WarmGlass.com

Hi all

I've made a plate ready for slumping but have found marks on some of the colours of the glass.

Its two layer white BE with 1.2 colours laid ontop and fully fused slowly. The discolouring only seems to be on some of the opal colours, like dark plum, one of the purples (don't know which), orange and red. Hopefully the photos will catch what I mean.

Also is there a way of removing this, eg using a diamond hand pad to rub it over and then devit spray and fire again.

Thanks for your help.

Tracey

In my experience opals are more prone to devit than transparent glasses. So, you have to make sure the glass is perfectly clean before firing.

Yes you can use a hand pad and water, or even wet and dry sandpaper, again with water to abrade the surface. Clean very well, add devit spray if desired. The devit spray I use is a solution of borax (without the additives).

Try spraying and refiring first. I've "cured" devit on certain opals by doing that. You have to fire to about 1425° to cure the spray.

The devit that shows in the OP's pictures is in rectangular shapes - or so it seems to old eyes. Is this typical/normal? Or am I perhaps mistaking a reflection of some sort as the devit in question? Here's a screenshot where I've identified what I perceive to be a corner of one of the rectangles:

Thank you for the replies, I will buy some devit fluid and try it.

The worst of it is around the edges of the rectangles, as though its the sides of the coloured glass that have flattened in firing and devitrified.

The bit you identified David is a reflection though as that rectangle is fine.

Thanks for all the help though.

Best wishes
Tracey

If you did any grinding to your edges, that could be what you're seeing: grinder scum.

I've noticed that some opals, when full-fused, seem to show a different color on the top than along the flattened-out edges. Not devit,just a slight color difference.