It also greatly depends on whether the
heat sink is held in place vis a screw / retaining bracket, or if the heatsink is held in place by an adhesive thermal compound. It's been a while since I have opened an NSI dim, but I believe there are serveral scrs that are all screwed to two seperate heatsinks. In that case all you need is a heatsink compound, < also called thermal grease> standard zinc oxide type would do. Remember these are only SCRs and not nearly as sensitive as say , a
socket 939 pentium overclocked 75%. It would be a lot more expensive but you could use the Artic Silver, or standard CPU heatsink comound. Remember you only want enough to fill in all the voids on the
SCR's faces. Having a bunch spilling out past the edges is wastefull and actually can increase the heat rentention of the component. Put a BB sized amounton the
SCR, press it against the heatsink. Pull it off to check for coverage across the entire component. Add more, if necesarry. Push it back on, wiggle it a little replace the
bolt or screw and you're in business.
Thermal grease, standard grade heatsink compund should be redily availible at Radio Shack, or a really good hardware store. If you don't have a handy electronics components store,< Frys,
etc> then try a hobby shop that does a lot of model trains and airplanes as often these places cater to guys that
build a lot of custom components for their rigs. Oh yeah RC Car guys use a good compound on the mounts for their
electric motors too. That stuff would be more than adequate for SCRs.
Happy hunting.