First a little education:
Before you become successful at eliminating paint swirls, or "mico mirring", you need to understand what goes into the paint finish. There are many differences in the paints you encounter. These variations determine the severity of swirls in paint and the process required to remove them.
The first step is to identify if the paint film is the OEM (original equipment manufacturer) finish applied by the auto
manufacturer, or has it been refinished by a body shop or other aftermarket painter.
OEM:
There are differences in the paints used by manufacturers, some use 1k (one component) urethanes on all models, while others use 1k on some models and 2k (two components) on others. The test in systems for today's 1k and 2k OEM clearcoats is usually a melamine/acrylic system. This is also referred to as polyurethane enamels. Regardless of components, both systems are subject to etching, scratching, chipping and swirls.
Paint Finishes:
Here is the data on paint finishes:
Finding information about the thickness of paint finishes from both vehicle manufacturers and paint suppliers can be tricky with the answers varying as much as the vehicles do. The base coat and clearcoat thickness can effect the way that you work on a particular vehicle. Below is what two of the major paint manufacturers had to say about paint finishes for the car manufacturers they supply. Then I will outline what the manufacturers actually use.
PPG:
Clearcoat 2 mils thick
Basecoat .6-1.5 mils thick depending on the color of the car.
Single stage 2-3 mils thick (primary process used for many red, white and black cars)
PPG does not recommend a particular type of wax to use on its paint finishes, although it does recommend not to wax within 60 days of the cars purchase date. PPG recommends following the washing procedures described in the owners manual for that particular car. PPG is the major paint supplier to virtually all of the major manufacturers including Ford, GM, Nissan, Chrysler and Toyota. Product may vary by plant and location
Dupont:
Clearcoat 1 - 1.5 mils thick
Basecoat and Clearcoat combined 3-4.5 mils thick
Single stage 3-3.5 mils thick.
Dupont recommends waiting 90 days before waxing a new vehicle and does not recommend a specific process or regime for caring for the finish.
The average clearcoat on a car is around 2 mils thick. It is highly recommend to follow the washing and care of the finish of the car in other articles we have written as these are tested for that finish.
Let's get a little more specific on finishes as it relates to Nissan's:
Total thickness: The maximum is 5-6 mils, but some finishes might be as low as 3.75 - 4.5 mils. These thickness ranges account for monocoats and base/clearcoats.
Pearls, or three coat process: 6-7 mils. This process includes a base, pearl and clearcoat.
A base rule to follow for Nissan vehicles is that each coat - including the e-coat, primer, base and clearcoat is 1.25 mils thick. Horizontal surfaces such as the hood and roof are a little thicker than the vertical surfaces including sides. Although Nissan advises when wet sanding, DO NOT remove more than .5 mils.
Nissan uses several paint manufacturers including Akzo-Nobel (Europe), BASF, Sherwin-Williams, DuPont, Herbert's, ICI (Europe), PPG. The only paint we use in our shop Spies Hecker. Only some cars made for Europe used it.
Now that we are educated a little, lets move forward to the problem of swirl marks. I bet you though I would never get there. At least I did not go through each manufacturer.
Refinished Paints:
Collision repair centers select the brand and quality of the refinish material based on many criteria such as recognition, service, industry preference and cost. We personally only use Spies Hecker as it is in our estimation the finest paint known. Most major paint companies offer their lines under more than one brand name. They have their premium line, constructed of better resin systems and pigments. The lower priced line is not chemically constructed the same way as the cost of raw materials dictates the final selling price. Part of the difference between a good shop and an excellent shop. These refinish materials are at the mercy of the painter - the collision repair center (body shop) must get the vehicles in and out quickly in order to make a sizable profit. Custom (concourse shops) charge more, use better products and processes and work on quality not quantity. The painter may also elect to add additional accelerator (hardener), change to a faster or slower dry thinner or increase the heat for curing in the booth. These are all tricks to increase volume.
Finally - THE MAJOR QUESTION AT HAND - "What causes swirl marks and how do I remove them, especially on dark cars?"
Swirl marks are caused by micro scratches on the finish, often caused by the use of bad hand or buffer techniques with the wrong type of polishing pad and/or wax polish. Hand applications appearing to leave swirl marks are often faulty washings, drying towels and/or techniques. Other causes are applications of an inferior wax and polish. The first step in removing swirl marks is having the proper equipment. Equipment should include tools to diagnose as well as perform the work.
The two most important diagnosis tools are a 30X lighted magnifier and a paint thickness gauge. If you had remembered in the earlier part of this article, paint thickness should not be removed beyond 3/10 mil or 1/1000th of an inch.
Chemicals:
Swirl mark removers fall in to categories - Eliminators and Fillers. Eliminators have lightabrasives that break down and will eliminate the swirls. The filler is just that, it only fills swirl marks. After a few car washes, the swirls will be visible again. Modern compounds utilize new families of abrasives whose particles continually break down as you buff. These products will not work satisfactorily if attempting to use them with a buffer above 1700 RPM. They will break down too quickly and go to a polishing size particle. If you have never used a buffer - do not attempt to try removal until you gain experience and stay with hand removal only. Some paint finishes will only gain it's best potential with hand techniques.
