Convertible Top Care
By Prentice St. Clair
There are over four million convertible automobiles on the road today. Every major automotive manufacturer has at least one convertible in its line. Yet most car owners are not aware of any standard operating procedure for the care and maintenance of convertible tops.
When you think about it, the convertible top is simply a piece of cloth or vinyl that is up against everything the environment can throw at it. Of course, manufacturers of convertible tops are aware of this and thus use high-grade and heavy-gauge materials for the convertible top. Nonetheless, anything that we can do to provide extra protection to that material will help it last all the longer.
Equipped with a bit of knowledge, the proper chemicals, and the right procedure, most people find that convertible top care is rather simple and can be quite profitable.
Types of Convertible Tops
There are two main types of convertible tops. The difference is due to the material used, either fabric or vinyl.
One type is the classic top constructed with cloth as the covering material. This material looks and feels like canvas, but is actually woven of fibers that are either synthetic, like acrylic, polyester, olefin, or a synthetic and cotton blend. These fabrics are actually breathable but are made water repellant by a chemical treatment process used during manufacturing. The original repellency breaks down with time and exposure to the elements.
The other type of convertible top is made of thick vinyl. Vinyl is a plastic product composed mostly of polyvinyl chloride (PVC) and made flexible with the addition of plasticizers. The vinyl top may look like a canvas material, but upon close inspection, you can see that the "canvas" is simply an impression stamped into the vinyl when it is manufactured. It is normal for the plasticizers to gradually dry out over time, causing the material to crack and eventually split. With proper care, however, this process can be slowed significantly.
Both types of tops are faced with a myriad of potential contamination sources, including acid rain, heat, ultraviolet rays, smog, tree sap, bird droppings, salt, tar, dirt, grease, grit, and mold. A consistent finding in my research on care of convertible tops is the importance of regular and proper cleaning, which helps to remove the contaminants that can damage the material, as well as regular application of an appropriate protectant, which helps to prevent the contaminants from reaching the material in the first place.
So what Should We Do?
First, it's important, as always, to use the right chemical for the surface of concern. We don't usually use degreaser on the vehicle's paint and we don't use wax to protect leather seats. By the same token, we should use appropriate cleaning and protecting products for the material that makes up the convertible top.
Why is this so important? Automobile manufacturers are receiving warranty claims from owners of convertibles that have disintegrated prematurely. Often this can be attributed to an unwitting car care professional or vehicle owner who uses strong solvents or other harsh cleaners on a regular basis to keep the convertible material clean. Unfortunately, such harsh cleanings tend to break down the material and the stitching that holds the swaths of material together.
I have personally heard of detailers using a bathroom cleaner commonly employed for removing mold stains from tile grout. Unfortunately, the main ingredient in this cleaner is bleach, which is highly corrosive in nature, especially when used in the concentrations in which it is typically sold over-the-counter. Cloth stitching on a convertible top is not nearly as durable as grout and will break down quickly when exposed repeatedly to products containing strong concentrations of bleach.
The fact of the matter is, use of anything other than cleaners designed specifically for convertible tops can cause damage to the material. Even with a milder multi-purpose cleaner, such damage might be minimal, but the concern is the cumulative effect of repeated cleanings with inappropriate chemicals that might lead to the breakdown of the material or the stitching.
So what do we use? To find answers to this question, I did some research. First, there is the owner's manual. Most new vehicles with convertible tops contain care instructions that are surprisingly complete. However, most vehicle owners never bother to check out these instructions. Moreover, older owner's manuals were written before the development of a new set of chemicals for the maintenance of convertible tops and thus offer information that contradicts that provided by newer manuals. I also checked out the information and recommendations of some of the leading manufacturers of the materials that make up the convertible tops.
I found out that there are, indeed, products designed specifically for the cleaning of convertible tops and similar materials like truck tonneau covers. Companies like The Haartz Corporation, which makes the material for virtually all American and European convertible tops, and Roll-N-Lock, a manufacturer of retractable truck bed tonneau covers, exclusively recommend using RAGGTOPP Convertible Top Care Products from Wolfsteins Pro Series for their products.
Additionally, convertible tops need protection just like the paint, leather, or carpeting needs. On fabric tops, it is recommend to use a chemical with a fluorocarbon repelling system. Such a chemical will bond with the fabric and repel liquid and dirt while at the same time providing ultraviolet protection. Look for products that do not contain silicone, Freon, or chlorofluorocarbons (CFCs).
