Hopefully someone can help with what I'm seeing here in this glass. Im not sure if it is devit or possibly from cutting with the tile saw or wrong schedule. Have only been doing glass work for under a year but doing plenty of projects and experimenting. Sorry for the long post but trying to give all the details.
Anyway here is how this became what you're looking at.
Started out making 4 different flow slabs all at 3/4" thick of various lengths and widths. They all looked good coming out of the kiln and even after cutting up three of the four. So not thinking it is from the flow slab melt. Here is the flow slab schedule I used and have used before for flow slabs of similar thickness.Fahrenheit temps.
300 1225 :45
600 1525 1:30
AFAP 900 3:00
45 800 :01
81 700 :01
AFAP 70 :00
Kiln is an Evenheat Studio 24 with side and top elements.
Cut these pieces up on Dewalt tile saw into 1" wide strips that were 3/4" thick. The blade is the 10" Husqvarna Superlok I bought from HIS Glass. Very good cuts.
After cutting each piece, it was laid in water and then cleaned again at the sink with soap and water and individually dried. Before putting in the mold for the plate melt they were cleaned again with alcohol. I did not sandblast the pieces as I have not had a problem with this on another projects. Did a lot of research and it's about 50/50 out there on whether or not to sandblast.
This particular flow slab and plate in question is from the following BE glass material
0345 "steel jade"
0132 " driftwood grey"
Sorry but did not get a photo of the arrangement of blocks to make this plate but it was laid out in a snowflake pattern. Basically a cross but also rows in between the 90 degree cross at 45 degrees.
The shelf used is mullite with BE kiln wash on 1" kiln posts and the mold I made from Insblock 19 fiberboard that was sanded, cleaned and coated in BE shelf primer (4 coats) with 1/8" fiber paper around border. The mold circle was cut to 10-1/4" so I would end up with a 10 circle. The fiberboard mold was 12" x 12" x 1-1/2".
Schedule for 10" circle plate with 1125 grams of glass to achieve a 3/8" thick plate is as follows.
300 1225 :45
600 1525 1:30
AFAP 900 1:30
100 700 :0
AFAP 95 :0
Overall everything looks pretty good but you can see some slight hazing and lines that look like clear film laid over the glass but just the outlying edges of the clear film. Almost all of these are on (or over top of) the "0132 "driftwood grey" color. It is not noticeable until held under fluorescent lighting.
So my question is after all the details is what caused this? Glass, schedule, tile saw cuts or something different?
My next question is how do I fix this? I am thinking of sandblasting the whole top layer with Alumina Oxide 120 to get get rid of these areas.
Do I then re-fire the whole piece (back in the dammed mold) or after sandblasting it, putting it in the bowl slumper and achieving a fire polish.
I have sandblasted pieces but not done a fire polish finish on any pieces so while I know this won't destroy the piece, trying to go about do the right thing asking question thus saving time trying several other things.
BE site and subscription to videos have been a tremendous help in the learning process.
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