I need a rather large volume of oil to insulate a few 15 kV wires/coils. Unfortunately, the volume of oil required puts transformer oil outside of my price range.
I've noticed that others have discussed motor oil as a fairly economical substitute that works effectively around this range.
Are there any types of motor oils and/or materials inside of mineral oil that i should be taking into account when selecting a brand of motor oil?
As some background, the materials I'm insulating are made of copper with a few jagged edges. There're also a few little electrolytic caps and inductors.