When your car was brand new, it rolled off of the dealership lot looking smooth and shiny. Today the paint seems a bit drab and dull. There are a number of reasons for dull paint on a car – contamination, oxidation, scratches, and more. The remedy is often the same: buffing the paint.
Depending on who you ask or what website you reference, you will get a different definition of the words buffing and polishing. But buffing (or polishing) simply refers to making the surface of your paint smooth and shiny by rubbing it. Buffing can be done by hand or with a machine. Buffing can be aggressive or it can be gentle. Of course, when done correctly, buffing can make your car look like new again; if not, it can destroy your paint and damage the body of your car.
What causes dull paint?
What causes dull paint in the first place? There are three basic categories that answer that question: contamination, oxidation, and scratches.
Contamination comes in many forms. Environmental compounds from bird droppings, bug residue, tree sap, acid rain, and good ole fashioned dirt and debris can cling to the surface of your car and create a dull appearance. Sometimes the contaminants can be simply washed off to reveal the shiny paint underneath, perhaps with the use of chemical cleaners.
Other times, contaminants need to be removed with a clay bar, designed to pull away substances that cling tightly to the surface or become embedded. Rail dust, overspray, and hard water staining are examples of contamination that might be removed with a clay bar treatment.
Sometimes, contaminants actually alter the surface of the paint. For example, acid rain and bird droppings can etch the paint if left untreated. When this happens, the paint must be repaired by buffing. The surface might even need to be sanded first.
Oxidation appears as a chalky residue on the surface of your car. It can give the paint a dusty or milky look. Sometimes the color is faded as well. Oxidation occurs as a result of your car’s paint being exposed to the elements and it doesn’t come off in a car wash.
Modern automotive finishes are more resistant to oxidation than those of the past. Older vehicles had a tendency to fade significantly from oxidation; a red car could turn pink, a black one to a dull grey. Some of the damage can be from the ultraviolet rays of the sun breaking down the paint’s pigment, but oxidation is also a culprit. Oxidation can appear on the entire surface, or it can show up in patches. It is most prevalent on the top surfaces – the roof, hood, and trunk lid – since the ultraviolet rays exacerbate the condition.
Scratches happen whenever a sharp object rubs against a panel on your car. Much to his father’s chagrin, a child recently memorialized a family vacation with a mural carved in stone on the side of the family car. A key, a rock, or the handlebars on a child’s bicycle can all cause scratches in the paint.
But those are not the type of scratches that cause the paint to become dull. Rather, dull paint is caused by scratches that are microscopic in size. These can occur by years of wind and rain scouring the surface with sand and dirt. They can happen by frequent washings in an old-school nylon brush car wash (as opposed to a modern soft-touch automatic car wash), or by improper washing by hand at home. Together, these countless barely-visible marks combine to diffuse the light enough to make your paint look dull, and give contaminants a grip so they cling tightly and add to the dullness.
A car that has been sitting still for some time, whether out in the sun or under a tree, is a likely victim of dull paint.
How is dull paint corrected?
Whether your dull paint is caused by contaminants, oxidation, or other environmental damage, or by micro-scratches, the course of treatment is similar.
For a professional detailer, the first order of business is always a thorough cleaning. The paint cannot be corrected when it is dirty; additional damage would result when dirt and other contaminants are smeared across the surface. Then a clay bar is used to remove any stubborn or embedded contaminants. With the vehicle completely clean, an assessment must be made to determine the cause of the dull paint and the corrective action needed.
In some cases, when oxidation is present or when micro-scratches dull the paint, the surface must be buffed back to a shine. Buffing is a multi-step process with varying levels of intensity or aggressiveness. Unlike the application of a wax or sealant, paint correction involves tooling or reworking the surface of the paint. It alters the finish.
Here is a list of procedures that a technician might need to employ to correct a dull paint finish:
Hand buffing
Hand buffing is performed without the use of a machine. Rubbing compound is a liquid abrasive that mechanically removes contaminants and smooths a surface, similar to sandpaper only finer and less aggressive. Buffing with a hand compound brings back gloss to the paint, and when done properly, is generally the least intrusive method of paint correction beyond a clay bar. Hand compound is used to treat small spots rather than large panels or a whole vehicle.
Machine polishing.
Areas that are too large or too damaged for hand buffing are treated with a machine buffer or polisher. Machine polishing can be fairly gentle on the surface, or it can be quite aggressive, depending on the type of machine used and the buffing pad attached to it.
A high-speed rotary polisher, either pneumatic or electric, is the quickest and most aggressive method of restoring gloss to your paint. It can be used with a wool pad (more aggressive) or a foam pad (less aggressive) along with a micro-fine rubbing compound. Gone are the days of coarse-grit rubbing compounds; instead, a modern formula is designed to break down to smaller and smaller particles as it is used.
Dual-action polishers are less aggressive than high-speed rotary models. They are not able to machine the paint as deeply, but they leave behind a more consistent surface with fewer swirl marks than their rotary cousins. Though newer on the market and often more expensive, dual-action polishers have fast become a favorite among detail technicians (of course, both types have their uses).
