With the increased cost of saw oil, it is all the more important to reclaim the dirty oil in your saw, not to mention the ecological imperative to minimize this type of waste. As we all know, oil doesn't wear out, so if we can keep it clean, it will last indefinitely.
During a recent Open House we held at our shop, a system used in a large southwestern lapidary recreation room for an R.V. trailer park was related to us.
According to Don, these people reclaim 85 to 90 percent of their oil with this process. The R.V. folks use a stock tank on legs fitted with a false bottom made of expanded metal, elevated a foot or so off the bottom of the tank. A valve is installed in the bottom of the tank to drain off the clean oil after processing. When their saws get dirty, they clean out the sludge and pour it into a common ordinary paper grocery bag(s) set on the expanded metal false bottom of the stock tank. The oil is filtered as it seeps through the sides of the paper bag leaving the sludge in the bag and the cleaned oil in the bottom of the tank.
Another tip for reclaiming saw oil calls for the use of two five gallon plastic buckets. Drill a number of 1/2" holes every two inches or so in the bottom of one of the buckets. Place one large paper grocery sack in this bucket, which will act as a filter. Place a large metal coffee can in the bottom bucket to keep the top bucket suction free and easy to lift and drain off the oil in the bottom bucket. Pour the dirty oil in the paper sack and let it drain. Warm weather or a heated shop will speed up the process. Trim off the edges of the paper sack and cover the five gallon bucket with a bucket lid or place a piece of cardboard over the top to cover the oil. Drain the oil, easily, from the bucket as it collects by switching the top bucket to another bucket and then continue the settling or filtering process.