Patent Abstract:
A method of preparing a sanding block to repair a damaged surface profile. A first step involves finding an undamaged surface profile that matches the damaged surface profile. A second step involves providing a moulding block having a body with a flat surface surrounded by an upstanding flexible peripheral seal to form an enclosure. A third step involves filling the enclosure of the moulding block with hot melt adhesive and, with the hot melt adhesive still mouldable, pressing the moulding block against the undamaged surface profile until the hot melt adhesive solidifies to form a negative image of the undamaged surface profile. A fourth step involves removing the negative image formed of solidified hot melt adhesive from the undamaged surface profile for use as a sanding block.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates to a method of preparing a sanding block to repair a damaged surface profile. 
   BACKGROUND OF THE INVENTION 
   Most automobiles have an exterior surface with either raised or recessed surface profiles. Raised surface profiles, such as outer ridges, are used to accent body lines. Recessed surface profiles, such as channels, are used to accommodate moulding attachments. Should the automobile sustain damage in the vicinity of one of it&#39;s surface profiles, such damage can be difficult to repair. One of the more difficult steps in the repair process is the step of sanding the filler material used for repair to restore the correct surface profile. 
   This problem exists in other fields, as well. It is common for furniture to be provided with decorative surface profiles. It is also common for doors, architectural mouldings, to have decorative surface profiles. 
   SUMMARY OF THE INVENTION 
   What is required is a method of preparing a sanding block to repair a damaged surface profile. 
   According to the present invention there is provided a method of preparing a sanding block to repair a damaged surface profile. A first step involves finding an undamaged surface profile that matches the damaged surface profile. A second step involves providing a moulding block having a body with a flat surface surrounded by an upstanding flexible peripheral seal to form an enclosure. A third step involves filling the enclosure of the moulding block with a mouldable chemical composition (such as hot melt adhesive) and, with the hot melt adhesive still mouldable, pressing the moulding block against the undamaged surface profile until the hot melt adhesive solidifies to form a negative image of the undamaged surface profile. A fourth step involves removing the negative image formed of solidified hot melt adhesive from the undamaged surface profile for use as a sanding block. 
   With the method, as described above, a unique negative image is created to be used as a sanding block for a unique surface profile. 
   Although beneficial results may be obtained through the use of the method, as described above, steps should be taken to protect surfaces which might be sensitive to the use of hot melt adhesives. Even more beneficial results may, therefore, be obtained when the undamaged surface profile is covered with a thin protective layer prior to the moulding block with hot melt adhesive being pressed against the undamaged surface profile. This protective layer can be masking tape, another form of tape, or a protective liquid coating. 
   When the negative image of solidified hot melt adhesive is large, it can be readily grasped. However, when the negative image of solidified hot melt adhesive is more delicate, some other means of grasping is required. Even more beneficial results may, therefore, be obtained when the negative image of solidified hot melt adhesive is mounted a support handle. One way that this can be done is with two sided tape. 
   Although beneficial results may be obtained through the use of the method, as described above, for large elaborate profiles it is preferred that the moulding block being of heat mouldable polymer foam. This enables the moulding block to be heat formed to better follow the contour of the undamaged surface profile, so that less hot melt adhesive is required. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein: 
       FIG. 1  is a perspective view of a sanding block prepared in accordance with the preferred method 
       FIG. 2  is a top plan view of a surface with an undamaged surface profile and a damaged surface profile. 
       FIG. 3  is a perspective view of a moulding block of the sanding block illustrated in  FIG. 1 . 
       FIG. 4  is top plan view of the surface illustrated in  FIG. 2  with the tape in place. 
       FIG. 5  is perspective view of the moulding block illustrated in  FIG. 3  with filled with hot melt adhesive. 
       FIG. 6  is a top plan view of the moulding block being pressed into the surface illustrated in  FIG. 4 . 
       FIG. 7  is an end elevation view of the sanding block illustrated in  FIG. 1 . 
       FIG. 8  is a top plan view of the surface illustrated in  FIG. 2  with filler covering the damaged surface profile. 
       FIG. 9  is a perspective view of an alternative embodiment of sanding block prepared in accordance with the preferred method. 
       FIG. 10  is a perspective view of the moulding block which has been prepared in advance being heated with a heatgun. 
