DrWizard:
I'm looking for some cheap thermal adhesive to attach high-wattage ceramic resistors to an aluminum plate. "Proper" thermal adhesive is really expensive! I've seen some mention of overclockers using JB Weld on their CPUs. Since JB Weld is basically epoxy with metal shavings in it, it is electrically conductive. That won't be a problem though as long as I keep it away from the leads.Anyone have a better suggestion?
Normally there is thermally conductive grease, and some mechanical means of keeping the device
pressed to the heatsink - this allows replacement if the device fails. Electrical isolation is another
issue, usually solved with thermal pads which provide insulation as well and good thermal conductivity.
However for a resistor the risk of failure is probably a lot less and some sort of adhesive makes sense.
And resistors are usually isolated anyway.
You can just add fine Al or Cu powder to epoxy (as much as you can), giving a reasonable
performance if the joint is cured under some pressure. High temperature epoxy would be
a wise choice. I google, for instance: Thermally Conductive Epoxy Adhesives | Cotronics