Just fired up my Prometheus Pro 7 for the first time! Batch Annealing Query

[Fruddy]

.....and touch wood everything seems to be going okay.

Took me ages to get into the damn shed by the way, with these rotten crutches

Okay, so I'm running it empty, as advised.  I have programmed it (I hope!) to reach 530 degrees c in 3 hours, hold for an hour and them ramp down.

I was hoping to be able to batch anneal some of the beads that I have made since I started at home (I have hundreds of the damn things now!) after this initialy empty programme has run without mistake.  But I have just spoken to my friend who is a lampworker and she has told me that I MUST keep all beads off the floor of the kiln when batch annealing from cold.

When I got my kiln, I had a little shelf included, which she says is fine when garaging during a torching session, I can move the beads over as I go, but if I am batch annealing from cold, they absolutely need to be off the floor/shelf.  I don't have a kiln rack and I don't have any mandrels the size that would go into the kiln to make kebabs, or a holder to rest them on.

Is this right? If so, will I absolutely need to batch anneal as kebabs in the future?  I do have beads to practice on (BIIIIIG fugly jar) but I don't want to damage my kiln or the shelf by doing something wrong.

Thanks  very much!

Gimpy!
x

[julieHB]

The only reason, as far as I can understand, to keep the beads off the floor is that if the kiln run a bit too hot the glass might stick to the kiln floor. You can place them on some fibre paper or on a fibre blanket if you worry about this.

I have always batch annealed directly on the kiln shelf with no problems. Some people like to gather all their beads in a ceramic flower pot or similar so they don't roll over the place, and some people place them in vermiculite ( or on kebabs as you say).

I would like to point out that  530 deg C might be a bit hot for annealing: i) some glasses might stick at that temperature, and ii) reduced silver glass might lose their shine. I used to anneal at 520 deg C, but after reading about the risk of losing the reduction I now anneal at 510 deg C. Some people anneal as low as 470 deg C.

HTH.

[hollergrafik]

I have also hear people using a pyrex dish to anneal in, I agree with Julie, 530 seems too high, I anneal at 495 as my kiln runs a little hot.

[Fruddy]

The only reason, as far as I can understand, to keep the beads off the floor is that if the kiln run a bit too hot the glass might stick to the kiln floor. You can place them on some fibre paper or on a fibre blanket if you worry about this.

I have always batch annealed directly on the kiln shelf with no problems. Some people like to gather all their beads in a ceramic flower pot or similar so they don't roll over the place, and some people place them in vermiculite ( or on kebabs as you say).

I would like to point out that  530 deg C might be a bit hot for annealing: i) some glasses might stick at that temperature, and ii) reduced silver glass might lose their shine. I used to anneal at 520 deg C, but after reading about the risk of losing the reduction I now anneal at 510 deg C. Some people anneal as low as 470 deg C.

HTH.

ah, julie brilliant - thanks for that!

What I might try then, is a bunch of beads that I am not all that bothered about... I have sheet of fibre blanket from martin, should I just cut a piece to size and put it into the kiln? Do I need to make absolutely sure that they are not touching then?

If I were to put my maximum temperature up to say then 510 deg c, how long should I hold that for, before I ramp down? Also, could you advise at the rate that I should ramp down, i.e. degrees per hour?

Thankyou, your help very much appreciated!  The instruction manual from Prometheus is a bit sketchy at best!!

Cheers!

[fionaess]

I use a pyrex bowl when I  batch my soft glass beads

[julieHB]

Ah, yes, a pyrex bowl is perfect!

I anneal for an hour. I have always just placed them in a heap in the kiln, and have not had any problems with beads sticking to each other. If my memory serves me right I think Rubino oro is one of the glasses that can "stick", but I don't think it is a problem at 510 deg C. Just make sure you ramp up a little slow towards the end, so your kiln doesn't overshoot too much.

I think a cooling down rate of 50 deg C per hour down to 378 deg C is fairly standard (and quite conservative - better safe than sorry  ).

[Fruddy]

Ah, yes, a pyrex bowl is perfect!

I anneal for an hour. I have always just placed them in a heap in the kiln, and have not had any problems with beads sticking to each other. If my memory serves me right I think Rubino oro is one of the glasses that can "stick", but I don't think it is a problem at 510 deg C. Just make sure you ramp up a little slow towards the end, so your kiln doesn't overshoot too much.

I think a cooling down rate of 50 deg C per hour down to 378 deg C is fairly standard (and quite conservative - better safe than sorry  ).

*adds Pyrex bowl to shopping list* - do you just put them in, in a heap then??

So, Julie, ramp up tp 510 degrees, say in 3 hours, then anneal for an hour at this temp, and then rampdown at 50 degrees per hour until 378 and then, do I just switch kiln off and leave it to cool?

[dangerousbead]

I put the shelf on the kiln floor, just in case, and anneal for an hour at 510c. Or if there are a lot I put a bit of thin fire paper on the floor for one layer of beads and the shelf on it's little feet things to make an upper level. Beads that touch have never stuck yet. Good luck with the kiln, I'm sure it will all be fine.

[fionaess]

Yes, I pile as many in as I can - until they are almost overflowing... bead sets and focals, oh, and don't clean them before you anneal them

[Margram]

Put a couple of clear ones in so you can do the polarising filter test on them to see if they are annealing properly .

[Blue Box Studio]

pyrex bowl = charity shop - mine always seem to have them.  I use a pyrex bowl or the lid, depending which is to hand.  I get a lot in my SC2 that way.

I use the SC2 batch annealling schedule I found on the forum and that goes to 520.  Not had a disaster  - yet!  I've just got the confidence to fire mine over night, I was twitchy at first.