oxides over bisque without 2nd firing

[rel]

I recently covered a stoneware cone 10 piece in heavy black iron oxide,  I then washed it all off, changing my plan. The resulting bisque piece is super gorgeous, showing texture etc,  and it was suggested by a few other potters to leave it the way it is.   Don't glaze and fire again.  My question is : will the oxide "powder" eventually wear off?

And also, my desire now is to cover the piece in clear water soluble non yellowing varnish that I use on my paintings. I have done this before on bisque ware and the result is great when it is a decorative piece, and I am not using glaze but want a smoother surface.

BUT, will the oxide fade even thru the varnish?

Suggestions....thank you

[Callie Beller Diesel]

If your piece is sculptural or decorative, there’s no problem with using your non-yellowing varnish. 

While I’ve seen some instances of copper washes or copper based raku glazes re-oxidize and change colour over time, they don’t fade.  I’ve not seen it happen with iron based pigments however.

Worth noting that raku artists who know about this phenomena will varnish their pieces to prevent it. 

[rel]

Thank you,  i found some pieces  that i had rubbed with the black oxide and then used the varnish. I did this 3 years ago, just found,  and they are fine.  Think I'll go ahead.