I've made a cabochon with pea green as the base colour. It got red lines around the edges, I assume it's the same as can happen with turquoise? Is there anything that can be done about it now?
Could I have done something about it at the torch? I saw the stripes show up and tried to turn the propane up and down, heating more, letting it cool etc but nothing seemed to help and I was afraid I'd only make it worse by doing the wrong thing as I've forgot what exactly causes it.
Hi Noora
The red lines are caused by a reduction flame. Now they are there, you won't shift them I'm afraid.
I'm not sure what torch you are on... on a hothead this can be hard to avoid as the flame is naturally reducing. Try working further out.
On duel fuel, it's a sign your flame isn't neutral, so you may need to turn down the propane or turn up the oxy until you get to neutral
Thanks! I probably did have a slightly reducing flame, I had the propane turned up just a little (I'm on a Minor) hoping to get a warmer flame as it takes ages to melt and shape the larger cabs. I didn't think it would make much difference from a reduction point of view since I usually have to turn up the propane much more when I actually want to reduce some glass.
Next time I'll just have to be more patient then :-\ I'll have to get more of the thin cab mandrels from Off-Mandrel, the thick ones from Tuffnell take ages just to heat up the mandrel and I'm getting impatient before I even start shaping the glass ::)