Updated: Aug 23, 2019
The many ways of sanding glass ...
Started with the clipper saw taking off the worst of it
The weight of the glass pushed the fibre paper that was lining the shelf down, but unfortunatly the paper lining the dam didn't move as well - I'd thought that because there was already a substantial weight of glass in the dam pre-firing that it would weigh it down enough to fix the issue. Also there are are few surface issues due to the fibre paper that didn't sink falling on the surface and leaving a shadow
Unfortunately the available flat bed sanders were either broken or out with my budget...this meant hand-lapping was the solution
Thankfully my mum and brother offered to help.
this is the back of the piece, you can see where the dip caused by the uneven kiln bed is marked with pen.
Next stage- reshaping and sanding the sides. Due to the issues with the fibre paper and the pieces fusing to the dams there were some fairly hefty chunks out of the sides, this meant that the shapes had to be altered slightly to remove them
Again initially the machines that I needed were broken etc, so ended up using a diamond grinding wheel that was slightly too small width wise for my pieces and then found that the finer grades were chipping the edges so had to go back to hand sanding
Tried using the broken belt sander - it was the pump that was broken, but due to the weight of the pieces, I wasn't able to consistently keep the belt wet enough to work properly and ended up cracking the tip of this piece which then had to be reshaped on the grinder.
With some of the pieces the curves were too tight making the grinder unsuitable
these had to be hand sanded
One of the technicians managed to fix the pump in the linisher so went to using that to get rid of the grind marks however I found while prepping a test piece for fire polishing that the belts were so worn that their grades meant nothing
The fine grade at the top is supposed to be the 80 belt and the rougher one is supposed to be the 120. The '80' was closer to a 220, which unsurprisingly was not coping so well with the grooves left by the grinder. So after getting the worst of it off using the 120 belt we went back to hand sanding, using diamond pads.
4 days later...
once edge reached a 600 grit I was able to see the bits that hadn't quite been sanded and used the diamond files to get rid of those bits before working my way back up through the grades.
diamond sticks grade 120
Pieces sanded to 1200
The whole process took roughly 140 hours with two people sanding 10 hours a day with help from a couple of others for about another 10 hours all together.
Next stage is fire polishing!