I've used it on bisque with no flaking (see my previous post). I should probably add that I bisqued to about cone 09, so the piece was fairly pourous. It may also work if you bisque higher, but like Bruce says, try a test piece first.
Sorry I missed that part on your previous post Pieter. I'm going to try it on the piece it flaked off on…..can't hurt and it's non-saleable as is so it will be my test piece.
- Pieter Mostert likes this