Editor's note: This article was originally published March 2006, but the information is still accurate today.
The automotive refinish industry relies heavily upon the use of test panels. Before the first coat of a new color is sprayed on a new car, paint companies have prepared and evaluated test panels to ensure that the new formula will perform properly. The words “test panels” should remind us that we need to do an evaluation before moving on to the real task at hand. With that in mind, we hope to demonstrate the reasons for test panels in a collision repair facility and provide a few helpful suggestions about how to prepare them.
As you know, air-dried aftermarket refinish products are expected to perform as well as the original heat-cured OEM coatings. During the past few years, paint suppliers have seen a move at the OEM level to raise the bar with regard to exposure durability and chemical resistance. This all started a few years ago when acid rain damage became an issue and was followed by the need for refinish products to have consistently better performance than previous products.
At the refinish level, increased product performance and/or durability can, in most cases, mean total reformulation of the product or revision of the existing formula. In the reformulation process, paint manufacturers may be forced to use another special additive or develop a new or revised resin base in order to gain the best possible product performance. Air-dried products are rigorously tested for humidity and chip resistance, salt spray, chemical resistance, long-term durability and color retention in some of the harshest environments possible. All paint companies are required to subject their test panels to a barrage of OEM quality requirements. Those results are then scrutinized by many sets of eyes before the paint system receives final approval.
Now that we’ve discussed the need for paint companies and OEM suppliers to use data obtained from the evaluation of test panels, let’s talk about why test panels mean so much at the collision repair level. Ultimately, the most important factor at a collision repair shop is quality of work. We all know that the word quality is defined by many factors. For the customer, it starts with the collision center receptionist, moves to the estimator, goes on to the scheduling and processing of the repair, and then to the final inspection prior to receiving the keys to the vehicle. Each of us has different definitions of what’s important throughout each step of the repair process. As a past paint formulator myself, I’m looking for pre-accident condition. I want the bodywork, flow and/or smoothness of the paint, final gloss and color of the refinish repair to match the original finish on the rest of my vehicle. These are the points that define a successful repair for me. I take for granted that it will be done on the date promised and that I’ll be notified if it’s going to be delayed.
If you’ve attended a training class presented by one of the refinish paint manufacturers or I-CAR, you’re aware that although color match is created equal, not all spray-outs of the paint are. Paint companies are provided with OEM color standards from the car manufacturers as well as parameters and tolerances for controlling the final color. Through the use of test panels, the color is then evaluated to ensure that the pigmentation used to obtain the match is durable and will not change when exposed to the sun’s ultraviolet rays.
Test panels are normally needed when you’ve identified a problem color or when experience tells you matching could be a problem. However, when I spoke to Ralph Defibaugh, owner of Spa Body Works in Ballston Spa, N.Y., he stated that, “Test panels are a routine part of my collision repair process and nothing goes into the booth without one.” He has equipped his estimators with color variance decks, and the color chips are compared to the vehicle in sunlight before it comes into the shop. His estimators also use the variance deck as a sales tool with the customer to demonstrate that five or six colors are sometimes available for the same color code. Defibaugh further stated that he has an employee working in the parts department who has been trained to check the color and spray out test panels in an effort to increase the shop’s productivity.
As we’ve discussed, refinish paint is matched to an OEM standard panel, but if there is any variation in the color at the manufacturer or if the color has shifted due to harsh atmospheric exposure, there will be obstacles to overcome. Most solid colors are easily matched. However, the use of a test panel will be required if you see variation in color chips or more than one formula alternate is offered. The ideal time to use the test panel process is when you are applying refinish products containing metallic or pearl elements. At the present time, less than 5 percent of OEM colors are solids and the remainder is either metallic or pearl finishes.
Developing test panels is not rocket science, and the following steps can be easily accomplished with the car in the prep stages, thus freeing up precious booth time. The easiest way to develop test panels in your facility is to start by gathering the tools that are readily available. First, decide which substrate to use. Many paint distributors offer
4-in. by 12-in. treated steel sheets that can be used as a substrate for the test panels. Some collision centers cut small sections out of wrecked hoods or deck lids and use them for test panels. Most jobbers and paint suppliers carry 2-in. square black and white hiding stickers that can be affixed to the metal panels and are used to measure color coverage—commonly referred to as color hiding.
The most popular, least expensive and easiest to store alternative are 4-in. by 6-in. hiding charts with black and white lines. If you need to repair a contoured area such as a fender or quarter panel, these paper cards can easily be bent around the blending area for better color comparison. You must ensure that the paper panels used are non-absorbent to prevent solvent soak-in, which will modify the final appearance of the color.
Once you’ve selected a substrate, apply the desired sealer and then the color coat following label instructions. You may choose to eliminate a primer or sealer step in some cases, but please pay particular attention to the paint manufacturer’s instructions as the color of the sealer may have been formulated to affect the final color of the base or topcoat system. If this is the case, “sealer required” information is usually given as part of the paint formula or is available from the paint manufacturer. You should have some color representative panel or color card chip for comparison because this is the time to compare the manufacturer’s paint chip or panel with your test card to ensure you can match the color in the paint booth. This important step in the test panel process helps the painter dial in the number of coats of primer, sealer and color needed to provide total hiding. Simply stated, if you’ve sprayed on two coats of base or topcoat color and you’ve achieved hiding, you can stop. If you can still distinguish the black and white areas of the hiding sticker, you need another coat.
Never use more than the amount of paint required and always follow the paint manufacturer’s instructions with regard to dry time between coats in order to achieve the best product performance from each coat of color. If the finish on the vehicle is a basecoat/clearcoat color, it must be clearcoated before the final color evaluation can be completed. It is also important to remember that air pressure at the gun, paint reduction, spray gun setup and painter technique all play a part in the refinish process. Because of these variables, the same color can be sprayed by two different technicians with different results.
Finally, when you’ve done all the comparisons and feel satisfied that you’ve captured the color you want, you’ll need to log the details on the backside of the panel. Take the time to write down the spray gun settings used, reduction ratios, number of coats, sealer used (if it affected the final color), color code, formula, etc., and store the test panel in a safe location. Some collision repair centers have developed their own color library of test panels bound with a key ring thus enabling them to be removed one at a time when needed.
The process for developing test panels and using them in your facility may take a few minutes of additional time, but the payoff will be substantial for all involved parties including the collision repair shop, insurance company and the owner of the vehicle. Successful, quality-minded collision repair centers have been making test panels for years. The real goal for any repair center is to save time, effort and money in the repair process by eliminating re-do’s in the paint booth due to unacceptable color match and/or questionable appearance.
