- Dec 29, 2016
- Reaction score
- Viet Nam
Yes, I was intending to make ceramic insulatorsGave some thinking of making a ceramic spark plug insulator. Skip firing and sealing. Dry out the green clay it will shrink. steel expands greater then the clay, but the clay before sintering may slump on the OD of the clay. The electrode will push the clay out so the sintered ID of the insulator will be bigger. In use the temperature will be lower then sintering so there will be a gap on the ID of the insulator to the electrode. On the OD of the insulator the steel cold if slumping occurred will compress the insulator and when hot that pressure will reduce and could turn to a gap. Ceramic is strong in compression. Thus the steel of the spark plug is unlikely to break the ceramic.
How to make the spark plug. If you can the use of a pottery kiln that is the easiest. Search for a place that teaches pottery even a school and get your plugs put into a firing and glazing firing. Else you can look up how to pit, sawdust, barrel fire clay. These methods are thousands of years old and you can learn how they sealed the porosity. A pit built like a rocket stove with a fan flowing in are is much hotter for the final step up. Note this is how they smelt steel for hundreds of years. So you get to glazing temperatures. There is also a very fast DIY glazing approach on the web. The problem is that the faster you heat up the ceramic or clay the more likely that it will crack. And a spark plug is not the ideal shape for thermal shock.
( I have "some" experience in firing ceramic and granite bricks ) , I have to make a kiln / smelting furnace before I can try to make it .