I fired a piece for full fuse on kilnwashed fiber board. The wash and board stuck terribly, though I managed to scrape most of it off, there was kilnwash left in the tiny impressions from the surface of the fiberboard and there was no getting it out of there. I read the tip to soak the piece in white vinegar and water, I did this, overnight. It worked wonders to free up the kiln wash, but it also left a pretty thick layer of vinegar crystals (so it appeared to me) and no amount of washing and scrubbing had any effect. Next I tried dry wiping the crystals away and this just scratched the surface of the glass. In the end I had to polish down the whole surface on the wheel which then exposed small holes where bubbles had been trapped beneath the surface. Arg, I am going to try and refuse it close the bubble holes.
What I am really curious about though is the effect the vinegar had. I used bullseye yellow, pink, and orange and Uruborus red. There was also a black stripe across the whole piece that was unaffected by the vinegar. Also unaffected by the vinegar was and old piece I had lying around that had kilnwash on it, it is a bullseye blue with green accents and it is fine (kilnwash even came off!).
If anyone knows what happened and how it can be avoided or fixed please let me know.
lissa.
Vinegar crystals?
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