Decals and the Car Wash

You put a decal on your car to see it every day, which means it rides through every wash the car gets. The film makers who publish care bulletins for their vinyl agree on the basics. Water and soap are fine. Edges are the weak point. And some of the equipment at a car wash is built in a way that finds those edges.

3M and Avery Dennison write the most detailed care advice, and ORAFOL adds a note about the first day. Each bulletin is written for its maker's own films, so wherever a figure belongs to one maker, you will see whose it is.

Wait before the first wash

Avery Dennison's care bulletins, the European one and the Asia Pacific one, both say its films should not be cleaned or washed within the first 48 hours after application. 3M's maintenance bulletin gives no waiting period at all, and ORAFOL's notes ask only that you avoid a sharp drop in temperature in the first 24 hours.

So the 48 hours is one maker's figure for its own films, not a law of vinyl. It is also the most cautious figure any of the three prints, and two days is an easy wait. Put the decal on after a wash rather than just before one, and the schedule takes care of itself.

A decal applied in cold weather deserves more patience still. 3M notes that a graphic applied near its minimum application temperature and then put straight into service in winter weather may not develop its full adhesion. Two days indoors, or at least two days without a trip through the wash, is the cautious choice.

Brushes are the problem

On automatic washes with spinning brushes, both makers are direct. 3M says brushes can catch a loose edge of a graphic and cause further damage, and that brushes can dull the finish. Avery Dennison does not recommend automatic brush car washes at all, because the brush will often catch the edges of the graphic.

A die-cut decal is mostly edges. There is no clear border to protect the outline, so every letter, every gap in a script and every point of a shape is an edge of its own. A design with many fine parts, like the narrow lowercase letters of I Run Like a Girl, has far more of them than the AK Alaska Euro Oval, whose outside is one smooth ring.

3M raises one more point about automatic washes, in a separate bulletin on preparing surfaces: the chemicals used in some automated vehicle washing equipment may interfere with adhesion. None of the documents we read rates a touch-free wash, so we cannot tell you whether one is gentle on a decal. Hand washing is the method every bulletin describes in detail.

At the pressure wand

A self-serve bay or your own pressure washer is allowed, within limits. In the words of 3M, power washing is allowed, but too much pressure can push water under the edge of a graphic and a heavy hand can damage it. Here is what the makers print.

Conversions marked "about" are ours.

The distance figures disagree, and the European Avery Dennison bulletin asks for the most room. Standing 75 cm (30 in) back meets all three. Keep the wand square to the glass, too. Avery Dennison explains that a sharp angle, or an intense jet from a narrow nozzle, can lift an edge, curl it or start the film coming away, and 3M asks for a spray pattern at least 40 degrees wide.

If the bay has a hot setting, keep the water at 60°C (about 140°F) or below, the lowest of the printed maximums. Choose the widest fan tip the wand offers, since both makers ask for a wide spray rather than a narrow, intense jet.

Washing by hand

The gentlest wash in the bulletins is the one you do yourself. Avery Dennison suggests rinsing loose grit away first with a low-pressure hose, because loose particles can scratch the surface when a brush or sponge drags them along. Then use a mild liquid detergent and water with a soft brush, a rag or a sponge, and, as 3M puts it, avoid unnecessary scrubbing.

Choose a soap without added waxes or polishes, which is how Avery Dennison describes the detergent it wants on its films. Rinse with clean water. 3M lets the graphic dry on its own, and Avery Dennison suggests dabbing it with a chamois or a soft, non-abrasive towel, careful not to lift the edges. Dab, do not rub.

What stays off the decal

Strong solvents and abrasive cleaners are out. Avery Dennison says both may damage a decal, and it specifically asks that hard solvents such as isopropyl alcohol stay off the surface of its film once the film is applied. That can sound odd, because alcohol is exactly what you used to clean the glass before the decal went on. Wax goes on the paint around the decal and never over it.

3M's test for any cleaner is that it should be wet, non-abrasive, without strong solvents, and between pH 3 and 11. Avery Dennison also rules out high-pressure steam cleaning, because the heat can interfere with how the film holds to the surface.

Wax is the other thing to keep in mind. Avery Dennison wants a detergent without added waxes or polishes on its films, and 3M asks that no wax, polish, paint or clear coat go over its matte films. If you wax the car, work around the decal rather than across it.

After the wash

Take one slow walk around the car. 3M asks that after washing you look over every graphic for edge lifting, and repair, remove or replace any that has been damaged. A corner that has just started to lift is easier to deal with that day than after three more trips through the wash.

A fresh wash is also the wrong moment to put a new decal on. 3M's surface bulletin warns that the chemicals in some automated washing equipment may interfere with adhesion, and that some window cleaners contain waxes. Clean the glass again yourself, with detergent and lukewarm water and then isopropyl alcohol, and drop a little water on it first: if it beads, a coating is still there.

If a decal has had its time and you want it off, warm it first and peel it low and slow. Our decal care and removal guide has the whole method, and our guide to applying a vinyl decal covers putting the next one on. The car culture shelf is where most of our bumper and window humor lives, from Save the Sticks to Praise the Lowered.