hi guys. having real problems with my larger beads cracking. i havent got a kiln yet but seriously considering it now more than ever.
i am making fancy flattened beads that are generally oval shaped, around 40-55mm long and 6 mm or 8mm thick. i reheat the bead after flattening and flame anneal the bead slowly at the end of the flame before putting straight under fibre blanket. Most of the beads are cracking whilst trying to remove from the mandrel. I am gently warming the bead in warm water to help removal but then comes the dreaded break.
some of the batch i lost today were the best i have yet made and i was gonna post them for you guys to see. its seriously distressing to see the little fellas crack in such a way.
is it completely essential with making these type of beads that i use a kiln?
Which kiln would you recommend?
Do you place the bead whilst on the mandrel straight in the kiln?
My wife has managed to get me some orders for these beads from friends and colleagues and i am now running out of time and glass to make the beads now. cheers.
Ooo err, those are big beads to be putting in a blanket...a kiln is preferable - or people have been enthusing over Manda's (Mango beads) annealing bubbles, might be worth a try. In the meantime, could you make smaller versions of the beads plus a couple of nice spacers for your orders?
simple answer. yes beads that big need annealing. especially when they are flattened as the thickness is uneven then.
there are a couple of other options before getting a kiln, but if you're selling beads they ideally need to be at least batch annealed, especially if they are that big.
you might try annealing bubbles (Manda at Mango beads sells these, think tuffnell does them now too)
I am told they are better than vermiculite. but I don't know how either compare to a fibre blanket, I would have thought that all that opening and closing of a fibre blanket would let heat out, where as with the others you try not to disturb the beads you've already made when you put them in.
you might also try putting your annealing bubbles/vermiculite in a slow cooker, warming it up before you start, putting beads in, then switch off some time after you finish, this means they will stay at a more constant temperature for longer, and the whole thing cools down, rather than just the beads in it.
you could have someone else batch anneal them for you (usually this involves taking the mandrels out first, so may not be any good)
"Do you place the bead whilst on the mandrel straight in the kiln?" yes, if you had a kiln with a bead door.(if you don't have a bead door or collar then the mandrels wont fit in, unless its a big kiln, which will cost you more!)
some kilns to look at, there may be others, but these are the ones that are the easiest to get hold of here.
Kiln care bead cube
Paragon SC2
prometheus
there will be threads mentioning these on the forum here, reviews and other info.
and for some general annealing info, see the wiki here http://www.frit-happens.co.uk/wiki/Annealing
Could be worth trying the bubble. But the bigger the bead the more chance of cracking with batch annealling and once you start pressing the beads that causes more stress that also ups the chance of cracking problems.
Try not to let them get cold while workng and make sure you give them a good warm after pressing especially at the ends, obviously being careful not to over heat. When I do my big zoozii lentils press tree beads I make sure I keep warming the back of the bead in between each addition of stringer on the tree. Then when I've finished I warm both sides, especially near the holes where the bead is thinest, but in a slightly bushier flame than I would normally work and out further in the flame. I do put them straight in a kiln which is the safest way but even so you need that heat there in the bead.
Which kiln depends on your budget and how much beadmaking you are doing. I started with and SC2 and now have a Maxi from Kilncare. I love the Maxi, I think the quality is superior to the Paragons as is the after care so if you want something smaller/cheaper then maybe a beadcube from Kilncare. I haven't used one myself but lots of people here are fans and will no doubt be along to sing its praises.
One way or another, you do need to anneal your beads if you are sellng them. If you can't afford a kiln then ask someone to batch anneal for you.
I've been making some 'longer' beads recently - hearts and tubes/cylinders to just over 30mm long. Had some cracking problems with cracking at the ends while I was working (Reichenbach antique in particular), but managed to melt enough again to get rid of the cracks. Thought that maybe the problem was that the weather was so cold and I couldn't get the whole bead in the flame as the same time (hot head).
But that said I am getting more thermal cracks than usual with antique clear than other glasses even on smaller beads......hmmmm!
However, the hearts at around 30mm are fine. I use vermiculite in a slow cooker. I set it to the higher setting and let it warm up then leave it on for a couple of hours after my session is over. In the very cold weather I have bought it indoors to cool slowly rather than leaving it in the shed where it probably would cool very quickly. Then I batch anneal. You do need to let the glow go off the bead before putting it into the vermiculite, otherwise you risk distorting the bead. A balancing act between cold enough and not too cold.
