Expert: Sam Kelly - 8/3/2009

Question
A friend of mine recently lost most of her home in a house fire one thing that was saved were her porcelain music boxes and she very much wants to safe them. How would she clean the smoke damage off these? Thanks for any help I have looked all over the Internet with no help and cam across your site! Hope you can help!
Mindy

Answer
Hi Mindy, whats happened is actually a recognised firing process, called 'Black Firing'. The carbon from the smoke along with temperature at 600degC allows unglazed areas of a pot to absorbe the carbon. I have recorded wood fires in an old 'Webber Bar-B-Q' at 850degC.

If the smoke effected parts are on soild glaze then it should just wash off, if the glaze is crazed and un-glazed areas have absorbed carbon then the only option is to re-fire to burn the carbon out.

Pick the worst piece and fire to 700degC in oxidation using the same firing schedule as a bisque firing, you arn't looking for a glaze melt, just the burn out of carbon. Needless to say if there is any decals or lustres on the box/lid there is a very high probability they will vanish, testing of the worst effected piece will tell you. If some carbon burns out at 700 but is still evedent go to 800, good luck.

Sam