The automotive repair industry relies heavily upon the use of test cards. Before the first coat of a new colour is sprayed on a new car, paint companies have prepared and evaluated test cards to ensure that the new formula will perform properly. The words “test cards” should remind us that we need to do an evaluation before moving on to the real task at hand.
Aftermarket retouch products are expected to perform as well as the original heat-cured coatings. During the past few years, paint suppliers have seen a move 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 retouch products to have consistently better performance than previous products.
At the retouch 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 colour retention in some of the harshest environments possible. All paint companies are required to subject their test panels to a barrage of quality requirements. Those results are then scrutinised by many sets of eyes before the paint system receives final approval.
Test cards are needed when you’ve identified a problem colour or when experience tells you matching could be a problem. Test cards are a routine part of any collision repair process. Developing test cards 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.
Spray the test card with a base-coat and a clear coat and compare it against the original paint work. Test spraying the test card with your base-coat colour is important, it helps you determine if the colour is going to match before spraying it onto the vehicle. It also gives you practice for learning the spray pattern of your paint spray can, so you’ll get a better finish without runs or drips.
Due to a vehicle’s age, and how it has been looked after; garaged, etc. getting an exact match isn’t always possible, which is why you aim for a “close” match.
Make sure you write the necessary details on the back of your spray test cards such as vehicle make and model, for future reference. Be sure to save your spray test cards to create your own personal colour reference library. They will help you in the future save time and money and avoid any unnecessary waste of paint.