/ Use heat to free up bolt. Can heat draw in penetrating oil? #11
My procedure - first try penetrating oil. If that doesn't work - apply heat to the nut.
I worked along side guys who were rebuilding the same tools as me. If the tool didn't come apart, they used the penetrating oil first. I would skip the oil, and go straight to the heat.
I always got more work done than they did. And, I didn't smell like penetrating oil, and burned oil smoke all day.
I only use penetrating oil to unscrew something, if it is the only option.