       FIG. 11  is a perspective view of the moulding block with a peripheral seal of rubber tubing. 
       FIG. 12  is a is a perspective view of the moulding block with a peripheral seal of corrugated rubber tubing. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The preferred method of preparing a sanding block to repair a damaged surface profile will now be described with reference to  FIGS. 1 through 12 . 
   The preferred method includes the following steps. 
   Referring to  FIG. 1 , there is method of preparing a sanding block  12  to repair a damaged surface profile generally referenced by numeral  14 . Referring to  FIG. 2 , the preferred method involves finding an undamaged surface profile generally referenced by numeral  16  that matches damaged surface profile  14 . In the illustrated embodiment, damaged surface profile  14  and undamaged surface profile  16  are located on the same portion of detailing trim  18  for a piece of furniture, however other types of surfaces with raised or indented profiles such as those found on autobodies or detailed mouldings for houses could also be repaired using the preferred method. 
   Referring to  FIG. 3 , a polymer foam moulding block  20  is provided that has a body  22  with a flat surface  24  surrounded by an upstanding flexible peripheral seal  26  which forms an enclosure  28 . In the illustrated embodiment, peripheral seal  26  is formed from polymer foam strips  30  which can be peeled off flat surface  24  of body  22  at a later time, although it will be appreciated that peripheral seal  26  could be integral to body  22 . Alternatively, polymer foam strips  22  could be permanent secured to body  22  and trimmed away as desired. Referring to  FIG. 4 , undamaged surface profile  16  is covered with a thin protective layer of masking tape  32 . Masking tape  32  should be carefully smoothed onto undamaged surface profile to eliminating any air bubbles or wrinkles in tape masking tape  32 . In the illustrated embodiment, masking tape  32  is illustrated as being used, however there are other ways to provide a thin protective layer including using a spray protector. 
   Referring to  FIG. 5 , enclosure  28  of moulding block  20  is filled with a mouldable chemical composition. At the present time the cheapest, fastest setting, and most readily available mouldable chemical composition known is hot melt adhesive  34 . Referring to  FIG. 6 , with hot melt adhesive  34  still mouldable, moulding block  18  is pressed against undamaged surface profile  16  until hot melt adhesive  34  solidifies to form what can be termed a negative image or reverse image generally referenced by numeral  36  of undamaged surface profile  16  illustrated in  FIG. 7 . Negative image  36  that is formed of solidified hot melt adhesive  34  is removed from undamaged surface profile  16 . If a surfactant (wet soap) is sprayed onto masking tape  32  prior to moulding block  18  with hot melt adhesive  34  being pressed against the surface, it has been found that it is easier to separate negative image  36  from masking tape  32 . Solidified hot melt adhesive will adhere to flat surface  24  of body  22  of moulding block  18 . Polymer strips  30  of upstanding flexible peripheral seal  26  which were used to form enclosure  28  can be removed to leave negative image  36  of solidified hot melt adhesive  34  spaced from moulding block. Excess solidified hot melt adhesive  34  can be trimmed off. 
   Referring to  FIG. 7 , negative image  36  of solidified hot melt adhesive  34  is mounted to a support handle  38  with two sided tape  40 , although it will be appreciated that other methods (such as glue) can also be used to mount negative image  32  of solidified hot melt adhesive  30  to support handle  42 . The preferred material for support handle  42  is foam, although other materials may also be used. Referring to  FIG. 9 , in instances where sanding block is very small, or where damaged surface profile that is being repaired is in an awkward place, moulding block  18  itself can be trimmed to form handle  42  rather than mount negative image  36  of solidified hot melt adhesive  34  to support handle  38  illustrated in  FIG. 7 . 
   Referring to  FIG. 8 , filler material  44  is placed on damaged surface profile  14 . Referring to  FIG. 1 , support handle  42  is grasped and excess filler material  44  is sanded from damaged surface profile  14  with sand paper  46  that is supported by negative image  36  of solidified hot melt adhesive  34 . 
