True, Mike and 046. Good time to discuss this. At these bitter, low temperatures, a lot of companies just stay home. Not us, though.
Here are some things to consider.
Vegetable (
soybean) oil and
corn oil will reach their 'freezing point' and turn into a gelacious slurry. This temp is somewhere around 18 to 24 degrees F (~ -8 to -4 C) for these two oils. Further temperature drop and the pourable slurry goes from pourable to 'squeezable' (see the picture below taken at 15 degrees F (-9.4 C)).
Canola, on the other hand, has a much lower freezing point, and a wider range between where the the oil goes from liquid oil to an easily pourable semi-liquid and then to a 'squeezable' white semi-solid. I've found this low-end 'cutoff' temperature of Canola, where you actually would choose to put it in the cab of your truck, or bring it in overnight, to be in the range of zero to around 5 below zero Fahrenheit (-18 to -20 C).
Be aware of this, though. Only a few degrees increase (like warming your saw up) and the veggie liquifies. One of the benefits I see is that veggie oil has a
very consistent viscosity throughout the entire temperature range of where we'd use it, right down to the very low temperature point where the slurry goes from pourable to extrudable.
Regular bar oil, on the other hand, the viscosity changes greatly as the temperature drops. It gets thicker and slower to pour. This is ONE reason we have to cut it with diesel in the Winter, or use a Winter formula bar oil (already cut with a petroleum-based thinning agent). For the guys who run regular-weight bar oil in the very depth of Winter, there is a big reason you 'cut' your oil with a thinner. Aside from the annoyance of having to wait for the slow, thick bar oil to flow from the jug and into the bar tank, you should consider the thickness of the oil already present in the oiler system. It flows with difficulty until the temperature comes up. Our impulse is to fire up a cold saw, gun it a few times and begin cutting. When gunning a cold saw, your clutch drum is driving a plastic pinion gear, which meshes with a plastic oil pump gear. If the petroleum bar oil is cold and really thick the stickiness of the tack combined with the thickness of the cold bar oil give resistance to the pump parts, rather than lubricity as what you would think. The clutch-driven pinion gear is going to move without any resistance whatsoever because there's a motor and a clutch drum driving it. The oiler pump gear, however, if it offers much in the way of resistance, one or the other or both of those gears can strip. Then you have no oil being pumped, no lubrication to the bar and your saw is down within a few minutes with hopefully no damage to the bar. I can't think of a worse time for a saw to go down.
Veggie (esp. Canola) with its consistent thinness down to very low temps, and no need to modify it, is what I consider to be a major advantage.
In an upcoming post I'll gladly share a few simple ways to adapt to the characteristics of veggie at temperatures below 10 degrees F (-12 C).