Just because …….. I got a second hand mold from eBay, cleaned it up (with a washing up sponge and wet sandpaper) and kilnwashed it.
Strange mold as it seems too big for a beer bottle and too small for a wine bottle.
I wondered if I’d have to clean the mold each time and re-kiln wash. After checking information at Warm Glass for the kilnwash (using Bullseye kilnwash) this said that firings over 704 degrees Celsius would need to be cleaned off and re kiln washed. (Though other info suggests that molds need only be ‘touched up’ with kilnwash between firings – guess another thing to test). So I thought I would try a cooler schedule first to see if I could get away with a firing that would allow me to reuse the mold without repeatedly re- kiln washing.
I also tested drying the kiln shelf/ mold in the kiln (usually leave in kitchen for 24-48 hours) but took the kiln to 260 degrees for 20 mins (bung out) and just left to cool down as recommended on Warm Glass
I tried the slump float glass schedule on the KCR2 programmer as thiswent up to 700 as a high temp .
and got the following result:
The schedule was good enough to seal the bottle opening and left the bottle quite chunky. My feeling is that a hotter schedule is required.
I also put some other items into the kiln to see what would happen at this lower temperature to test a few other things:
- tacking bottle glass (green bottle thinner than Bombay Saphire
- whether pilot pens do indeed not burn off in the kiln
- look of glassline paints on surface or between glass