Polish or Light Scratch/Swirl Remover:
This category creates even more confusion. When choosing the correct product. This includes the pad and or cloth used. Some consider "glazes" a polish, but they simply create an optical illusion by covering up paint blemishes. They simply wash off and then leave the imperfections for all to see. Other glazes (advertised as show glazes) used the morning of the car show is gone by the end of the day. This is caused by UV rays and evaporation. Using this definition to select your polishes and/or swirl removers will save a great deal of confusion, time and provide clarity to you. Most professional detail chemical companies have a product that you can use as a polish or a swirl remover. Therefore, in an effort to reduce the never ending line of retail products, it is in your best interest to use a commercial grade product that is not multi-purpose. An example of a multi-purpose product is a polish/wax or cleaner/wax.
Equipment:
If you are not experienced with machines or new at detailing to a show level, ask for help before using this type of device on your car. You can burn the finish. Keep in mind that anytime you use a high speed buffer with a wool cutting pad and a compound you will put swirl in the paint finish. Swirls put in with a high speed buffer should be removed with a high speed buffer. This becomes a never ending battle. The use of an orbital buffer with good techniques is good BUT on fine paint finishes and on show quality cars nothing can beat the human touch.
Buffers: (If you must)
Variable speed buffers with speed control of 0-3000 RPMs are used in and by body shops for the finish cut, but if using for swirl mark removal, no more than 1500 RPMs should be used. Too much heat would be created and damage to the paint finish will result. Variable, dual action polishers and the old standard orbital wax machines are included.
Pads:
Never use a white wool four ply yarn cutting pad on any urethane finish newer than 1995. They are too aggressive and create heat very quickly. If you must use a white wool, keep the buffer speed to 1000 RPM and this is a maximum limit. You must also constantly check the paint finish surface temperature. It must be limited to 115 degrees F. Go above 115 degrees and you will create what is called by professional detailers (show quality) and industry representatives as "thermal stress". Thermal Stress are those long small cracks in the paint that looks like light scratches, but can not be removed by buffing. The Thermal Stress can also be caused by washing a car outside in the dead of winter with cold paint and utilizing hot water. This will not be evident until about a year later. And YES - even washing your car wrong will hurt the finish!
Buffing, if done incorrectly, can cause severe damage or ruin paint in a very short time. Use foam pads, as they are easier to use and there is less chance of harming the finish. If you are using a buffer or polisher - foam pads are the only way to go. Use a foam pad at 1000 RPMs. Foam pads should be kept clean ( for use either by hand or by machine). Contaminant build-up in the pads is a major cause of swirl marks. Take your time, apply the chemical to the pad first, keep the pad fairly flat to the surface. Let the polish burnish away imperfections and use a cross latch pattern. Again, I state the data above if you feel like Tim the tool man Taylor and have to use a machine. Personally - DO IT BY HAND.
By hand works well for swirl using a back and forth pattern - not circular. You can use a polish, paint clense or swirl remover to safely restore the finish. If you have deep swirls (not scratches) you will probably have to use a safe pure polish, followed by a paint clense and then a natural wax for a protective layer. If this process will not remove the swirls, take the car to a professional to determine if clearcoat restoration or repainting is required.
The HAND:
This brings us to using the hand. Most perfectionists on the show circuits enjoy working the finish by hand. Swirl marks can be removed using correct techniques and quality commercial products. As stated above, the chemicals used should be applicable to both machine and hand usage. The hand technique should require no real pressure if you are using the product correctly. Let the product do the work. To much pressure and you add to your problems.
Always as with waxing, use a back and forth method and work in small areas at a time on the car. By trying to go in circular motions as does the machines, you are more likely putting swirls in the finish. After all is complete, apply your wax as this will enhance and protect your work and more importantly the finish of the car. Two light coats of a non-drying wax is recommended.
In short -----------for the best results follow these steps:
Decontaminate / neutralize the car by washing (Clay after washing may be required if the surface feels rough).
Know the type finish you are working on. It is important to know if the finish is lacquer, clearcoat or another type of paint. Likewise it is best to know the thickness. You must leave a durable thickness in the paint for protection. The masses will not have a gauge - get one or go to a real professional body shop and ask for a reading.
Select quality products and follow the directions. I do not recommend retail products or gimmick silicone products.
Do not use aggressive pads or products on clearcoat and never get them hotter than 115 degrees F.
Always take you time in the polishing and waxing process.
Repair the swirls - do not fill them. Washing will remove glazes and fillers and allow the swirls to re-appear.
If a detailer skips the polishing step after buffing and immediately applies wax over the swirls it will not remove the swirls.
Inspect the work in good light to ensure all the swirls are removed. Insufficient light adds a lot of labor.
So now you have it - the complete story on swirl marks and the removal thereof. Get involved so you can become more knowledgeable when purchasing products.
Copyright 1999 Angela Brown - Paul Gasparola
Avalon Ent - Racing Division
