I'm guessing the natural rubber is blended in as a tackifier? If so, I can see where that would cause trouble - rubber cement.
I also guess that the tackifier used in the dino oil mainly used in the US is not green enough for use where biodegradable oils are required (dino oil IS biodegradable, but don't get me started).
Good to know about the gumming properties of the bio stuff. I'll stay away. I see the same gumming tendencies with the oil used in my fryer, so it will be interesting to see if plain canola/rapeseed is any better in that respect.
I did a lot of sawing before bar oils were common - with SAE 10, 20, or 30 motor oil. Sometimes with ATF to keep it flowing. I didn't have bar problems unless the oil stopped flowing because it was too cold, or the tank ran dry from the thin oil warming up. But I attribute the good results mostly to good bars and Windsor tips.
Now I'm using dino bar oil, and I've had mixed results. Still ok with the good bars, but disappointing with the tips of cheaper bars. Still, the tackifier seems like a good thing, esp. on a 36" bar, so I use the bar oil. I cut it as needed with used ATF or motor oil to keep it flowing in the cold, or just to extend it and get rid of the used oil for the small bars.
I've found that filtering clean used oil through used fuel filters from my injected vehicles produces good results. I know it's cleaning it up because the filters plug up after about 5-10 gallons of old oil. Clean enough for fuel injectors is clean enough for a saw oil pump in my book. And no problems with the saw oil filters this way either. Pondering using a bypass type filter for this duty... but may be a solution in need of a problem.
Have the people reporting better results been pumping a larger quantity of the cooking oil because it's thinner? Could that be contributing to the good results? Or have they adjusted for that?
