The requirements of automotive masking have not changed since the first piece of tape and paper were applied: Cover and protect items or areas that are not supposed to be coated. What has made tremendous strides and changes are the quality and types of products we use today to provide protection.

The decision of whether to remove or mask continue to vary greatly between shops and people. Common questions asked are: "Why mask if I can take it off? versus: " Why take it off if I can mask?"

The decisions include the following: What type of tape? Which paper? Will it bleed? How far should I cover and protect? When should I remove it? These questions can become confusing or complex, but this article should help clarify your concerns.

Masking paper has also seen many changes. Rarely does one see newsprint being used. Papers today have many of the characteristics of the tape: Bendability, resistance to solvent products, they waterproof, have smooth sides, easy tear and varying widths.

The economy paper on the left not only tears unevenly, but exposes fibers. Using quality paper will save time in many ways. Note the cleaner tear edges as the quality improves. Masking paper is often chosen by cost factor only. Consider also, the ease of unmasking and or overall quality of the repair. Repair costs of one refinish contaminated with paper fibers will more than offset any savings you make using inexpensive paper.

Plastic sheet protection was introduced almost 20 years ago and has since become a universal method for protecting large areas. This inexpensive product provides ease of application, easy removal and assists in eliminating dust and dirt contamination from the painted surface.

Specialty items include: Foam tape for sealing door jambs, pre-scored pullout tape for painting pin stripes; heat reflective paper that helps prevent distortion to elastomeric parts; and pre-taped rolls of paper or plastic sheet for ease of masking.

Product Selection Your choice of products may be largely based on personal preference; however, application requirements will dictate more of the technical reasons for selection.

Masking tapes may have unique characteristics and even provide additional benefits. Likewise, improper selection of a tape can cause problems. Let's look at the basic varieties of masking tape.

Standard automotive masking tape is paper backed and "creped." This bunching of the backing allows the tape to be stretched or bent to allow turning. Glues are generally adequate to stick to any prepared surface. New tapes have glue that allows application to sensitive basecoats or multi-application colors without causing glue transfer or imprinting. Used with ultra-thin basecoat finishes seeping into these crepe folds can occur and result in a fuzzy edge. Standard widths range from 1/8-in to 3 in. Thickness averages 6 mils to 8 mils (6/1000 in. to 8/1000-in.).

Application of a back folded piece of paper prevents color coat overspray onto the areas where clear will be applied.

Vinyl back plastic tape is also widely used. This tape gives excellent adhesion in critical areas, in addition to sharp fine edges.

Other items, tools and supplies needed to conduct quality masking include the following:

Paper or plastic rolls or sheets provide overspray protection from small areas to entire vehicles.

Masking paper is manufactured from wood pulp like any other paper product. Wood fibers and glue are spread out on a moving belt, dried and rolled up. Automotive grade masking paper, however, has some unique differences. The fiber length is shorter and prevents it from breaking loose and contaminating the finish. Glues in the paper are designed to be resistant to water, solvent or both. The processing polishes the paper to a smooth, slick surface that resists adhesion of floating dust contaminates.

Masking paper is often chosen by cost factor only, with no thought given to the importance of dust control, bleeding protection, ease of unmasking, or overall quality of the repair. Repair costs of one refinish contaminated with paper fibers will more than offset any savings you make using inexpensive paper.

Technicians who wet sand during the repair process should select a paper that will not break down from the water exposure. The paper is usually available in widths of 3 in. to 36 in.

Plastic sheet masking has become universal in most facilities. Rolls in widths of 9 ft. to 16 ft. and up to 500 ft. provide material that is easily applied to the vehicle. This sheeting allows large areas to be covered in a single process with no joints to allow overspray leakage. The plastic is usually tucked behind masking paper and sealed with tape. The nature of the plastic helps attract passing dust particles, which prevents contamination of the paint finish.

Over-masking or under-masking of the reveal molding is prevented by use of cording.

Foam cord or tape is a small foam, usually 1/2 in. in diameter, used in door jambs, trunk openings and hood seams. This foam is lightly glued on one side, is very soft, and flexible. Placing the cord in openings prevents a hard edge of paint, and also prevents overspray in the jambs or openings.

Some technicians will use this product to "reverse mask" on sharp edges, limiting the total area needing to be refinished.

Cording or lifting tape is used to lift up the edge of rubber reveal moldings. By lifting the molding, paint material is applied to the surface under the molding. This step prevents peel-back of the finish, and over or under masking of the molding.

Hints and Tips for a Quality Finish Masking is only part of the process that provides a clean and defect-free finish. Remember-masking will not prevent all dirt, dust or other contaminates from the finish. Most dirt is taken into the paint booth on the vehicle or the painter, is already in the spray booth, or leaks around the door seams of the booth structure.

• Clean the spray booth on a regular basis, not just when it looks dirty. Monitor the draft gauge that indicates filter restriction and needed filter replacement.
• Conduct major blowing and wiping of the vehicle outside the spray booth. Only do final wax and grease removal and tack wiping in the spray booth.
• Attach a ground strap to the body structure of the vehicle. This step will remove static buildup caused by sanding, wiping and blowing.
• Only use quality masking supplies. Economy tapes from the hardware store won't meet your needs.
• Plan your masking for ease of unmasking. Remove tape along a clearcoat edge so it can melt down and should not require unmasking other parts or areas first. One easy process is to mask using crepe tape and hold back about 1/4 in., then apply the plastic style tape at the edge of the repair and overlap onto the crepe tape. Upon completing the last clearcoat, removal of only the plastic tape is required for melt down of the edge.
• Apply long strips of tape and paper. Many short stubs of tape will allow leakage or result in over-masking.
• If after initial masking a substantial amount of sanding takes place or wet sanding is conducted, it is wise to unmask, clean and re-mask.
• During final wiping with a tack rag, also wipe all masked areas.
• Tape should not be allowed to remain on the surface more than three or four days.
• Never allow tape to remain on the surface if the vehicle is left outside in rain or direct sunlight.
• Carefully remove masking once the finish is dry to the touch.
• Follow the equipment manufacturers' instructions on allowable time for removing masking when using high temperature or infrared force-drying.