Q: I’m working in India with this example:
- The powder will cost 130 Rs/kg.
- The coating thickness is 70-80 microns.
In this situation, how can I calculate cost per square meter for powder coating (including labor, gas, and all things), and what is the standard cost per square meter for powder coating painting to quote any company?
A: In order to make this calculation, you must know the specific gravity of the powder coating. I can make an assumption to illustrate how to make the calculation. Please assume that the specific gravity is 1.6, and the average coating thickness is 75 microns.
- 1.6 g/cm3 x 75 microns = 120 g – micron/cm3
- Then divide 1,000 by the answer in “A” (1,000 converts microns and centimeters to meters and grams to kilograms).
- Therefore: 1,000 divided by 120 = 8.33 m2/Kg.
Of course, this assumes 100% transfer efficiency. If you are spraying the powder without reclamation and reuse, you can assume 60% transfer efficiency. This provides coverage of 5.0 m2/Kg.
Your cost per square meter at 130 Rs/kg will be 26 Rs/m2 (Rs refers to rupees). This is only the material cost.
To factor in the labor, gas, and other manufacturing overheard, you should first determine how many square meters can be coated with one man hour. (This will vary based on the parts coated.) Then calculate the cost of one man hour (wages, company-paid taxes, company-paid benefits, uniforms, meals, etc.).
To calculate the gas expense, it is best to use a meter on your oven and measure how much gas is used during a typical shift. Then divide this usage by the amount of product (in square meters) that was processed. You can then calculate the gas usage per square meter of product.
Next, account for all of your manufacturing overhead costs, such as electricity to run your finishing line, water used, maintenance of your process, depreciation of your equipment, etc. Last and most important is to factor in your profit on the hard work and valuable service that you provide.