The purpose of cutting fluids and oils in engraving is to lubricate and cool the cutting tool. Additionally, the quality of the finished cut or work piece will be affected. Most “free machining” metals do not require cutting fluids, however, metals which are more difficult to cut such as stainless steel cannot be cut without cutting fluids or oils.
Different materials require different cutting oils or fluids to produce the desired result. When possible, consult the supplier of your raw stock. As with all oils and fluids, clean up will be a problem and may be more difficult than the actual engraving - especially if painting is to be the next step. Detergent is usually safe, but more violent solvent may be necessary. Experiment first.
Below follows a list of general guidelines for various material types and the recommended cutting fluids. Note: Materials not mentioned may or may not require any cutting fluid. Each application, tool and machine is different and results will vary.
Acrylic
Water with a small amount of dish detergent.
Aluminum
Emulsified or soluble oil. A good brand name is “Tap Magic” for aluminum.
Brass/Copper
Generally, engravers brass does not need require any cutting fluid, however, some softer and all harder brass will require some cutting oil. It is best to ask the supplier, but soluble oils are preferred. Note: Avoid cutting oils that contain active sulfur and chlorine, these will cause the materials to stain.
Flexible Engraving Stock
Engraving stocks require no lubricant. PVC-based materials tend to heat up easily, but compressed air is generally effective.
Glass
Water with a small amount of dish detergent.
Mild Steel
Emulsified oil. For simple jobs, even 3-in-1 will do.
Phenolic & Melamine
Air only. Any liquid will be absorbed into the material and will cause damage or delamination.
Stainless Steel
A heavy duty soluble oil is recommended.
Zinc
Same as aluminum.
Soluble Oils
Types of oils or paste compounds which form emulsions when mixed with water. Soluble oils are used extensively in machining both ferrous and non-ferrous metals when cooling quality is paramount.
Mineral Oils
This group includes all types of oils extracted from petroleum such as paraffin oil, mineral seal oil, and kerosene. Mineral oils are often blended with base stocks, but they are generally used in the original form for light machining operations.
