Masking is an indispensable part of every powder coating job. Masking keeps the powder from reaching certain parts of an item and compromising its function. Since powder coating results in a relatively thicker layer than paint, it is critical to mask off sections to ensure seamless parts interlock. Some masking techniques have a creative application, adding to a product’s aesthetic appeal.
At Minnesota Industrial Coatings, we have extensive experience providing high-quality power and e-coating solutions. We use various powder coating masking techniques to deliver flawless products. Contact us today for all your powder coating needs.
What Is Powder Coating Masking?
Masking entails covering specific parts of an item with high-temperature masking tape during the powder coating process.
Masking usually follows the chemical pretreatment step of the powder coating process. Ensure the part dries thoroughly after the pretreatment process before covering the areas that require masking with high-temp tape.
High-temperature tapes are pricey but offer the best protection. Unlike regular masking tape, you can leave high-temp tapes on when blasting metallic pieces before coating. The tapes stay on during the spraying and curing stages and are only removed once the product is fully cured.
It’s advisable to remove the tape before the item cools down completely. At around 200° F, the tape peels right off to give you a clean, distinctive edge. Removing the tape while the part is too hot or too cool results in a defective finish.
Two-Tone and Multi-color Powder Coating Finishes
Masking injects a creative flair into the powder coating process. You can create products with two-tone or multi-color finishes by applying different colored powders to the same part. These special finishes call for slightly different coating and curing procedures, but they all require masking.
High-temperature tape or masking film guarantees exceptional two-tone or multi-color finishes. You should remove the tape after the part cools to 200° F. Once the coat is fully cured, you can retape the part and apply the second color. Ensure the part is fully cured before retaping, and wipe the bare metal surfaces with alcohol to eliminate contaminants from the previous masking.
You’ll need to re-mask and cure the part after each coat during each multi-color application. Always check with your powder provider if the powder you plan to use is suitable for two-tone or multi-color applications.
Powder Coating Masking Benefits
Masking during the application process keeps the powder from getting in the wrong places. It guarantees excellent results and eliminates potential problems down the line. Besides ensuring that you don’t create powder coating in the wrong places, masking has other additional benefits, including:
Improving Product Design and Aesthetics
Masking can be a creative process that improves a product’s appearance and design. Masking during the powder coating process is a popular way to achieve the two-tone design in wheels. You can achieve this popular look by powder coating the lip of the wheel and the spokes in different colors.
Masking powers this design feat by letting you section off the wheel before coating it with powder. That ensures that only the exposed parts of the wheel get the desired color. You then repeat the masking process when applying the second color to get a nice two-tone look.
Ensuring a Seamless Fit
Some parts are designed with recessed holes to facilitate assembly. The components that go into these holes have very tight tolerance, creating no room for errors.
Masking threaded holes keeps off the powder coat to ensure tandem components fit flawlessly. Powder coating a bolt hole impedes the ability to thread in a bolt and creates the additional work of removing the powder coat with a tap or thread chaser.
Safeguarding Electrical Connections
Powder coating doubles as an electrical insulator. An item entirely covered with coating powder doesn’t conduct electricity, proving problematic in certain situations. For example, starters and alternators must have bare metal surfaces to allow them to conduct electricity.
Powder coating an alternator without masking the connection points renders it useless. The powder coating insulates the alternator from the alternator bracket, and it can’t charge the battery. Failing to mask off a starter blocks the electrical connection causing ignition failure.
Facilitating Flawless Component Integration
Metal to metal contact is crucial when creating components with structural mating surfaces. Coating these adjoining surfaces with powder might interfere with their functionality, increase wear, and reduce the part’s lifespan.
Reducing Leakages on Gasket Surfaces
Masking off gasket surfaces before coating them with powder improves their integrity. Anything that uses a gasket to contain fluids – oil pans, oil and water pumps, valve covers, and more – should be masked off before powder coating. Failing to mask off these surfaces lowers the ability to create a leak-proof seal, leading to leaks.
Popular Masking Supplies
Here are some of the popular masking supplies you need for a flawless masking process.
High-Temperature Tape
High-temperature tapes are made from polyester and are the most popular powder coating masking solutions. They have exceptionally high melting points and don’t turn into goo when the temperatures exceed 400 degrees. Working with high-temperature tape can be challenging, but they’re easy to cut and leave a clean line.
High-Temperature Tape Discs
These are high-temperature tapes, precut into circular shapes. They come in handy when masking off sockets and other circular shapes. Tape discs save you a great deal of time, effort, and possibly carpal tunnel. Cutting regular high-temp tape into circular shapes is tedious and difficult. These discs come in various sizes to mask off differently sized holes.
Silicone Plugs
Silicone plugs are primarily used to mask off bolt holes. These silicone pieces are cone-shaped, come in various sizes, are reusable, and won’t degrade in the oven. The tapered ends allow them to fit into multiple hole diameters.
Silicone Caps
Silicone caps resemble the plugs, but they’re designed to fit over studs. Caps are not as commonly used as plugs, but they’re indispensable when powder coating items with attached studs.
Pro Tips for Clean, Crisp Masking Lines
Improper timing when removing high-temperature tape following a powder coating process can ruin your results. Removing the tape when the item is too hot causes the powder along the edges to flake off, leaving you with a jagged and messy line.
While the temperature inside the oven can be as high as 400 degrees, coating powder melts at 200F into a wet speckle stage. You can pull out the part from the oven and peel off the polyester masking tape with a scalpel, exact-o knife, or tweezers.
After removing all the masking tape from the part, you can put the part back into the oven and continue the coating process.
Get Perfect Powder Coating Results Every Time
The quality of materials and artistry employed directly impacts your powder coating finish. Minnesota Industrial Coatings delivers exceptional powder coating solutions using professional-grade equipment, coating powder, masking techniques, and supplies. We are a leading powder and e-coating service provider in Minnesota and beyond.
Contact us today to learn more about our durable and environmentally-friendly solutions!
