For those of you that use your chainsaw's for ice fishing/spearing-do you replace your bar oil with a substitute for use on a lake? I'm completely new to the whole ice fishing/spearing thing. But I was quite suprised when the guys I was with cleared out their bar oilers and replaced it with vegetable oil for use on the lake. They said they were concerned about putting oil in the water. I wondered if this would be bad for the saw, and is it really that big of a deal.