michaelblock posted:There is an "insulated strip" at the horn battery bracket mount. Is that still needed when the sheet aluminum is screwed down? If so, why? Thank you again.
Nah. In fact you really don't want to use insulation as the heat sink on the board will conduct heat to the aluminum sheet, which should then conduct heat to the frame of the locomotive. The insulation would prevent that from happening as easily.
As an aside I've had good luck using this thermal paste between the heat sink on the AC/DC/Cruise Commanders and what ever they are mounted to: http://www.arcticsilver.com/as5.htm
