The modern roadster is a masterpiece of beauty, performance and superior engineering. We own these wonderful machines because they warm our souls. Like yours, my blood stirs each time I twist the key and the engine comes to life. Top down, sun on my back, wind in my face, eating up the road . . . Could anything be better?
Unlike coupes or sedans, roadsters and convertibles have special requirements. Where the roadster’s and convertible’s fully enclosed brethren sport steel and glass, the topless car has canvas and vinyl. This simple difference creates a myriad of challenges for the soft-top owner.
The first thing to understand about your soft top is its materials. Without this understanding, it’s hard to appreciate the maintenance requirements.
Most modern convertibles and roadsters have soft tops made of a durable polyacrylic/polyester canvas or vinyl. The fabric-like canvas tops feel nice and looks great, while the vinyl tops are more economical and easier to maintain. Fabric tops have a tight weave, but they breathe. Unlike vinyl tops, a canvas top isn’t waterproof, it is only water resistant.
To make the canvas top waterproof, it must be treated. Without protection, canvas tops are susceptible to leaking and stains. Likewise, vinyl tops need protection from the sun and pollutants. If you’re not sure whether your top is fabric or vinyl, check with your dealer.
The rear window on your soft top is also special. Many soft-top cars have rear windows made of a clear vinyl. This allows the window to fold. These types of rear windows will absorb a wide range of gases and liquids, including water, acids and hydrocarbons.
Because vinyl has the ability to absorb foreign materials, it will yellow over time if it’s not properly maintained. Most often, the yellowing and discoloration are the results of ultraviolet (UV) light cross-linking. That is, the vinyl is not directly affected by the sun’s UV rays, but what it absorbs can be.
Convertible Top Killers
Common cleaning products can be very harmful to your soft top. Chemicals you shouldn’t use on or near your top include ammonia, bleach, detergent, alcohol and vinegar.
Detergents, bleach and harsh acids will quickly deteriorate canvas. Others such as ammonia and alcohol will dry and cloud vinyl. Take my word for it, you don’t want to know what it will cost to replace your soft top. So please, know the chemicals you use before you apply them to your top.
How-To Clean Your Convertible Top
Your car’s soft top is subjected to the same environmental conditions as the rest of your car. Although it’s easy to see when your car’s body is dusty and dirty, it is not always easy to see when your top is dirty. This is especially true if it’s black or navy blue.
One of the biggest wear factors for canvas tops is dust which settles into the weave of the fabric and begins to act like sandpaper. Vinyl tops will also experience premature wear from dirt, but not as readily. In general, you should care for your top each time you wash your car. This doesn’t mean you need to scrub it each time, but a good stiff rinsing is necessary.
The following steps are recommended:
- Wash your soft top at least once a month, or when it is dusty or dirty, with a non-detergent-based auto shampoo. If your top is not dirty, rinse it thoroughly with plenty of cool water. Make sure the shampoo does not contain gloss-enhancing oils. Otherwise, the top will absorb the oil and become a dust magnet. The recommended product is Wolfstein’s RaggTopp Cleaner. It’s the only cleaner recommend by the Haartz Corporation, which supplies convertible topping material for virtually every convertible manufactured throughout the world. Haartz has performed exhaustive testing for cleaning and protecting fabric convertible tops.
- The recommended tool for washing is a soft scrub brush. Do not use a cloth, chenille-covered sponge or lamb’s wool mitt because they will leave lint. If your top has soil marks, stains or bird droppings then use a small and stiff upholstery scrub brush. If you can rub the brush across the back of your hand without scratching your skin, it’s safe to use on your soft top. Do not, however, use a scrub brush on the vinyl window. It will scratch. Make sure you rinse the top thoroughly with a stiff stream of water to remove all of the shampoo and dirt.
On canvas tops, dry using a synthetic chamois or microfiber towel. The best method is to use the towel or chamois to blot up the water. Don’t wipe and do not use a terry cloth towel or diaper to dry your canvas top, as they will leave lint. On vinyl tops, a synthetic chamois or microfiber towel will also work well, as will cotton towels. On vinyl windows, microfiber towels seem to work best.
Removing Convertible Top Stains
Sooner or later, your top will be inflicted with a stain that will not come out with regular shampoo. Common stains include bird droppings, tree sap and grease. For these, you will need to use a stronger cleaner that can penetrate and release the foreign matter.
Your first inclination will be to scrub the stain with the regular shampoo. Don’t do it! All scrubbing will do is spread it around. To remove stains from your canvas or vinyl top, use Wolfstein’s RaggTopp Cleaner in full concentration. Spray it liberally on the stain before washing the whole top. Let it soak in, but don’t let it dry. 3 to 5 minutes after applying, rinse your top and wash as usual. You may need to hit the stained area with a stiff stream of water.
Cleaning Your Soft Top Plastic Window
If your convertible is new, no doubt you have experienced the frustration of polyvinyl fog. Polyvinyl fog is created by the evaporation of plasticizers (oily hydrocarbons) and other oils. Plasticizers are used in the manufacturing of vinyl to keep it flexible. They are also used in many car care conditioners to rejuvenate vinyl and plastic.
Plasticizers remain liquid and evaporate with the heat of the sun. This off-gassing is worse with new cars, and then it gradually decreases to a manageable level. Severe off-gassing can also be caused by using too much dressing on your dashboard.
The best tool to clean your convertible’s vinyl window is a non-scratch microfiber towel. Do not use a paper towel, as it can scratch the vinyl. It’s best to detail the window (inside and out) after washing the car.
