Hi everyone, I hope that someone will be able to help me out with this. I think my bead cube might be overshooting it's set temperature. I've only been lampworking a few months and when I got my kiln I started out using the garage programme already set on it, but I recently noticed that I'm getting little imperfections on the surface of my beads which look like they have slightly stuck together or a mandrel has left a mark. I thought that maybe I was putting them in too hot, so started making absolutely sure that all the glow was gone from them and waiting as long as I dare before I put them in the kiln. I do tend to stack them up but always put the one I've just done in so that it's not touching anything and then when the next one goes in I move the previous one across to the stack (if that makes sense!), but I was still getting the little glitches. So I've set a new programme for 516c rather than the 520c but it still seems to be happening. I've also noticed a couple of times that the temperature is shooting up after I put a new bead in, on one occasion nearly 540c. Is there a reason it's doing this? Am I doing something wrong? I would really appreciate some advice as I'm rather new to this and it's so frustrating making beads I'm happy with and then realising that they have a little nick on them.
Thanks
Tamsyn
When you put the bead into the kiln, even though the glow has disappeared you'll still be putting the bead in at a much higher temperature than the kiln is set at. Maybe 700 - 800 degrees.
If the bead touches anything at this point it will mark the surface of the bead - consequently you have to ensure that the bead is "floating in air" for sufficient time for the bead to get down to the kiln temperature. I don't start to stack my beads until I'm really sure that they are nearer 520. I usually give them about half an hour to make sure, though I appreciate that this is difficult in a small aperture kiln like the bead cube.
The Kilncare controller does "overshoot" a little as it tries to regain temperature - especially if you have had the door open for a while. But even overshooting to 540 won't make your beads slump. And in fact the controller isn't actually displaying what it probably going on in the kiln - it's a sort of "feedback oscillation" thing. That's not a very technical explanation - but basically don't worry about the controller.
You may need to build a "grid" type thingy to fit into the back of the kiln into which you can poke the end of the mandrel in order to get the bead to "float". The nicks are almost certainly coming from the floor of the kiln.
Hi, are you using your star shaped bead rest to sit the bead mandrel on until it cools to kiln temperature as Sal says?
Lee, sorry to jump in on this thread... but I had a beadcube from you a few months ago and didnt get the star shaped thingy (I know what you mean as I've seen on in someone elses!). I got a little rectangular brick thing and a tile. Am I missing out? ;D
You sure are :( ???, PM me your address and one will be with you later in the week ;)
Perhaps Lee could post a piccy of the little 3 pointed thingy in action - so that then we can all see exactly what we should be doing with it!! ;D
Hi Tamsin, I have a bead cube and although I don't the garage setting I do use the batch annealing setting without any problems. I pop my beads into annealing bubbles (bought from Manda at Mango Beads) when they come out of the torch and leave them covered for a good few hours before I remove them. All my beads are cold when I put them in, I stack them 'kebab' style! Never had a problem.....good luck!
Jenniex
Thanks for the replies. I have been letting them 'float' individually when I first put them in, using the little three pronged thing and the long brick thingy at the back of the kiln so they are not touching anything. I've been doing some really detailed stuff so it's usually at least half an hour between beads being put in. I guess that it is just that they are still a little to hot when I stack them, I'll have to try to keep them apart longer. Thanks Sal for putting my mind at rest about the controller.
Thanks
Tamsyn x
I'll stick something on later gang...piccy wise that is
Mine looks like this - (http://www.kilndr.com/images/ACS4.jpg) Only a touch bigger...
I expect you position it inside so you can rest your mandrels on it... i wouldn't know as I don't put beads in my beadcube.... ???
Here is one of the Star Rest purposes beautifully demonstrated by a welding rod and and element connection gland ;D Sorry Claire, the lads have lost your beady samples that you kindly donated.
As you can see, the 20mm diameter gland is in free air until it stops being tacky (if it was a hot bead of course).
The Star Rest can also be used to sit the shelf on to raise it off the floor.
(http://i181.photobucket.com/albums/x168/shiffa_2007/star-rest.gif)
so what's the rectangular brick for? cos I've been using it to rest the end of my mandrels on.
That's fine too mate.
thats what i do too......rest mandrels on rectangle and in slot then move over when i put next one in .......i have had the odd one stick but thats my fault for putting in to hot, not having enough hands and trying to '' get just one more in '' ;)
Thanks Lee - great piccy! I would have been trying to stand it on one of its points and rest the mandrel in the V - a bit like a catapault!
Me too!