How to Safely Clean Silly String off Your Car

Silly String Car Cleaning

Can Silly String ruin or damage your car’s paint? It might – and we’ll hit you with a “Nerd Alert” because the next section tells you why Silly String can be as corrosive to vehicle paint as bird poop.

Silly String consists of several primary chemical substances. The addition of a plasticizer (dibutyl phthalate) reinforces the string’s solid structure. A surfactant of silicon or siloxane enables the string to form from the nozzle and be cleaned up easier. A synthetic polymer resin (likely isobutyl methacrylate) is what gives the string its, well, stringy and webby appearance. Colorants are added to give Silly String that “silly” characteristic.

The resin and colorants are the most problematic for car paint. Resin will dry and ruin vinyl tops and can eat away at clearcoats, while the color additives will absolutely leave their mark. For instance, pink Silly String, when sprayed on a car window, will eventually drip and leak pink paint in the rubber sealant separating the glass and door. This effect is worsened with rain.

(TL;DR – Dried Silly String will etch into car paint because of science.)

“Great. Thanks for that, Bill Nye. Now tell me how to get this stuff off my car!”

You got it, boss. Here are some tips to help you remove dried Silly String from your vehicle.  

Rinse Before Washing

Always attempt to remove the visible Silly String with a good rinse. A garden hose is fine for smaller areas, but don’t be afraid to take your pressure washer out to handle windows and hard plastics. If you utilize a power washer to clean your car, be sure the nozzle settings are set correctly, as pressure washing improperly can do more damage to your car than the Silly String itself.

Mild Soap & Water

If you’ve been the victim of last night’s absolutely hilarious Halloween prank, there’s still time to get that Silly String off your car without any damage occurring.

A thorough washing with mild car-safe soap (not dish soap) and water cures most Silly String-related ailments. Be sure to wash and detail your vehicle properly, which means using a clean sponge, clean water and an appropriate wax to seal the clearcoat.

However, if you’ve left the Silly String to bake on your car in the Arizona sun, you might need to break out the big guns (see below).


Silly String can sometimes leave an oily or filmy residue. This is where the magical, do-it-all product, WD-40, comes into play. Spray a little bit on the area in question and wipe it clean with a soft microfiber cloth.

If you get old Silly String in the rubber window seals and plastic trims, spray – say it with me now – WD-40 in the cracks. This will transform the Silly String turn into gummy paste, making it easier to clean. Then use a Q-tip or soft-bristle toothbrush to wiggle the rest out.

(Seriously, WD-40 should be in every auto detailer’s belt.)

Clay Bars

To prevent permanent discoloration after a Silly String fiasco, use a clay bar on your car. This will hopefully remove visible colorants and contaminants before they soak down to your car’s primer coat.

Start by applying spray lubricant made for clay bars on any problem areas. Gently use the clay bar on the lubricant, moving along with the natural “grain” of the paint (horizontal or vertical). Then wipe away the excess lubricant with a microfiber towel and assess if another reapplication is needed.  

Clay bars won’t fix everything, but they could hide any imperfections.

Paint/Lacquer & Enamel Cleaner

Cleaning Silly String off leather seats and upholstery is no easy (or fun) task. It’s downright awful, in fact. Several people have noted that surface cleaners, like DuPont’s Lacquer and Enamel Cleaner, are the best options. In fact, when my kids decided to redecorate the rear leather seats of our Honda Pilot with pink and green Silly String, this is the product I used – and it worked fairly well.

But you should know that using these cleaners come with a few caveats:

First — don’t expect your car’s leather seats to look as pristine as they did before “the incident.” These surface cleaners will probably eat some of the color and luster out of the leather. It’s best to try in an inconspicuous area, like under the seat, before using the product.

Second — the leather will dry out. Immediately after finishing the clean-up, apply a leather cleaning agent or revitalizer and finish it off with a conditioner. Ask your auto detailer for recommendations.

Third — be gentle! As you apply the cleaning agent, your leather seats might begin to tear; either you’re being too aggressive, or the leather is old. Take your time and lay off the elbow grease.

Steam Cleaner

Get Silly String on your convertible top? A steam cleaner may be helpful in removing the caked-on Silly String from the soft-top.

Once removed, you may notice some etching or staining. A liquid fabric cleaner, preferably one that’s specifically created to clean automobiles, should be applied. Agitate the affected areas with a brush. Before finishing, coat the fabric with a hydrophobic (water-resistant) protectant. Voila! You’re done.

Detailing your car and cleaning off Silly String after any Halloween-type prank is an artform. It can be laborious to do, expensive to fix, and absolutely infuriating to deal with. So, the best way to remove Silly String from your car: Don’t let it get Silly String-ed. Put the car in your garage before the trick-or-treaters come through, and you won’t have to worry about it.

Need help? Contact our Valley Honda Dealers to request a recommendation for a good auto detailer in the Phoenix area. As a group of Honda dealerships in Arizona, we know just about every local Joe and Jane in the business, and we’d be happy to get your Silly String-violated vehicle in the right hands.