I had this problem with cracking, tried the bubbles and they didn't make much difference, bit the bullet and bought a bead cube. Haven't lost a bead since!
I changed to annealling bubbles and have not lost very many beads in fact I think I have only lost two. I lost about 80% with a fibre blanket. The bead cube is a great kiln lots of people on here have one your would love it. ;D
I started with using fibre blanket and didn't loose too many - but the bigger beads def were more prone to cracks - esp vertical ones along the mandrel. I have switched to using annealing bubbles and as a general rule I get much better results with the big beads. I have a paragon SC2 kiln but I only turn it on once a week and do a batch anneal. The best thing to do if making big beads as you are is to anneal them as you go along to minimise breakage. The bead cube is a great starter kiln but a bit restricted in size if you start producing more and more in each session.
thanks for your responses, i really appreciate it. Sounds like i have to bite the bullet and get a kiln. I have looked at the bead cube and its only the size of it that is putting me off. i am also looking at the promepheus pro 7 and the sc2. its either that or buying a slow cooker and fill it with vermiculite (heating it up before session). These larger beads are in demand at the moment but its not going to work for me if they keep breaking.
I have an sc2 with the bead door, I turn it on every session, I haven't ever batch annealed. It's about the same size as a microwave, only a bit taller. This was of interest to me at the beginning because I worked in my kitchen for a year :) I think it is fine, but I haven't tried the Kilncare kilns yet but am following peoples reviews with interest.
I was using vermiculite in a slow cooker and making sure it was well heated before putting anything in but was losing a lot of beads and it was always the bigger ones. They used to crack along the mandrel, sometimes up to a day after I'd removed the mandrel.
Two weeks ago I bought an SC2, have made over 50 beads since and haven't lost one!!
Mine has the bead door so is easy to load (and I can look at how lovely they are every so often too!).
I would most definitely recommend one.
I have an sc2 with a bead door and my mum (jayspangles) has a bead cube. The SC2 is a considerably larger unit than the bead cube. I think mum can get about 30 or so mandrels tucked in there tightly without compromising the door closing too badly. I can fit prob 50 or so in in addition normally to 4 or 5 bead kebabs - I had the best part of 250 beads in my kiln at the weekend in one session - both on mandrels and kebabs. Also with the SC2 you can fuse and slump small items and also do silverclay etc if you feel that you want to explore other crafty avenues. It is personal preference in the end but I think that a lot of people think they should start small but 6 months later regret it and feel they want to upgrade to a bigger capacity kiln.
If buying a kiln isn't yet an option, try not pressing the beads too thin - try and make sure that each side of the mandrel the bead is at least the thicness of the mandrel again - so if you have a 2mm mandrel the bead needs to be at least 6mm thick. When you've made your beads give it a good warm slightly higher up in the flame - this allows the bead to have some heat without melting it.
hope that helps
i use the annealing bubbles in a slow cooker and have no problems making large pressed hearts and lentils and even goddess beads without them cracking, actually i think in the entire time i've had them (almost a year now) i've had only 5 or 6 beads crack, the key is to make sure your not pressing them too thin over the mandrel and are giving them a good flame bath before you tuck them away!
Quote from: dunkster on December 06, 2010, 11:08:29 PM
thanks for your responses, i really appreciate it. Sounds like i have to bite the bullet and get a kiln. I have looked at the bead cube and its only the size of it that is putting me off. i am also looking at the promepheus pro 7 and the sc2. its either that or buying a slow cooker and fill it with vermiculite (heating it up before session). These larger beads are in demand at the moment but its not going to work for me if they keep breaking.
I bought a Prometheus Pro7 at the beginning of November and I am absolutely thrilled with it. It's a super kiln, easy to use and the inner chamber is slightly larger than an SC2.
Can't recommend it highly enough. ;D
I lose loads of beads to thermal shock >:(
Unfortunately I have to batch anneal, because I run an extension cable through a window from the house to the shedio and so can't leave the kiln running overnight or when I go out.
However, I very rarely lost any beads during the two years I was using the Hothead, I have only started having problems with the Bobcat ??? So I have concluded that my problem is less to do with the cooling down and more to do with how I I work the bead in the flame and then finish it off before putting it to bed. The Hothead flame was bigger and bushier, so I guess it was much easier to keep the whole bead warm. I've now had the Bobcat for a year though, and I still haven't got the hang of looking after my bead in the flame. :(