Calculating oil weight depends heavily on the context. There's no single formula. The method varies depending on whether you're calculating:
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Oil weight for soapmaking: In soapmaking, you need to determine the total weight of oils used in a recipe. This is usually done by simply adding the weights of individual oils used. For example, if you use 100g of olive oil and 50g of coconut oil, your total oil weight is 150g. Websites like Auntie Clara's offer tutorials and calculators for lye calculations, which inherently involve knowing the total oil weight beforehand. Some soapmaking calculators help estimate this based on the desired batch size and superfat.
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Oil weight in a specific volume: If you need to know the weight of oil contained within a particular container (e.g., a tank, drum, or mold), you'll need the volume of the container and the oil's density (or specific gravity). The formula is:
Weight = Volume × Density
The density of oil varies depending on the type of oil and temperature. You can usually find this information on the oil's Safety Data Sheet (SDS) or through online resources. For example: If a container holds 10 liters of oil with a density of 0.9 g/ml, the oil weighs 9000g or 9kg.
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Oil weight in a mixture: When mixing different oils, you can calculate the total weight by summing the weights of each component. This is important in scenarios like blending oils with varying viscosities, as seen in resources like Widman International SRL's Mixing viscosities calculator.
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Oil weight for a specific application (e.g., engine oil in a car): The weight of oil needed for an engine is specified by the manufacturer. You typically don't need to calculate it; just follow the vehicle's recommendations. Information about useful load—including drainable oil—can be found in aviation contexts, as illustrated in the FAA document on Weight and Balance.
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Estimating weight of oil in a soap mold: In some soapmaking contexts, estimating the weight of the oil in a mold is done by calculating the mold's volume and then using an approximate density. The reference from r/soapmaking suggests a formula: Length x Width x Height x 0.4 (to get ounces). This is an approximation and depends on the soap's density.
A formula from an unknown source, (G.S.V.) x W.C.F. (in vacuum) x Sp. Gr./Density at 150C = Weight in M.T. seems to be a more specialized formula, likely for large-scale industrial applications. Without further context on the meanings of G.S.V. and W.C.F., it cannot be fully explained.
Therefore, the calculation of oil weight is context-dependent. Always use the appropriate formula and data for your specific situation. Remember to use consistent units throughout your calculations.
