Enamellist Merry-Lee-Rae wanted to know how well the new PMC Sterling fires in the home-made stainless steel foil containers. These containers do not flake, scale or oxidize, in the kiln after being heated. So, I set out to find out some information about the foil, made my own container, and then fired some PMC Sterling.
After researching the American Iron and Steel Institute’s handbook, High-Temperature Characteristics of Stainless Steels, I found out that there are two types of stainless steel foil made especially for heat treating items in kilns. These foils are listed as number 309 and 321. Foil 309 has a higher rating and can be fired up to 2000˚ F (1093°C) without scaling. Foil 321 is good up to 1500˚F (816°C).
I found I can purchase a whole roll 12” x 10 foot of foil on line at Grainger. The 309 is more expensive than the 321.
- 309 comes in a length of 12” x 10 foot for $87.40 and can be found at http://www.grainger.com/Grainger/Foil-Roll-4UGL1?Pid=search
- 321 comes in a length of 12” x 10 foot for $28.00 and can be found at http://www.grainger.com/Grainger/Foil-Roll-4UGL5?Pid=search
Now onto the test. . .
My sterling silver piece came out perfect.
And the box? It held up fine and no flaking!