Extreme care, attention to detail needed to achieve quality control in the paint shop
True quality control in the paint shop is a constant requirement. If a paint job is not checked and re-checked at every point, the consequences can be very costly in time and materials.
Quality guru W. Edwards Deming stressed years ago that quality and continuous improvement were the only way to assure continued success in manufacturing. He suggested building quality into products through statistical methods and preventing defects instead of trying to detect them. Worldwide manufacturing has since adopted his continuous improvement methods as its standard, with quality, efficiency and profit vastly improving as a result.The collision repair industry has looked to manufacturing for methods to improve its operations. By preventing defects as its standard, it too will see improvements in production and quality, which will assure increased profits as well. So how does a shop go about developing a zero-defect policy?
STEP 1: Develop a SOP. It takes time to develop and revise a standard operating procedure (SOP), and it takes time to follow it. How can this help improve productivity? Once it is developed and in place, it helps keep repair procedures consistent. It also helps with supply purchasing. By standardizing a repair process, a simple standard supply list can be developed and maintained.
The SOP not only indicates the repair process, it also outlines quality verification at specific intervals, such as arrival, color retrieval, cleaning, initial prep, final prep, masking, booth prep, sealing, basecoat, clearcoat, detailing and final inspection. While you might choose to develop an SOP with different points, having a written document will help avoid costly mistakes.
Consider these SOP quality assurance points:
STEP 2: Upon arrival. The painter or paint team must inspect the vehicle as it arrives in the paint shop, making certain that all the work outlined in the work order (repair blueprint) has been completed to the shop's quality standard (see Fig. 2). The paint team should make a repair plan, which confirms the vehicle's position in the paint order, checks for needed supplies and notes any special requests, such as strips that may need to be ordered.STEP 4: Cleaning. Painters often skip this step because they think the vehicle already has been cleaned. But the cleaner a vehicle is as it is being prepared for paint, the less likely it will be to have defects. The degree of cleanliness required in the paint shop is much greater than what's required in the body shop. Something as simple as a helper eating at break and not washing his or her hands before masking a vehicle can cause contamination.
The entire vehicle should be soap and water washed (see Fig. 4) to remove water-soluble contaminants. Then the area to be refinished and the adjacent panels should be cleaned with a wax and grease remover to remove contaminants that are not water soluble. If sanding is begun before a vehicle is completely cleaned, it may drive the contaminants into the area being repaired instead of removing them.After the vehicle is dried and inspected, it can be placed in front of the spray booth for masking.
STEP 7: Masking. Masking in the paint booth, can lead to dirt contamination. Though "bagging" the car must be done in the booth, all the rest of the masking should be done outside the booth, to eliminate as much dirt in the booth as possible (see Fig. 8).Mask from the inside out – that is, open the doors, hatch, or hood in the area to be masked, and apply your mask in that area first. Then the openings can be closed and the paint area outlined with tape. A cut down used body filler shredder is an excellent tool to use to assure that the tape is pressed tight to those hard-to-reach areas. While applying tape, technicians should be constantly inspecting the vehicle for any possible defect as they proceed. The taped area can now have a small (12-inch) paper placed around the taped area, preparing it for bagging.
STEP 8: Booth prep. The cleaner the booth, the cleaner the final paint job will be (see Fig. 9). The booth should now be started, and all temperatures should be set correctly. It should be balanced to a slight positive air flow. If the booth cannot be balanced, it is likely that the filters are in need of changing. This should be done before the vehicle is painted. With the booth turned on, the booth interior should be blown off. Make sure the floor is clean and all needed tools are inside the booth, ready for use. Then the car and the parts that need to be painted are placed in the booth, the outer doors are closed, and all subsequent entries into the booth should be through the pedestrian door. Once the vehicle is in the booth and bagged, the masking should be inspected for loose areas, and if found they should be repaired before proceeding.There is one last opportunity to inspect the vehicle before clearcoating. If any imperfections are found, they can be nib-sanded out. Then the area is re-sprayed with basecoat, preparing it for clearcoating.
If each step in this process is followed correctly, it will mean that the ones that come after each become another inspection, with little or no corrective action needed. Polishing can be kept to a minimum and cycle time will be reduced. By eliminating defects early, when they can be corrected more easily, final repair can be virtually eliminated. By finding and eliminating potential defects early in the paint shop, you "pay forward" in cycle time and profit.