An orbital buffer is a device more suited to application of a coating than machining of a surface. It is gentle and covers a lot of territories, but is not used to remove oxidation or otherwise correct dull paint.
Sanding
Sometimes compound alone is not enough to correct the imperfections in a paint finish. Sometimes the surface needs to be leveled with a more aggressive tool: sandpaper. Ultra-fine and micro-fine sandpaper ranging from 1000 grit to 3000 grit and beyond can be used in stages to sand out light scratches in the clearcoat or remove contaminants that clay and compound will not. Once sanded, a painted surface must be buffed with compound (usually by machine) in order to remove the sand scratches.
Glazing
Often referred to as “swirl removing”, this stage is intended to diminish the swirls left behind by coarse wool buffing pads and rubbing compound. A panel might need to be sanded to remove a scratch (or lots of them). Then it is buffed with compound to remove the sand scratches. Then it is glazed to remove the swirls left behind by the buffing process. This stage is usually done by machine with a gentle foam pad and a non-abrasive glaze or swirl remover and leaves behind a clear and glossy surface.
Waxing.
Up to this point, nothing has been added to the paint finish. Actually, material has been removed in each of the preceding stages. Once the paint is smooth and glossy, it is time to protect and keep it that way. That is where wax or polymer sealant (or both) comes in. Waxes and sealants provide a waterproof, air-tight barrier that sheds water and prevents contaminants from adhering to your paint. They also protect the paint from UV rays and provide a sacrificial barrier (in the case of wax) that will not allow caustic environmental compounds from etching the surface.
The downside of doing it yourself
A quick search on the internet will bring up all sorts of sites that describe “how to” buff or polish your car. Certainly, if your paint is looking dull, it could probably do with a good buffing. But should you do it yourself?
Well, people all over the country have been practicing social distancing while under stay-at-home orders during the COVID-19 pandemic. During that time, many have not been able to visit a barbershop or salon to get a haircut. While there may be some highly-skilled individuals who can look in the mirror and shape their own hair, most people would prefer not to wreak havoc on their heads and make matters worse but are letting it grow out until they can visit a professional.
Same goes for the paint on your car. It makes sense to have your car professionally detailed. Many auto owners have attempted to buff out imperfections in the paint on their vehicles only to find that their abusive treatment left more damage, or at least did not correct the initial problem. Without the proper tools and the experience that says how and when to use those tools, you can cause quite a bit of destruction.
The paint on a modern automobile is made up of a thin opaque color coat (basecoat), often infused with metallic or mica fragments for effect, covered with layers of hard, clear acrylic (the clearcoat). This basecoat/clearcoat system has been standard on vehicles for decades. Prior to that, many cars and trucks were painted with single-stage lacquers or enamels. If your car was made from the nineties onward, it likely has a basecoat/clearcoat finish; if it is older than that, it probably has single-stage paint.
Single-stage lacquer and enamel both present problems for someone trying to buff out any irregularities. First of all, without the UV protection of a clear coat layer, single-stage paints are highly susceptible to the elements and tend to fade faster. They are also less abrasion-resistant than modern finishes. Single-stage paint has pigment all the way through, like house paint. What you see is the top layer of pigment. When you sand or buff the surface, you are removing some of the pigment. Remove too much and you will either create an uneven finish because you have gone through to the next layer, or you will see through the paint altogether to the primer underneath. And single-stage paints are easy to sand and buff through.
Fortunately, modern acrylic basecoat/clearcoat systems are far more durable than their predecessors. But that does not mean they are foolproof. Because the clear coat surface is so hard, it is more difficult to manipulate. For instance, a hardened clear coat makes it more difficult to remove swirl marks left behind by buffing with compound. Hard clear coat might make it more difficult to “burn through” than single-stage paint, but it also means that the level of work performed must be closely matched to the amount of correction needed. The tools, techniques, and materials must be fine-tuned to correct the problem without causing more damage.
What’s more, if you remove too much clear coat – by sanding or by buffing – you will significantly diminish its protective qualities, from abrasion, from oxidation, and from the sun. And even though clearcoat is durable, it is still not immune to burn-through (removing too much material or melting) if a polisher is used improperly, especially on the edges and ridges of panels. If the clearcoat melts (burns) or gets too thin (especially if you remove the basecoat underneath), the panel will need to be repainted – at a cost of hundreds of dollars per panel.
Without the proper tools and training, you can wreak havoc on the finish and cause more harm than good. A professional detailer, on the other hand, knows how to evaluate your paint and determine the correct course of action to restore it. With the right skills and the right materials, a technician can correct the problem of dull paint and restore the shine on your car.
As part of spring cleaning for your car, consider an evaluation at a detail shop to determine whether your vehicle needs only a thorough wash and a coat of wax or something more comprehensive, like complete car detailing and buffing to restore dull paint.
Columbia Auto Care & Car Wash | Author: Mike Ales | Copyright
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