[Shop-talk] Drilling through a spark plug to make a christmas ornament?

[Benjamin Zwissler]

I'd say if the spark plug was constructed properly you'll have a real bear
of a time getting the conductor out.  Everything is installed through the
top with the inner electrode subassembled into the white ceramic insulator
first. The assembled white ceramic insulator is then placed in the steel
housing with some sealing material and then mechanically retained with a
crimp.

This is a good overview:
https://www.denso.com/global/en/products-and-services/automotive-service-parts-and-accessories/plug/basic/structure/

The center copper electrode is retained in the ceramic insulator with a
ceramic powder that is solidified with pressure and heat.  They're not
supposed to come out even after hundreds of thousands of combustion cycles
exposing them to high heat and pressure.  The most common failure mode is
the steel housing is damaged from over-torquing and then the whole ceramic
center assembly blows out during combustion making a nice dent in the
hood.  Knock can cause damage to the ceramic and the electrode but rarely
does that cause anything other than misfire.

Drilling out the center electrode would be my only recommendation, but I
suspect that won't be easy either.  I the bit gets out of the center and
contacts the ceramic its likely to get dull rapidly and its a long narrow
channel that would require really tight alignment.

Ben....

On Fri, Dec 14, 2018 at 8:01 AM Jim Franklin via Shop-talk <
shop-talk at autox.team.net> wrote:

> While lying awake at 0-dark:30 I had an idea of turning old spark plugs
> into ornaments by inserting blinking lights in them. I thought for sure it
> would have been done but I can't find anything out there in Internet land.
> Is it possible to pull out the center electrode with hand tools and a vise?
>
> thanks,
> jim
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-- 
Ben Zwissler
bjzwissler at gmail.com
Columbus, IN
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