Expert: Leisha Hiester - 3/7/2010

Question
I work in a chemistry lab.  I have new glazed crucibles that I have to number.  The number has to withstand strong acids and high temperatures.  What can I do?  Put a number on with a paint pens and clear glaze over that spot?

Answer
Susan,
What type of glaze is on the crucibles? You could possibly re-glaze the numbers on and refire. Use wax to set the numbers to hold their shape prior to firing.

There are "paint pens" as you say on the market. They're called Pebeo pens. There are two types;

I'm not sure which pen is better. They're usually marketed together. When I don't know my rule of thumb is to test, test, test. What I'd do in this case is try to purchase one of each & try them out. I think the only difference between them is that vitrea can also be used on glass and the Porcelaine come in fine points.

They are food safe once baked. I've read that they're supposed to be stored horizontal, not sure why, but makes sense.

They're durable once finished, but I am not sure if they will stand up to acids. You could consult with the supplier. Allow them to dry for 24 hours & place the piece into a cold oven. Set to 300 degrees & bake 35 minutes. Turn off oven, open door, but allow piece to cool inside oven.

My instincts tell me you're going to have to fire the numbers on to get them to stand up to your demands.

I hope this helps. Please feel free to write if you have any other questions.

One supplier I've used and like allot that carry pebeo pens:

www.bisqueimports.com
888-568-5991

Happy penning, love to see what you're doing.
Leisha