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Glazing a crucible

Hi, I want to melt gold in a ceramic crucible. I was told to glaze
the crucible first with borax powder. How do I do this? I’ve tried
to melt some, and whatever didn’t fly away formed a burned looking

Michelle Barrineau

    Hi, 	I want to melt gold in a ceramic crucible.  I was told to
glaze the crucible first with borax powder.  How do I do this? 
I've tried to melt some, and whatever didn't fly away formed a
burned looking lump. 

Nobody ever taught me, so I may be doing it way wrong, but here’s
what I do…

First, blow air through the crucible to clear out any dust and
particles that may be sitting in there.

Then put the torch on the crucible to warm it up, not super hot or
anything, but just a minute or so on a low torch setting.

Sprinkle in the borax powder. Because the crucible is hot, the borax
should melt some and stick.

You can now put the torch onto the borax until it melts. Putting
some silver into the crucible may help a bit, since you can direct
the flame onto the metal, and the heat will conduct through the metal
into the crucible rather than depending on the direct flame of the

Again, there may be a proper way of doing this, I just happened on
this by trial and error, and I’m unschooled.

  • darcy

Hello Michelle: Try heating the crucible up with the torch first.
Then sprinkle the Borax powder all around in it. Then heat it again
moving the torch around until it looks like it is glazed. Repeat
this until you have a good coating all the way to the edges and over
the pour spout. Don’t worry if it takes on a brown color. As the
crucible cools the glaze will crack and that is ok, it will melt back
together next time you heat it. Another tip is that when you want to
add borax to the metal melt. Heat the end of your stir stick slightly
and dip it into the borax container and then stir it in. This will
keep most of it from fling away and also allow you to keep the flame
on the melt to reduce the oxygen absorbed.

Michael R. Mathews Sr. Victoria, Texas USA

Hi Michelle, heat your crucible without adding borax… when its
hot enough press your borax cone into it and remove, continue
heating till you get as nice glassy look. If you don’t have a borax
cone and are using powder, do it the same way except when the
crucible is hot sprinkle in your powder.

Ed Dawson
Maine Master Models

Hi Michele, You can grind away your first attempt with a heatless
mizzy wheel on your foredom. Use an oxidizing flame (it will hiss a
little) With a circular motion heat the whole crucible till it glows
bright yellow. (You are wearing tinted goggles, right?) Sprinkle a
few pinches of borax from about 8" above the crucible. You can also
"throw" a pinch where it is needed. After a pinch or two re-heat the
crucible so the borax melts in. Repeat the process until the whole
crucible has a slight shine. It should not be driping with flux when
it is red hot. Goog luck. John, J.A.Henkel Co., Inc. Moldmaking Casting

I assume you are using an unglazed 'scorifier and not a laboratory
glaze d one. Just rub the borax into the wettened crucible and add a
pinch or tw o for luck. The fact that you ended up with a lump
suggests you haven’t heated it up sufficiently which does not auger
well well the gold smelt! When the crucible begins to glow red the
borax should have assumed a hone y like consistency. Just swill it
round the crucible under the flame. If y ou can’t control your flame
then begin heating the crucible from underneath!

Personally, I just dump in some borax and heat it up.

David valentine

This is how I glaze a crucible for its initial use: Mix borax powder
with either water or alcohol until you have a thick slurry. Paint it
in the crucible where you want it to glaze. In the case of the
alcohol preparation, touch a lighted match to it to fire off the
alcohol first, if it hasn’t already evaporated. Then, for either the
alcohol or water slurry, heat the crucible up until the borax
liquifies. This method puts an even coating on the crucible.

Well, get the crucible red hot and sparkle some box in the crucible.
It will look like the 4th of July… a lot of pretty colors and when
you remove the flame you will see the glaze in the bottom

Andy "The Tool Guy’’ Kroungold
Sales/ Tools/Specialist
Phone 800-877-7777 ext. 4194-4191
Fax 337-262-7791