell them. That will keep your beads on mandrels propped up so they don't touch the brick. Or if you have any kiln furniture hanging about, you can use that too. Someone used to make custom kiln racks but I don't think they are anymore. There are a few threads about kiln racks and such around here, some have pics of peoples solutions.

AndyPan · #4 2009-07-20, 7:58am

Okay, that's pretty much what I thought. Was my first annealing attempt, so I may have had the temps on the annealing schedule a little off. Although, because the mandrels were sticking out the door, the door was slightly ajar, so it may have been heating hotter to compensate. <shrug> Live and learn, I guess.

I do have a rod rest on order from Arrow Springs; unfortunately, they were out of stock on that at the time, so will have to wait a bit. Weird thing is the small distortion was only on a few beads, not all of them, though they were all in there in the same way. Also, weirdly enough, the general shapes of the beads were relatively unaffected. I'll see what I can find to help with the next annealing. Thanks for the help!

Moth · #5 2009-07-20, 12:50pm

Well, ya know how it is. Some glasses get soft easier than others...but none of them should be softening up at annealing temp.

I always have mandrel ends hangin' out of my kiln.

The rod rest will serve you well though. I have one in my kiln too. I like to keep the beads from touching each other or anything else until the temperature stabilizes (I garage my beads as I make them now). If they are hotter than the kiln, I don't want them to thermal shock something else, or get shocked by something else in there. After they've been in there a while, I jockey them around and don't mind so much if they touch because they are all the same temp.

You won't have that worry with batching though- because they are all going in at one time.

Sounds like if your kiln was spiking high- it wasn't by much or for very long. Just long enough to make 'em tacky and let them pick up crap off the kiln floor. The rod rest would have prevented that. I like annealing good and hot- the high end of the annealing range.

But really annealing temp should not make your beads tacky. Unless maybe you have the surface coated with enamels- enamels can get tacky at high annealing temps.

Good luck.
~~Mary

Bea · #6 2009-08-05, 12:57am

Hmmmm - this worries me somewhat, I have just ordered a BlueBird XL kiln......... I thought that Paragon Kilns were made to last and considered good!

PerfectDeb · #7 2009-08-05, 1:15am

i have the same kiln and i dont have that problem - just lower the temp a little, i found the recommended temp that came with the kiln was too high anyway

Elizabeth Beads · #8 2009-08-05, 6:01am

I take my beads off the mandrels and pile them in a ceramic dish to batch anneal. I clean them first with a dremel and I am not gentle with them. If there are any weaknesses I want them outed. I have very low breakage, maybe because I am not making very large beads.

Moth · #9 2009-08-05, 6:38am

Quote:

Originally Posted by Bea

Hmmmm - this worries me somewhat, I have just ordered a BlueBird XL kiln......... I thought that Paragon Kilns were made to last and considered good!

They ARE good. I don't consider this a kiln problem...just a temperature settings problem. It is possibly set too high. Kilns all have personalities and you just need to get to know yours.

My kiln runs a little cool...not a huge amount cool...but still. I like to anneal on the high end of the range because of that.

You will get to know your bluebird and it will be fine.

NMLinda · #10 2009-08-05, 8:15am

Rod rests are a great idea in general. You might also want to get some of the Orton cones that fusers use and verify that what you set your kiln's temperature at, and the temperature you see on the guage, is what the kiln is actually operating at. Get one that bends at 950 degrees if you can (convenient number in the moretti annealing range that should be easy to read on the guage) and another at 1000 (approx temp at which moretti starts to soften and flow slowly). I think you can slide these in after your kiln has come up to temperature and stabilized (experienced fusers, please help!). Set the kiln temp to stabilize at 950 degrees (with the door closed) based on the what the guage says. Let it stabilize for 4-5 hours at least, then let the kiln come back to room temperature before you open the door and look at the cones. If the 950 cone folds over, but the 1000 does not, your actually temp is somewhere between 950 and 1000 (you can even put in a third cone with a value between the two if you want). If both fold over, your real temp is above 1000, which means that your beads have probably softened and started to flow a bit. The rod rest will definitely help, but it's important to find out if you have any major differences between the real temp of your kiln and what the temp reading says. Sometimes the guages aren't calibrated correctly for the thermocouple. sometimes, as Mary notes, as the kiln cycles, you can get big temperature spikes. If your kiln cycles frequently (which it will with the door open), the average temperature it reaches can be higher than you might be aware.

Hope that helps
Linda

Bea · #11 2009-09-04, 7:59pm

Quick update - have received my BlueBird and I LOVE it! Just being able to take beads out the morning after and know they are annealed and clean is a great feeling after batch annealing all these years.
Am still trying to work out the best garaging temp as I find the radiant heat from opening the kiln door to put the beads in is a challenge for me - I have tried both 400C & 450C.
400C felt better on my hand and beads survived (but they were tiny ones) but am worried as I make larger beads that it might be too low.
Annealing is @ 520C.

cheers

pam · #12 2009-09-05, 6:36am

Just a suggestion, what I do is leave my door open while I am garaging, then when I start the annealing cycle I close it. This keeps the ups and downs you get from opening the door, closing it, opening it again. Of course it depends on the kiln. I wouldn't leave a top or front opening kiln open, but a bead door is fine.

Bea · #13 2009-09-05, 9:27pm

Pam - thanks for the suggestion but I don't think it will work for my new kiln. It is the Paragon BlueBird with double 'swing doors'.
I set the graraging temp @ 450C last night and use my 'duck billed' hemostats to help me move the mandrels in a bit further once I popped it in the kiln.

I am interested to know what other BluBird kiln owners are doing though.....

cheers

Doolollies · #14 2009-09-05, 9:47pm

For new brick kiln owners... it's a VERY good idea to get some kiln wash and wash the brick in case of malfunction/meltdown. Molten glass will ruin the brick. Ask me how I know this.

Bea · #15 2009-09-05, 9:57pm

Linda
LOL - I think I can guess....... but not to worry, I have lined the floor of the kiln with fibre blanket.

I fuse and do PMC as well so I am aware of some of the 'kiln actions' and am trying to be extra careful with my lovely new toy.

;0

Doolollies · #16 2009-09-05, 10:52pm

Yes. I have to admit my boo boo melt down was fusing. I haven't done the melt down with my beads (yet) but in the end the kiln wash would have been cheaper as well as easier than cleaning up the mess and repairing the brick. But live and learn. Glad to hear you you have it covered. LOL. Have fun.

likes to make glass stuff · #17 2009-09-06, 8:43am

get a kevlar glove for putting mandrels in. I was amazed at how this little thin thing actually made a huge difference with the heat on my hand.

they're just these little yellow gloves, and they've made putting stuff in my front loader so much simpler.

Moth · #18 2009-09-06, 9:24pm

I have kevlar fingerless gloves with sleeves and I adore them for working close proximity to high heat.

krisdaka · #19 2009-09-07, 5:04am

I bought a "Ove Glove" because it was there when I was shopping, and I put a piece of rubber on the handle of my Jen Ken. It's made of metal and I couldn't touch it with my bare hands..I saw the idea at B&B where Arrow Springs had their kilns....