Amaco Velvet Underglaze + Zinc Free Glaze

[Marie1234]

Hi,

I have recently bought Amaco velvet underglazes. I was planning on using them on bisque stoneware plates (bought from a wholesaler). Because I want the plates to be dinnerware safe, I thought of buying Amaco’s Zinc Free glaze (HF9).

Can I apply the underglazes to the bisque stoneware, let them dry, apply the glaze and then fire? (So only 1 fire overall)

I emailed Amaco about this but they were not helpful, they only said the approach above would smear the colors. Is this true?

thanks.

[Min]

Hi Marie and welcome to the forum!

It is possible to gently dab on a thin coat of brushing glaze with a sponge onto unfired underglazes then once that has dried apply subsequent coats with a brush but you do run the risk of smudging the underglaze. The other reason it's a good idea to bisque fire the underglaze on is underglazes contain binders that can inhibit the glaze absorption, by bisque firing it prior to glazing the binders are burned off. I have found some underglazes actually have enough flux in them to start glossing over at cone 04 so if you haven't used these underglazes and glaze together before I would do some test tiles to see how compatible they are.

[Gazal]

9 hours ago, Marie1234 said:

Hi,

I have recently bought Amaco velvet underglazes. I was planning on using them on bisque stoneware plates (bought from a wholesaler). Because I want the plates to be dinnerware safe, I thought of buying Amaco’s Zinc Free glaze (HF9).

Can I apply the underglazes to the bisque stoneware, let them dry, apply the glaze and then fire? (So only 1 fire overall)

I emailed Amaco about this but they were not helpful, they only said the approach above would smear the colors. Is this true?

thanks.

Hi Marie, based on my experience you'd always get a better result if you fire your piece after applying underglaze. sometimes in the past I have glazed on underglaze without firing it first and the glaze went very rough and not smooth over the under glaze. This is what I've experienced before for some colors more than others.