The Boeing 707 as originally designed had electric de-icing boots on the horizontal and vertical stabilisers.
It was a rubber boot with the electric de-icing wires embedded in it, covered on the outside by a layer of stainless steel.
A problem arose when a lightning strike would hit the stainless cover and go on to burn a hole in the rubber boot thus severing the heating wires. The whole leading edge then had to be exchanged with a serviceable one.
Boeing did tests that showed that there was no need for tail de-icing and normal aluminium alloy leading edges were then fitted.