B**gger! I just opened my kiln to get out what I thought would be a kaleidoscope of plain opaque beads, only to find that most of them have soot lines in >:(
I'm using a HH on bulk, and have recently taken a foray into frit, so maybe I wouldn't have noticed if it's been happening for a while. I think the propane tank is nearing the end (not much of a slosh when I swirl it), would this make a difference? The end of my HH doesn't look particularly dirty, but could it need a clean? Or is it just the dirty nature of a HH flame? But then I have made plenty of clean plain opaque beads before :'(
I'm particularly miffed, as I was doing it as an exercise in uniformity - they're all perfectly formed and equally sized, just covered in thin black lines! Yuck
Are the sooty marks just on the surface ?? Or deeper within the bead ?? It sounds to me like it could be dirty fuel....especially as it is in all the beads. It can get a bit like that at the bottom of the cylinder.. mine almost needs changing again and you can hear the crud scraping round the botom with the fuel when i swill it around.
If it was dirt on the glass, I'd be inclined to think that it wouldn't have affected every bead. You can always give the rods a wipe with a propriatory glass cleaner beforehand to eliminate dirt though.
HTH
Les xx
The trouble with clear glass on a HH is that it takes an age to melt - so the temptation is to turn it up. Whenever i did that, i found it got sooty. Turn it down a bit - and be sure to take the scummy bit off the end of the rod - should be OK!