   Operation 
   The use of preferred method of preparing a sanding block to repair a damaged surface profile will now be described with reference to  FIGS. 1 through 12 . Referring to  FIG. 1 , sand block  12  which is prepared using the above described method can be used in a variety of applications including, the repair of damaged profiles on autobodies, furniture, and exteriors of housing. Moulding block  20  is made of heat mouldable foam and that can be heat formed to follow the contour of undamaged surface profile  16 . This enables moulding block  12  to be customised to suit particular characteristics of damaged surface  14  that is to be repaired and also less hot melt adhesive  34  is required. Referring to  FIG. 4 , thin protective layer of masking tape  32  serves to protect undamaged surface profile from becoming stuck to or damaged by hot melt adhesive  34  during formation of negative image  36 , especially since some hot melt adhesive  34  will escape form enclosure  28  during pressing onto undamaged surface profile  16 . Care taken in carefully smoothing masking tape  32  onto undamaged surface eliminating air bubbles or wrinkles ensures that they will not become an unwanted part of negative image  36 . After negative image  36  is formed, masking tape  32  can be easily removed from undamaged surface profile  16 . Referring to  FIG. 1 , to facilitate sanding with larger sanding blocks  12  sand paper  46  is wrapped around and supported by sanding block  12 . With smaller more delicate sanding blocks, a spray glue is sprayed directly onto negative image  36  and then grit is sprinkled onto the glue to create an abrasive surface that functions as sand paper. 
   Variations 
   Referring to  FIG. 10 , in the alternative, as a matter of convenience, moulding block  20  as described above, can be prepared in advance with enclosure  28  of moulding block  20  being filled with mouldable chemical composition and then moulding block  20  with solidified mouldable chemical composition can be stored until needed. In the illustrated embodiment, solidified mouldable chemical composition is hot melt adhesive  34 , although it will be appreciated that other types of mouldable chemical compositions could also be used. 
   At the time of use, moulding block  20  is then heated with a heatgun  48  until solidified mouldable chemical composition becomes mouldable. In the instance where mouldable chemical is hot melt adhesive  34 , hot melt adhesive  34  turns clear to indicate that it has melted. It should be noted that heat from heatgun  48  can damage polymer foam strips  30  so it is recommended that low heat setting be used. 
   An aluminium support handle  50  can be used to protect the users hands from burns during the process of heating moulding block  20  with heatgun  48 . Aluminium support handle  50  overlies polymer foam moulding block  20  and provides a safe gripping surface  52  to avoid being burned. 
   Furthermore, heat resistant tape  54 , such as Teflon™ treated tape which can be heated to a temperature higher than the temperature required to melt hot melt adhesive  34 , can be used to surround hot melt adhesive  34  during heating. Tape  54  can be used in conjunction with flexible peripheral seal  26  or as an alternative to flexible peripheral seal  26 . Care should be taken to ensure that tape  54  does not inadvertently fold over into hot melt adhesive  34 . Tape  54  serves to contain heated hot melt adhesive  34  during heating. Referring to  FIG. 11 , as an alternative to tape  54 , rubber tubing  56  can also be used. Referring to  FIG. 12 , if desired, rubber tubing  58  or alternatively tape  56  illustrated in  FIG. 10  can corrugated whereby it has alternating ridges  60  and grooves  62  that provide some additional flexibility during the moulding and imprinting process. 
   It will also be appreciated that moulding block  20  could be fabricated from other materials such as dry foam, which is a solid inflexible material. Where moulding block  20  is of a solid inflexible material, a spray or liquid is used as protective layer instead of masking tape  32  illustrated in  FIG. 4 . This is because moulding block  20  that is fabricated of solid inflexible material can only be pressed onto a profile and pulled off whereas moulding blocks  20  that are fabricated from flexible polymer foam can be rolled onto and pealed off of profile due to the flexibility of polymer foam. 
   Referring to  FIG. 6 , the use of moulding blocks  20  prepared in advance as illustrated in  FIG. 10 , is the same as with those moulding blocks  20  which are prepared at the time of use. While hot melt adhesive  34  still mouldable, moulding block  18  is pressed against undamaged surface profile  16  until hot melt adhesive  34  solidifies to form what can be termed a negative image or reverse image generally referenced by numeral  36  of undamaged surface profile  16  illustrated in  FIG. 7 . Negative image  36  that is formed of solidified hot melt adhesive  34  is removed from undamaged surface profile  16 . 
   In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. 
   It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as hereinafter defined in the claims.

Technology Classification (CPC): 8