On vinyl tops, a fluorocarbon repelling chemical is not necessary simply because vinyl is not porous. Instead, use an approved product that protects and beautifies the top. Such a product should have ultraviolet blockers that help reduce the cumulative effect of sunlight exposure. It will also enhance the beauty of the top with a dressing effect. However, it is important to not use products that contain silicone, petroleum solvents, or CFCs, all of which can have a negative impact on the vinyl material. RAGGTOPP Vinyl Top Protectant contains no silicone and can be used on all exterior and interior vinyl without streaking.
Additionally, make sure that the products you are using to clean and protect the convertible top are not harmful to paint, glass, chrome or plastic windows. That way, you don't have to worry about overspray or run-off onto the other parts of the vehicle as you proceed with the treatment process described above.
Once you've got the right chemicals for cleaning and protecting convertible tops, the process is quite simple.
Initial Treatment: New Vehicle
Before even getting the vehicle wet, vacuum the convertible top using an upholstery brush to pick up any loose dirt or dust. Next, wet down the top thoroughly and mist it evenly with RAGGTOP ® Fabric/Vinyl Cleaner approved by the manufacturer. If necessary, the cleaner can be lightly agitated using a soft nylon brush.
Rinse the top thoroughly and until all foam from the cleaner dissipates. Allow the top to dry completely. This can be accomplished by simply parking the vehicle in direct sunlight. If this is not possible, you may use forced air from a hair dryer or air mover to assist in speeding up the drying process.
Once the top is thoroughly dry, apply the appropriate RAGGTOPP Fabric Protectant (Fabric or Vinyl) evenly across the entire exposed fabric surface in three light coats, allowing the product to dry 10 minutes or so between coats.
This process will take no more than an hour and can take quite a bit less than an hour depending on drying times.
Reconditioning Treatment: Used Vehicle
If the convertible top is on an older vehicle or has not been appropriately cared for, the top will need to be rejuvenated before adding protection. Simply put, the longer the top has gone without appropriate maintenance, the more attention it will need.
The cleaning process is best done in the shade to assure that the cleaner does not dry out before you have a chance to rinse it off. On a fabric top, start by thoroughly vacuuming the top with an upholstery brush. Then thoroughly wet down the top. Spray it with RAGGTOPP Convertible Top Cleaner. If the top is heavily soiled, you may want to let the cleaner dwell for up to 15 minutes, but make sure it doesn't dry out. Then scrub it gently but thoroughly with a soft nylon brush, using a circular or back-and-forth crisscross motion. Rinse the top thoroughly and until all foam from the cleaner dissipates.
Multiple cleanings using the process above may be necessary to remove as much of the accumulated soil as possible, especially for tops that are several years old. The best way to make sure the top is completely clean before applying protectant is to allow it to dry and visually inspect.
A special case is mold, which grows on the dirt and other foreign material that lingers on the top when it is not regularly cleaned. Detailers who are not familiar with the proper care of convertibles often resort to using strong de-molding cleaners that can damage the top and other vehicle surfaces. In the case of stubborn stains such as mold, special procedures may be necessary.
After all of the cleaning is done, allow the top to dry completely, again by parking the vehicle in direct sunlight or using a hair dryer or air mover. Once the top is thoroughly dry, apply an appropriate protectant evenly across the entire exposed fabric surface. It may be necessary to use up to two times the number of coats recommended for a new top. It's better to apply light coats, allowing ten minutes or so of sun-drying time between coats. This entire process may take from one to two hours, depending on drying times.
Post-Treatment Regular Maintenance
Once the initial treatment is complete, it's important to follow-up with regular re-treatment to keep the convertible top looking great and protected for years to come. Vinyl tops should be properly cleaned and re-treated every four to six weeks for maximum protection. Likewise, fabric tops should be cleaned and retreated every three to six months. Re-treatment on both tops can be accomplished by using the procedures outlined in the "Reconditioning Treatment" section above.
Between formal treatments, standard carwashing is acceptable and advisable. Although most automatic carwashes are safe for convertible tops, those using barrel brushes should be avoided. Nonetheless, hand-washing will ensure the least amount of cumulative wear-and-tear on the convertible top.
Prentice St. Clair offers consulting for the automotive detailing and reconditioning industry. He is recognized as one of the industry's leading experts, having authored several training videos, created training programs, and provided educational sessions for the International and Western Carwash Associations. He continues to provide regular contributions to the industry's trade magazines and offers consulting to automotive detailing operations big and small.