On Apr 1, 6:14*pm, " wrote:
I've been using engine oil as a coolant for high power resistors but
am wondering whether something like peanut, sunflower or avocado oil
would be better. Engine oil gives off an awful smell when it breaks
down, smells like rotten eggs. Can't find transformer oil. Any
thoughts?

Yucky things will grow in vegetable oil. May I suggest hydraulic oil?
The only additive is anti-foaming stuff. Hydraulic oil can get really,
really hot before it begins to break down. You are probably smelling
additives in the oil, not the oil itself.

Can your oil move up through the resistors as it gets hot?

Paul