I guess I should consider myself fortunate. I got a gallon of silicon oil from work. It is use to keep the HV electrodes cool that make ozone for our DI water system/PW500. I put it in my old Heathkit Cantenna. One thing I notice is that I should have created a reservoir and installed a circulation pump. It makes a hot spot about in the middle of the can. Circulating it I probably could have made it capable of 2KW rather easily.
I have never seen a price list for the spare load resistors for Bird Loads. I presume that the prices are horrendous.
When I inquired about overseas shipping of the Bird Load Silicone oil, it was almost more cost effective to buy a new load.
Long term as suggested Water or Air cooling is the way forward.
When I was looking for EMC amplifier loads and replacement Water cooled resistors this company was the most accommodating, communicated and quickly quoted prices. I dont know if they are still? around.
This company also sell proper high voltage surge resistors? for power supplies used in many broadcast transmitters.
When I checked their dimensions and part numbers they appeared very similar to the Bird and Altronic part numbers. Their physical sizes also matched the load resistor in many loads.?