Does anyone use this method.
I'm finding that some of my beads crack ??? even though I leave them in the vermiculite for hours. I'm thinking about buying a cheap slow cooker that has a keep warm function and then when I've finished beading turning it off to slow the cooling down. Can anyone advise me on this please?
I don't have enough time to do an awful lot of beads in one go, or I'd anneal as I went.
Heeellllllppppp!
Thanks ;D
I just use my vermiculite in a casserole dish, don't worry about heating it up, and I rarely get cracked beads. I do make sure that I remove them from the flame very slowly, though. I do watch the thickness of the bead too.
It depends on how big your beads are but I have great success with a £7 slow cooker from Asda which I've taken the ceramic dish out of and put the V directly into the metal area. I rarely have broken beads except small flat ones occasionally and very big flat ones though I get more whole ones than broken ones. Good luck, I leave mine on full heat the whole time I'm working and then switch it off at the end but I don't take the beads out till they are completely cold.
Its horrible when you've made a super bead and then it breaks isn't it.
Yes it is frustrating.Mostly been having trouble with lentils. Bought a press from Martin at the Hatfield Bead Fair, and made some beads I'm really chuffed with only to find one has cracked. Also had one crack a day or so after I made it. Not fully crack, but a hairline crack down the middle. ??? Not sure why this would happen either?
Thanks for the help! ;D
I nearly always work with vermiculite and a slow cooker on low. The key is flame annealing the bead properly before putting into the vermic. Gradually work your way up the flame and bathe slowly in the top part bring out, count to 5 quickly and bury deep in vermic.
Kaz
I have a slowcooker too. It seems to work a treat. I hardly ever get cracked beads. But bigger ones seem to be the most likely to go if any do. by bigger I mean 30mm or so in size, The ones I have spent more time on and am most pleased with normaly. I guess the extra working has built up more internal stresses in the glass.
I don't use a slow cooker with mine and I rarely get cracked beads - when I do, it's usually the big flat ones. I'm just very careful about flame annealing before I pop the bead in the vermiculite.
Don't use it so much now as I tend to use the "anneal as you go" method, but I lost very few beads to cracking when I used the vermiculite in the slo cooker method. (didn't help the fuglies though :P) Check the second hand shops, you might pick one up for a couple of quid if you're lucky :)
I don't even try to make lentils unless I can put them straight into the kiln
Hi,
when using vermiculite, I use a slow cooker bought from asda for £6 last summer and just leave it on low and switch off and leave beads until next morning. I do however flame anneal every bead, I make as standard. If I try to hurry and take beads out earlier than that I get breakages,
Hope that helps. ;D
Dianne ;)
I've lost a few doozies of a bead but i now have an electric fondue set for my vermiculite....cheese is too fattening so i am saving my bum from expansion LOL.
Why do peolple buy fondue sets anyway??????
QuoteI use a slow cooker bought from asda for £6 last summer and just leave it on low and switch off and leave beads until next morning. I do however flame anneal every bead, I make as standard. If I try to hurry and take beads out earlier than that I get breakages,
This is the same for me. I was so proud of one bead I made out of an encased twisty, got all excited took it out too early to show DH. Five mins later I heard to tell tale crack as it sat proudly by my side. :'( I still have it, couldn't bear to throw it away. ::)
I have had more success with slow cooker and then I batch anneal when I have enough to fill the kiln. ;D
Thanks girlies! :D Off to ASDA tomorrow. ;D Think I'll give it a try, I really don't have enough to anneal as I go, so will try slower flame annealing and putting in slow cooker and see how it goes.
;D
I third the flame annealing. I use a HH, and after cooling the bead in the end of the flame, I use my oven glove and wrap it around the holes to get a propane-heavy flame. I keep the bead in there until the glow has really gone, then shove it in the verminculite
That's in a round terracotta pot lined with ali foil.
It's probably not as error-free as a kiln, but I've not had any breakages since my first batch.
Can I chip in with a wee comment? Make sure your mandrel doesn't touch the pot if it's metal, either the point or the long end of the mandrel. The metal will conduct the heat away from the bead more quickly and shock it. Not obvious, but it does make a difference.
I fourth the flame annealling approach too. Not sure that a slow cooker actually helps that much for the vermiculite but also can't do any harm. Be careful though - the vermiculite can get very dusty when it's hot so dont' stir it all around very much. Make sure you have enough vermiculite around each bead - you'll need about 2inches all round to provide enough insulation to allow the bead to cool.
I too always had trouble with lentils when batch annealling. There are two things going on here:
Firstly - you've used a press to shape the bead and a press will always super-chill the outside of a bead which will really stress things up. You should bathe the bead in heat for quite a while after shaping to try and get the outside up to the temperature of the inside of the bead. This means you need to place the bead high up in the flame because you don't want to lose the shape you've just laboured hard to achieve by heating the bead too much.
That lentil shape makes for quite a flat middle of the bead so it will lose heat from the centre much quicker than a round bead will - this will also lead to a higher stress scenario.
Flame annealing aims to reduce the stress in a bead to a tolerable point before plunging it into the vermiculite. Although it's not a substitute for kiln annealing it will help to make your beads less stressy in the run up to your batch annealling. Here's how it works....
If you're on a dual gas torch, turn off the oxygen until you have a billowly yellow flame. If you're on a hothead take the bead up to the top of the flame and you can even cover up the air holes.
You are trying to bathe the bead in a soft flame which is around 500 deg c. Propane alone will provide this temperature. The idea is that you hold the bead in this flame for as long as possible so that the outside and the inside of the bead even out at around 500 deg (ish....). This is around the correct annealing temp for Effetre. You ideally want to hold the bead here for about an hour, but that's not a practical option so try to go for aound 1-2 mins in this yellow flame. In this time your bead will get coated in black soot, which will act like a little insulating jacket when you plunge into the vermiculite, so the soot is a good thing. You can just wipe it off so don't be concerned about it. After you have flame annealed for as long as reasonably possible IMMEDIATELY plunge your bead into the vermiculite. This SHOULD minimise the crackage of the lentils, unless of course they were cracked before they went into the Vermic. The flame annealing is good though as it gets the bead down to a reasonable temp (i.e. one where you won't get bits of vermic sticking to the bead) so you don't have to waver around in mid air wondering whether you are hot enough to prevent cracking but cool enough to prevent vermic bits sticking to the bead.
Hopefully this should minimise your lentil cracking.
Great advice Sal :)
I also have a piece of fiber blanket that sits on top of my pot of vermiculite. It helps to keep the vermic. that little bit warmer too :)