Glass needs to be annealed, not so much the size of the beads I usually make, but if you are selling to the public, or making bigger beads it becomes a bit of a necessity.
If I made a bead and just left it out on the side it would crack in two as it rapidly cooled. You can cool it slower by a variety of methods, so that small beads do not crack... but this does not anneal the glass, it can still contain internal stresses that may fracture later on.
To anneal beads you need a kiln.
Kilns come in many shapes and sizes, mine is a small table top kiln and because I knew I also wanted to try my hand at glass fusing, I chose a kiln that can be used for both.
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| Test firing - reject beads ready to be annealed |
Annealing strengthens the glass and makes it less prone to breaking, once glass has been annealed it can last for many years. You do this by using a kiln to basically "soak" the glass at the correct high temperature for the glass you're working with and then cool the glass VERY slowly in a controlled manner, so that so that the stresses and strains are removed, for this you need a programmable controller so you can set the speed at which the kiln heats and cools (ramp).
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| Programmer built in to the bottom of the kiln |
Temperature wise when I'm annealing beads my kiln doesn't usually run hotter than 520oC, however when I'm fusing I typically take it up to temperatures of 805oC.
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| Full door with integral bead door |
Due to wanting to fuse I chose a kiln that has a square interior space and more height, and mine has a "full door" as well as a "bead door" which is essentially a smaller slot door within the main door, so I can put beads in as I'm working.
What surprises people is how long this all takes, if I start a programme to anneal my beads, I won't see what I've made until the following day!
Would you be able to wait a day to see what you've made?
I am not as patient as I used to be, so I'd probably have to do something else (like a day trip) so as not to struggle as much with not opening the kiln. It would still be tempting, however. But I've burned my hands enough on our little toaster oven, that I /know/ I don't want to do that with a kiln!
ReplyDeleteLuAnn (approx #369 on the list) @ Back Porchervations.
(and one of co-host AJ Lauer's #wHooligans)
Hi LuAnn
DeleteThe only thing that stops me is knowing I could ruin the work!! But sometimes I wish I could speed the process up...
Mars xx
LOL we're both talking kilns today!
ReplyDeleteAs I talked about for F, sometimes 15-20 minutes feels like a lifetime, so I don't know if I'd be able to wait an entire day :D For silver beads I think the time in a kiln is only a few hours. Good for me, and good for my husband, who would freak out if something was running that hot for an entire day if we weren't at home. Not that I have a kiln yet anyway.
That is neat that they come with a bead door. I had never seen that before. I guess because most of the videos that I've watched have been for silver, not glass.
Tracy (Black Boots, Long Legs)
As I tend to batch anneal (i.e. cool first by another method then do in batches, not straight from the flame) I don't really use the bead door much, it's designed so you can have your mandrels poking out the letterbox... but I take mine off so the bead door can stay closed - but that's only because at the moment I'm not working big enough to need to go straight from flame to kiln. With bigger beads you can't cool down first, they have to go straight in or they will break!!
DeleteMars xx
p.s. I would never leave a kiln running unattended, I don't mean sitting over it the entire time but I'm always around when I work with a kiln. My longest programme is about 9 hours on the fusing side, I don't mind leaving a kiln once it's completely off and cooling and below a certain temp which is generally around 372 or lower.
Deletep.p.s - takes about 24 hours from start to finish sometimes to get cool enough to take stuff out, once programme's run and then naturally cooling down, as the rate of cooling gets slower by the hour if the heat retention is good!
DeleteI'm sorry it's taken me so long to find my way to your blog (for some reason, I thought you were writing about Hungarian animation), but I've caught up with your A to Z series and WOW! Your bead work is beautiful! I actually have a glass bead with a story you might be interested in. A couple of years ago I found some Russian blue trading beads on a beach in British Columbia (a former First Nation village). What makes them so interesting (apart from the age) is that they were all hand carved and used as ballast for ships sailing over to the new world.
ReplyDeleteCheers,
Stephanie
http://www.svcambria.com/2016/04/k-is-for-kayak-and-other-things-that.html
Hi Stephanie
DeleteThat would be Mop Dog :) Thanks, glad you like it.
Beads as ballast and handcarved?? Sounds crazy! I'm imaging huge things, but I'm guessing it's lots of little ones... what a find though!
Mars xx
That sounds complex. It would drive me nuts having to wait a whole day to see how things turned out. It's bad enough baking a cake :)
ReplyDeleteTasha
Tasha's Thinkings | Wittegen Press | FB3X (AC)
It can be really difficult. The worst (both for waiting and the final result) was my attempt at fused beads. Long wait and disaster!
DeleteMars xx