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



My friend gave me a bag of empty Bombay Saphire bottles so I decided to test schedules for flattening these bottles and for flattening broken bottles for making into other items.

Before and after pictures below.


The schedule used worked well. This was the ‘wine bottle flatten’  glass campus firing schedule:

rate 200C to 535C hold 20 mins

rate 500C to 815C hold 30 mins

rate AFAP to 535C hold 60 mins

rate 200C to 150C hold 0 mins


Next project / test was to just slump a wine bottle flat. Has to be done, everyone does it and wanted to see how it came out. Not expecting to

particularly like it.  I had originally wanted to do flat glass tiles with wine bottles, but after the difficulty of

cutting them (have decided to try and watch out for a second hand creators bottle cutter before I attempt again) I thought I’d try another way.

So, in with my bottle to slump flat, I also took a hammer to a second bottle (bottle put inside 2 ‘bags for life’ , covered in cardboard and tapped with a hammer. On the second ‘tap’ the bottle broke. I was hoping for large pieces of bottle to slump flat – the idea being to get some decent sized glass pieces to slump flat that could then be cut into shapes and refired to make something ‘completely different’.

Firing schedules for bottles are a bit of a minefield and the KCR2 controller does not come with a bottle slump schedule (it has a bottle firing schedule – but not clear what this is for). I therefore googled a few schedules online and picked one to try. I went for the ‘wine bottle flatten’  Glasscampus schedule.

The results were a nicely flattened wine bottle. (Confirmed it’s not really ‘my thing’ and not sure what I would really do with this). But, the schedule seemed right for wine bottle flattening, should I wish to do this again. However, for the pieces of glass (which were half the thickness of the wine bottle) the schedule was maybe too hot/ long as it had given the pieces long enough to try and become 6mm. These also stuck to the Papyros paper more than the flat wine bottle. I’m wondering if there is a schedule that will be able to slump the pieces flat , without bringing them to a full fuse temperature as much as this.

However, on testing, the pieces will cut (on flat side) quite nicely and so the concept of producing flat pieces that can be cut up and made into other pieces looks feasible. Just got to work on the firing schedule.


I put the remainder of the broken bottle into a second firing. This time I used the Glass with a Past ‘flat bottle glass’ schedule. As you can see this was just enough to flatten the glass, without rounding edges. Some pieces are not entirely flat. With a bit of a tweak (either holding longer or higher temp?) this is probably a good ‘flattening’schedule to avoid overfiring the glass and to keep it thin.


Schedule used (courtesy of glass with a past)

149/hr to 260C for 10 mins

260/hr to 727C for 8 mins

FULL to 571C for 20mins


For my next project I wanted to have a go at recycling wine bottles and had started reading and researching. I wanted to steer away from the slumping bottles trend and ideally was looking at how I could turn a bottle into something else. In my mind there were two avenues to explore –

  1. turning the bottles into bits / frit that could then be fused together / used in molds
  2. turning the bottles into glass sheets that could then be cut and made into other items

My conclusion was that the best way to do 1. would involve either taking hot bottles out of the kiln and plunging into cold water in the thermal shock method or smashing bottles with a hammer and putting through a frit piston (along with the dangers of all of the glass dust created). I felt that I was not ready to do either of these yet as my confidence in using a hot kiln or handling lots of glass dust was just not there yet. I also suspect things like using a frit piston will be easier being done outside in the warmer weather.

So, I turned my attention to 2.  That is, creating glass tiles / sheets from bottles that hopefully could then be cut into shapes etc to create other items. In pursuance of this I collected together some wine bottles. Soaked and cleaned them. Despite adding bicarbonate of soda,  vanish and white vinegar to the warm water, the labels either slid off easily ( bottles of Ned) or stubbornly stuck fast ( bombay spice). There definately must be a better way to remove labels! The internet claims anything from just soaking in water and soap   to using bicarbonate of soda, borax and white vinegar. Ones I haven’t yet tried are olive oil and nail polish remover.

Those bottles where I had been able to remove labels from were placed in the oven to dry. I had purchased a glass bottle cutter from Amazon a few days before. There were two dominant types online. One being a circular cutter type design, the other being a lie-down cutter. Both had good reviews and I just picked one to try. My aim was to follow this method or this alternative method (both on glasswithapast) for creating flat glass.

Unfortunately on my first attempt at using the bottle cutter, the glass bottle shattered when trying to score it and left me with a nasty gash on my arm.

I decided to take a rain check to up my safety protection for cutting bottles and have ordered a face shield, cut resistant gloves and sleeves in readiness for a future attempt once my arm has healed. It also made it very obvious to me that none of the tutorials / youtube videos I had seen demonstrating the glass bottle cutters had shown / used or even suggested the use of safety equipment. (I had been wearing my safety goggles, but had reserved my gloves until the actual breaking the score line part). The lesson learned for me is that bottle glass is not predictable and I’ll certainly be wearing hand and arm protection all through the process in future in addition to eye and face visors. This youtube video does show the use of gloves, goggles and mask and is a bit more comprehensive than some of the other instructions I have seen.