Re: old spark plugs; specifically green Splitdorf's

[Steve Swan]

i took apart a green Splitdorf spark plug to clean it as well as see the different parts. it came apart easily. one of the parts, what i would call the electrode appears to be all metal, but i certainly could be wrong. the intriguing part of the electrode is what we know as the ceramic part of a modern plug, where the metal tip sticks out through ceramic. This part of the Splitdorf, we would normally expect to be ceramic is clearly a type of metal and in fact appears to be plated, as there are several areas where the plating is obviously worn away. Who knows what this metal this plating is made of and is it necessary for the plating to be intact for the spark plug to fire properly? i hooked the plug up to the plug wire on my little old Yamaha and have a nice fat spark. i just would like to learn a bit more about these old plugs.... can't think of a better way to spend my time.......!

20180713_223357.jpg

[Robert Luland]

Steve, all they had was electroless nickle. It was for only one thing to prevent corrosion. No hard chrome, no nothing. Bob L

[Steve Swan]

Steve, all they had was electroless nickle. It was for only one thing to prevent corrosion. No hard chrome, no nothing. Bob L

Thanks Bob. probably the only true test if the plugs any good is to see if the engine will run with it.

[T. Cotten]

Steve, all they had was electroless nickle. It was for only one thing to prevent corrosion. No hard chrome, no nothing. Bob L

How old are these plugs, Steve?

Electroplating nickel began around 1840.
Electroless wasn't perfected until after WW2.
(Wikipedia)

....Cotten

[Steve Swan]

How old are these plugs, Steve?

Electroplating nickel began around 1840.
Electroless wasn't perfected until after WW2.
(Wikipedia)

....Cotten

i would say this "green hex" Splitdorf was sold new during the late 'teens and throughout the '20's. i have been lurking on various spark plug collector sites, have learned the ceramic insulator we see on today's plugs was commonly rolled mica back then, so that would explain the "plating" i thought i was looking at, in fact layers of mica.