'Vermiculite' Vs. 'Fiber Blanket'.

Q: I was wondering if you can tell a big difference in using 'Vermiculite' vs. a 'Fiber Blanket' to cool beads. I just got a 'Fiber Blanket', and am about to try it. I've had a few beads break in fragile places, using Vermiculite (example: the lip on the hat on a snow man), and I'm wondering if this will make a difference. I'd just like to hear other opinions.

A: If you are making lampworked beads to sell, I strongly suggest you invest in a kiln. I have purchased many, many lampworked beads from many, many beadmakers and I can say this - I think ALL beads should be kiln-annealed (after being flame-annealed), regardless of how big or small they are. Just my 2 cents. All you lampworkers out there who are only using a fiber blanket to anneal your beads - I think you owe it to the buying public to tell us so - up front. I do anneal ALL my beads, however, I let them cool in 'Vermiculite', remove them from the mandrel, clean them, and then anneal them. I know I'm a lowly beginner at this, but in the class I took, we were taught that we could do it this way, or to put the beads, still on the mandrels in an annealing oven. My question was regarding cooling beads down before annealing. As I understand it, 'Verumiculite', nor a 'Fiber Blanket' will anneal the beads, they just allow for a gradual cool down so the beads won't break prior to annealing. In various industries, large castings of various materials are wrapped with blanket to slow the cooling rate, which makes the pieces stronger, and I have some familiarity with this procedure. The advantages I can think of for blanket wrap over surrounding in 'Vemiculite' would have to do with ease of wrapping over, making sure you had the beads well surrounded by the 'Vermiculite'. The other advantage of ceramic fiber would have to do with temperature ratings, but I think you may be down to about 1400 deg F by that time, and 'Vermiculite' would handle enough temperature for this application. At this temperature I believe the heat transfer rate would be close for both products. The other advantage of ceramic fiber would be that it can withstand higher temperatures than 'Vermiculite' (some blankets are 1800 deg F, others go as high as 3000 deg F). This is because of a high Alumina content, which translates into dollars. If you find you like blanket wrapping, it may be worthwhile for you to look into a welding pad, much like a quilted potholder, except made with high temp fabric, ceramic or high temp fiberglass blanket, and 'Kevlar' thread. Initial cost would be higher, but it would not shed, and would last a very long time.