During below-freezing weather, the bar-chain oil generally used in chain saws may thicken up. The metal on a chain saw will tighten and dry up the bar and chain, which can cause friction. Chain lubrication is made more difficult for the chain saw and can cause permanent damage to the engine. In order to avoid this problem in cold weather, chainsaw users will winterise their bar chain oil by adding a thinning agent.
Wipe the chain saw's oil tank cap clean with a rag. Unscrew the cap and empty the bar's oil tank into an approved fuel container.
Clean the area around the oil tank to avoid debris and dirt falling into the tank.
Pour the amount of bar oil that needs to be thinned out for winter into the approved fuel container.
Pour the diesel or kerosene into the approved fuel container. Use approximately 2 per cent of thinning agent to the oil's overall volume.
Shut the fuel container and shake for approximately 30 seconds. Do not reopen the cap too quickly. Open it slowly to release any built-up air pressure.
Continue adding small amounts of thinning agent into the approved fuel container. Add 2 per cent increments each time. Close the container and shake for 30 seconds. Repeat the procedure till you have added approximately 5 per cent of thinning agent or till you have reached the desired consistency.
Refill the bar oil tank with the new thinned oil. Re-attach the bar oil tank's cap.
Test the chain saw by making a few cuts. Make sure to listen to the sound of the chain saw as it cuts. If the chain saw sounds too dry or the bar tip heats up, this means that the oil has been over-thinned. Simply add more bar and chain oil to the mix to thicken it.
Monitor the oil volume in the tank. Make sure the oil level is falling in consistency with the fuel every time the tank is refuelled. If the oil level does not drop, thin the mixture out some more.
Use your finger to check the consistency of the oil when you are adding the thinning agent. Make sure to clean your fingers afterward with soap and water. When the temperature begins rising, switch back to regular bar oil.
Over-thinning the bar chain oil can heat up the chain and bar, which will cause permanent damage to the engine. Do not thin the oil to more than 10 per cent of its volume to avoid engine damage.