Follow these steps:
- Rinse the chamois or microfiber towel thoroughly with water to ensure it is clean. Wring out most of the water, but leave it damp. If the chamois is too dry, it will not slide across the window. Microfiber towels are not as temperamental.
- Fold the chamois or microfiber towel into a square. Wipe in one direction across the window. Turn the cloth or chamois, using a clean side with every other pass.
- To clean the inside of the rear window, kneel in the passenger seat (roadster) or in the rear seat (convertible). It may take you a few times to learn the best way. The taller you are, the more difficult it will be.
Protecting Your Convertible Top
As I mentioned earlier, canvas tops are not waterproof. To make a canvas top waterproof and stain resistant, it’s necessary to treat it with a protective spray. The only treatment I recommend is Wolfstein’s RaggTopp Protectant. This is the only fabric protectant that contains an anti-fungus agent to prevent mold and mildew. I have previously recommended Porsche Tequipment Convertible Top Conditioner and 303 High Tech Fabric Guard, however, these products do not offer the same level of protection as RaggTopp. They are also not recommended by the manufacturer of the fabric top material.
Although vinyl doesn’t need waterproofing, vinyl tops do need protection. Using a good vinyl top protectant, you can prevent discoloration damage from road grime, pollution, salt deposits, leaf gum and bird droppings. The two products I recommend for vinyl top protection are Raggtopp Vinyl Protectant and 303 Aerospace Protectant. Both offer excellent UV protection. Vinyl tops should be treated monthly.
Before you spray your soft top with protectant, it must be clean and dry. Use a scrub brush and a full .75-ounce dose of top or car shampoo to deep-clean the top. Applying the canvas top protectant is best done in conjunction with waxing. Your prewax cleaner or polish will remove any potential overspray.
How-to Apply Canvas Convertible Top Protectant
- Mask completely around your top and vinyl window with tape and newspaper. Once dry, the overspray from the protectant is difficult to remove from paint, vinyl and glass. Lift the top slightly and slip newspaper between the top and windshield frame. Do the same between the top and side windows. Use masking tape and newspaper to mask the areas where the top and rear panels meet. Use masking tape and newspaper again to completely mask the rear window (do not leave any vinyl showing).
- Shake the top protectant for 30 to 60 seconds.
- Spray two light coats from a distance of about 7″ to 9″ on the whole top. Start in the center on one side and work toward your body in even, back-and-forth sprays, releasing your finger at the end of each pass. Repeat on the other side. Spray a third light coat on the seams.
- Remove masking materials.
- Check for overspray on paint. Remove any overspray with prewax cleaner or polish.
How-to Apply Vinyl Convertible Top Protectant
- Shake the top protectant for a few seconds.
- Do not spray directly onto the top. Spray or pour the protectant on a foam applicator or sponge. Then use the applicator to apply the protectant to your top. Start in the center on one side and work toward your body in even, back-and-forth wipes. Repeat on the other side.
- Allow the protectant to soak in for 3 to 5 minutes. Then buff dry with a clean microfiber towel or terry cloth detailing towel.
Protecting & Polishing Clear Plastic Windows
Your convertible’s vinyl rear window is fairly delicate. It can be easily scratched with little more than normal use or the wrong cleaning tool. Be sure that any rags you use on your rear window are pure cotton. Don’t use diapers on vinyl. Almost all diapers use polyester thread which will severely scratch the clear vinyl window.
To protect and beautify your soft-top window, it must be polished. I highly recommend Plexus for regular cleaning and light polishing. Although there are numerous plastic polishes and compounds that work, Plexus is quick and easy. For this reason, you are more likely to use it than a polish that takes a lot of time.
To apply Plexus, use a plush terry cloth detailing towel or an old cotton t-shirt.
Follow these simple directions:
- Fold your towel into a square.
- Spray a moderate amount of Plexus on the towel, not directly on the window.
- Work the Plexus into the clear vinyl and allow it to dry for 3 to 5 minutes.
- Turn the towel to a dry side and buff the window until clear.
- If small scratches remain, apply a second coat.
If your window has heavy scratches or slight yellowing, I recommend Meguiar’s Plastic Polish (PlastX).
It’s not necessary to use Plexus with every wash, although many people do. If you’re careful with your window, you may find that every other wash or every third wash, is fine. You cannot overuse Plexus, so don’t be concerned about using it as your everyday cleaner if you drive in a harsh environment.
More Convertible Top Tips & Hints
Proper care of your soft top goes beyond regular maintenance. You can also extend its life and beauty by providing a little extra care when lowering and raising your top.
While today’s engineers have done a wonderful job of designing tops that fold into small spaces, canvas and vinyl tops do not always fold flat. It’s best to lower the top halfway and then smooth the canvas or vinyl to ensure it does not bunch, gather or buckle.
One of the worst enemies of your soft top is itself. When lowered, your vinyl window is in contact with itself. As you drive, road vibrations cause the top to rub together. Over time, this will begin to leave scratches and other marks on the window.
To prevent this, you can use a small piece of fleece or soft cotton (not terrycloth) to protect the window. As you lower your top, after smoothing the wrinkles, lay the fleece across the window.
Convertible Top Care Summary
Your soft top can provide many years of beautiful service, but only if you give it the proper care and handling. Keep your top clean and protect it as needed. When water stops beading on your canvas top, its protection from the sun and water are gone. Vinyl tops need more frequent protecting, as often as once a month.
You may want to look into a car cover especially if you are sporting a convertible!