Scales For Biodiesel
Rick da Tech from B100 Supply
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What scales do homebrewers use in making biodiesel? The answers are endless, but if you follow a few guidelines in picking scales, it is possible to keep costs down. The smaller weights need smaller more precise scales, the larger weights need larger less precise weights. To reduce the amount of time exposed to lye and improve the accuracy of the measurement, it is better to
weigh all the lye in one weighing.
Preparing Titration Basic Solution
In order to achieve consistency I like to be as accurate as possible when weighing my 1-gram of lye. I prefer to be within 0.01 gram if possible. The Dixie Cup Scales can measure a gram of lye to this accuracy, so can several of the “Gem” Scales. Mechanical Beam balance style Gem Scales are available at the local smoke shops for under $20. Searching on the Internet, you can sometimes find them for under $10 plus shipping. Digital “Gem” Scales are also available for $30-$50 on the Internet.
Making Liter Batches calls for measuring between 4 and 10 grams of lye. I like to be within 0.1 grams to ensure consistency between batches. The Triple Beam Balance is a good fit here and will weigh up to 2600 grams if fitted with expansion weights. There are a number of digital scales available for under $50 that will give this accuracy. Lets not forget that many of the Gem Scales will reach up to 10 or 11 grams.
Bucket batches are typically 3 gallons (11L) of oil and need 50 to 100 grams of lye. Here I like to keep the same accuracy of 0.1g/L as with the Liter batches. This means an accuracy of at least 1 grams. The Triple Beam is still a good choice here providing 0.03grams/Liter accuracy. We can now also look at larger scales less expensive scales.
The 30-gallon (113L) batches of oil need 500 to 1200 grams of lye. To keep our 0.1-gram per Liter of accuracy we will need a scale with a 11 gram accuracy. The Triple Beam is still a good choice.
The 60-gallon (230L) batch need a scale able to reach 2500 grams. To keep our 0.1g/L we will need a scale with 23g accuracy. The 60-gallon batch is the largest the triple beam can do in one measurement. We are now able to use 1oz per division scales, which provide a 0.12 g/L accuracy.
The 90-Gallon (340L) batch is the largest homebrewing batch discussed here, and will need a scale able to reach 2500 to 3500 grams to weigh all the lye in one measurement. We also need only need accuracy of 34 grams. This places us firmly in the 1oz per division scales. To use the Triple Beam we will have to divide the lye into two batches to weigh.
The Retail column is the average Retail Price for the scale as of January 2005
are based on accuracy of the scale in gram/Liter for each batch
the lye can not be measured in a single weighing: