JohnO's Bucket Biodiesel Mixer

By Rick Da Tech


JohnO's Bucket MixerIn the search to find the safest and easiest to use bucket processor, this one stands out above the crowd. It was designed years ago by Johno, an industrial design engineer that hangs out on the infopop forum. It uses a shaded pole motor attached to the lid so that the lid must be on the mixer before it will work. The motor shown in the photo is a brushless shaded pole motor from for under two bucks. The shaft is a steel rod from the hardware store and the prop is a bit of copper tubing soldered to the end and smashed down in a vise. The blades are angled so it pushes the biodiesel down to the bottom of the bucket.


CAUTION: This design leaks lots of methanol vapors, especially when the lid is off. Only use it outside in really well ventilated areas, well away from flame. The flammable fumes are toxic, but are also dense enough to stay close to the ground while cold. Take precautions to avoid them.

Here are Johno's instructions for using his mini processor:

  1. Heat not-quite 5-gallons oil using a turkey cooker to 55degC or until boiled dry (250degF) Watch out for fires and keep the methanol sealed up and away from the flame.
  2. Titrate
  3. Completely away from flaming turkey cooker, pour 3/4-gallon methanol into the plastic bucket, dump in the proper quantity lye
  4. Snap on lid and mix until the lye's dissolved (10-30 minutes).
  5. When the oil is no hotter than 55degC/130F, pour it into the bucket with the methoxide, snap the lid back on.
  6. Let it mix for at least 30 minutes
  7. Unplug the motor and cover it with a blanket to hold the heat in.
  8. In a couple hours you can pour out the well separated methyl esters (ME).
  9. The glycerin will be in the bottom, still liquid if you haven't waited too long. It isn't much trouble if it has solidified - just scoop it out, wash and dry the bucket, and it's ready for the next batch.

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