DuPont Surface Cleaners

In the movie, Karate Kid, do you remember the instruction that Mr. Miyagi gives Daniel on waxing a car?Wax on, right hand. Wax off, left hand. Wax on, wax off.  Don’t forget…very important.”

In the vinyl graphics business, the right hand, left hand technique is the traditional way decal installers are taught to clean with a solvent surface cleaner. In one hand, saturate a clean rag in pail of solvent. In the other hand, hold a clean dry rag.  Wet the substrate with the wet rag. Then use the dry rag to wipe the surface clean,before the solvent can evaporate.

What’s wrong with the one handed approach of just mopping the surface with a wet rag of solvent? The thinking is that using this technique all you do in move any of the surface contaminant from one area on the substrate to another. The end result is that the contaminant is still there! It’s just in a different place on the vehicle.

Believe it or not, some communities, such a San Francisco, have banned wiping down a surface with a solvent saturated rag whether you use one hand or two. The reasoning behind the regulation is that when you saturate a  rag with solvent too much evaporates into the air. So what’s a decal applicator going to do?

The approved method is to use a spray bottle to squirt the solvent onto the surface. After spraying the surface with solvent, use a clean, dry rag to dry it. As silly as you may think this regulation is, this alternate cleaning method is effective…and in some municipalities, it’s the law.

Whether you drench the surface with solvent or spray it on, it is very important that you use a clean rag, paper toweling or disposable rag to dry the surface before the solvent evaporates.

Which Cleaners are Recommended?

When installers clean a car or van prior to a vehicle wrap, many will use a “wax and grease remover” in their prep process.  Not all of these “wax and grease removers” are the same.  In fact, the strength of these solvent cleaners can vary greatly. Some are very strong and can damage some paint systems. That’s why you need to know the potency of the solvent that you are using.  And before you use it, test the solvent in an inconspicuous spot on the vehicle so you don’t damage the paint job. One of my mantras is “test, don’t guess”.

Another differentiating property of a solvent is the speed at which it evaporates. Some types of solvent cleaners flash off of the surface very quickly. Other evaporate at a much slower rate. For prepping a vehicle surface prior to graphics application, you typically don’t want either one that flashes off too fast or too slowly.

My personal preference in a brand of solvent is DuPont. They make many different solvents for different applications.

DuPont’s Prep-Sol® 3919S is an essential cleaner for truck graphics installers. It is a strong, fast-drying solvent that will clean tough contaminants, such as tar and grease.  Because this is a strong solvent, you need to be careful when using this solvent on some paint jobs, such as enamels, or it could damage the surface.

DuPont Kwik Clean 3949S™ is a milder waterborne alternative for cleaning repainted vehicles prior to graphics application. It works well to remove dirt, sap, splatter bug remains and road film.

In applying vinyl graphics to fiberglass many installers will prep the surface with  DuPont’s 3812S Reducerto remove the waxy release coating used in the manufacturing of molded products.  Without cleaning off the release agent is virtually impossible to adhere vinyl graphics to this surface.

Before using any solvent cleaner, first wash the surface with a mild detergent and water. After using the solvent cleaner and immediately before you begin your application, wipe the surface down with Isopropyl Alcohol (IPA). This cleaning procedure is described in detail in my article 3-StepPrep for Vehicle Graphics.


Chuck Bules of Arlon  recommends periodically checking your rag, whenever you are solvent cleaning any painted surface, especially an aftermarket paint job, to make sure that you are not removing paint as well as the dirt.

Before using any solvent cleaner, read the technical data sheet and the MSDS that pertains to that chemical. Use of a solvent cleaner may require the use of a properly-fitting air-purifying  respirator, latex gloves and eye protection.
My final bit of advice is to work in a well-ventilated area.

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