Masking

A: Lots of tapes can help achieve the basic purpose of masking – ensuring that coatings are applied only where they are supposed to be. But masking tapes can also increase your shop efficiency. The right tapes can save a lot of time, as technicians can apply in one piece without having to continually re-start the tape due to breakage. The tape will also apply with fewer wrinkles and unnecessary overlaps that can compromise the mask. Look for masking tapes with release coatings or similar features that help the tape unwind smoothly and consistently, and a primer layer that anchors the adhesive to the backing. Similarly, masking tapes are available with adhesives formulated for clean removal from all automotive substrates including rubber or glass, without leaving adhesive residue that must be cleaned. They will also remove much more quickly without small pieces of backing remaining on the substrate, especially on jobs left overnight or over the weekend.

A: Yes. Cold temperatures stiffen the tape adhesive. This means it can require more pressure to adhere immediately to the surface, and more time for cleaning adhesive transfer after removal. Conversely, higher temperatures soften both the backing and the adhesive and cause the tape to easily stretch. This means that the adhesive must cover a larger area, lowering its effectiveness and making the tape less reliable for sharp paint lines. Humidity is a particular problem, as it can cause condensation on the panel surface; many masking tape adhesives do not perform well in water.

A: Instead of a combination of plastic and paper, we recommend premium plastic sheeting as it easily pays for itself in masking time and reduced rework. Reusable, untreated plastic and paper sheeting from around the shop will normally have dirt or dust particles on it and can easily introduce those contaminants to the paint job. It also does not prevent dried paint from flaking off and contaminating the fresh paint job upon removal. You can counter this by using smaller pieces of masking paper along with the sheeting, but that can be time consuming.

Instead, premium automotive plastic sheeting such as 3M™ Overspray Protective Sheeting goes through a chemical process called a corona treatment. This changes the surface chemistry of the plastic, helping paint adhere to it and preventing flaking. You can also tape directly to the plastic sheeting instead of using it in conjunction with masking paper, which saves time and material.

A: Traditionally, moldings and trim have been time consuming: to get a clean paint line, you must remove the trim before painting, clean it and reinstall it after the paint has cured. Instead, wherever applicable we recommend 3M™ Perforated Trim Masking Tape. This tape lets you mask trim and moldings without removing them, yet still attain fully concealed paint lines. The tape features a hard, rigid band along one edge. The band slips gently beneath trim and moldings and lifts them slightly from the body, allowing paint to flow under them. After paint has cured, simply remove the tape and let the trim drop back onto the body. The bands are available in several widths, helping ensure that they will hold the trim reliably. The masking tape is also perforated so you to tear it by hand, saving time.

A: Choosing and properly using the right masking products can go a long way toward eliminating issues related to quality and efficiency in the paint shop. But even the best masking tapes, masking paper and plastic sheeting will only be their most effective in a clean paint booth. Regular force-flashing with waterborne paints can upset the air flow in the booth, resulting in dirt and contaminants coming loose and falling on paint. We recommend 3M™ Dirt Trap Surface Protection Material, a nonwoven material with a light adhesive that applies to walls and floors and removes without leaving residue. This material traps even tiny particles of dirt and paint rather than simply collecting them, keeping them from spreading. This helps keep them out of the paint job, reducing time spent buffing later on. It also makes cleanup easier – you simply peel up the used material and replace it, with no daily maintenance. 3M offers Dirt Trap in white (slightly higher adhesive strength, great for walls) or gray, which hides footprints and is excellent for floors.