The invention relates generally to a compound and method for repairing damaged plastic and vinyl covered vehicle dashboards and, more specifically, to repair compounds and a two-step repair method for repairing damaged dashboards covered with plastic, vinyl and other similar materials.
Plastic materials such as vinyl have been widely accepted for use as a covering for automobile dashboards. Vinyl and similar plastic materials are advantageous in this application because they are impervious to water, they remain flexible over a broad range of temperatures and they can be produced in a wide variety of colors and finishes.
The use of vinyl materials and the like as a cover for dashboards in automobiles and other vehicles is substantial. Since in such service it will generally be used for an extended period of time, the likelihood of eventual damage is great. Objects such as automobile keys, pens, pencils and toys or heated objects such as matches or cigarettes are obvious causes of such damage. In spite of the fact that such damage may be confined to a small area, the area of the damage is bound to be in an exposed, highly visible region of the vehicle. In spite of the high visibility of such damage, the expense of replacing the entire plastic panel containing the damaged dashboard discourages most consumers from this type of repair. Such damage thus goes unrepaired serving as the situs for tearing and further damage of the dashboard and lowering the overall value of the car or other vehicle.
I have devoted my life to developing materials and methods for effecting repairs on plastic and vinyl articles. For example, in 1973 I obtained U.S. Pat. No. 3,713,926 for a basic process for the in-situ repair of vinyl material. This process comprehends the filling of a damaged area with a heat curable material of 70 percent polyvinyl acetate and 30 percent plasticizer. A graining paper is placed over the patch and sufficient heat is applied to cure the repair compound. My invention disclosed and claimed in U.S. Pat. No. 3,887,413 teaches another, more sophisticated method of vinyl repair which includes the use of a protective paste which is dispersed on the surface of the undamaged material adjacent the damaged area. U.S. Pat. No. 3,975,558 also utilizes a heat insulating paste. A repair method utilizing a heat transfer tool is described in my U.S. Pat. No. 4,181,547. From the foregoing, it is apparent that I have expended substantial effort with relation to materials and processes directed to the repair of vinyl, leather and similar materials.
The field of vinyl repair is an expanding and increasingly sophisticated industry as evidenced by the patent activity of others. U.S. Pat. No. 4,013,495 relates to a method for repairing pigmented and textured flexible material wherein a plurality of thin layers of liquid vinyl repair compound are serially applied and heat cured. U.S. Pat. No. 4,028,160 describes another method wherein precured plastic material is cut into edge abutting patches and used thereto. U.S. Pat. No. 4,086,113 discloses the use of precured patch material, as disclosed in the previous patent, in a preformed patch which is larger than the area of the damaged portion such that it overlaps the damage. The patches are fused to the surrounding undamaged material.
In spite of the innovation of myself and others, certain difficulties still exist. One of the most formidable areas of difficulty relates to the attainment of satisfactory curing and bonding of the repair material. This difficulty is the manifestation of a general problem relating to the proper application of heat. In the processes I have developed, it is frequently difficult to provide an appropriate quantity of heat to properly cure all of the vinyl repair compound in a large and thick area of damage. If the vinyl repair compound has not properly cured, due to insufficient heat application, the service life of the patch will be reduced since the material will not achieve appropriate toughness and the bonding achieved with the adjacent material will be less than optimum which may result in separation of the patch material from the surrounding undamaged material. Excessive application of heat, while ensuring complete curing and bonding of the patch material, will invariably destroy the grain texture of the surrounding material or distort it. Clearly, those processes utilizing precured patch material are intended to alleviate the problems attendant insufficiently cured repair material. However, heat application then becomes an even more exacting process since insufficient heat will result in an insufficient bond between the patch and the surrounding material. Generous heat application such as may be frequently needed to achieve melting and bonding of the patch to the surrounding material may, unfortunately, result in damage to the pattern thereof and distortion of the material just as in processes where heat curing repair materials are utilized.
Beyond the foregoing difficulties, dashboard repair presents a problem relative to matching the hardness of the repair compound, after curing, to that of the surrounding, undamaged dashboard material. The latter is harder than plastic materials, such as vinyl, which are utilized in so many applications including upholstery, luggage, purses and footwear, for which most repair compounds and methods have been developed. Accordingly, currently available vinyl repair compounds are not suited for dashboard repair because the resultant repair patch is significantly softer than the cover material on dashboards.