Patent Publication Number: US-11389817-B2

Title: Epoxy coating system and process for cylindrical items

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. Pat. App. Ser. No. 62/715,880, filed Aug. 8, 2018, titled Method And Apparatus To Finish Cylindrical Articles. 
    
    
     FIELD 
     This invention relates to the field of epoxy coating and more particularly to a system and method for epoxy coating cylindrical items. 
     BACKGROUND 
     Epoxy coatings are useful for both protective and decorative purposes. Epoxy creates a tough and chemical-resistant surface, while strengthening the underlying structure. In the hands of an artist, the coating can also be attractive with a mix of color and patterns. 
     But to create artistic coatings, the epoxy must be applied in a layer thicker than a film, creating the problem of movement. Epoxy is self-leveling, which is a benefit when applied to flat surfaces. But when applied to a sloped or rounded object, the epoxy runs off the surface. Thus, round articles cannot be coated in the protective and artistic way that flat surfaces can. 
     What is needed is a system and method for coating round objects with epoxy. 
     SUMMARY 
     An epoxy coating can be applied to a round surface by keeping the round surface in constant motion, thus defeating the tendency of the epoxy to run off the outer surface of the round object. 
     The process is aided by mechanical equipment that rotates the cylindrical object or item about its center, along an axis, while also permitting adjustment of rotational speed. 
     An explanation of epoxy is helpful. 
     Epoxy is the result of a mix of resin and hardener in a specific ratio. The ration varies by manufacturer. For example, Uvpoxy by EcoPoxy uses a ratio of 1:1. Epoxy from Total Boat Resin uses a ratio of 2:1. Total Boat also has the option of Fast, Medium, and Slow hardeners which may cause a user to choose it as the preferred epoxy. 
     Once mixed, a chemical reaction begins and the mixture begins to stiffen. Thus, timing and order of operations are each important. 
     The process is summarized as:
         Mix—the components are mixed;   Work—the mixture is applied and manipulated until it begins to set;   Set—the mixture is too stiff to manipulate further;   Full dry—the mixture is dry to the touch; and   Full cure—the process of setting is complete.       

     When the mixture changes from a liquid to a gel, it can no longer be manipulated, thus working time ends. 
     Sample times are included in the following table. “TB” is an abbreviation for the manufacturer Total Boat: 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                   
               
               
                   
                 Mix 
                 Work 
                 Set 
                 Full Dry 
                 Cured 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 TB Fast 
                 Varies 
                 10 min 
                 30 min 
                 120 min 
                 48 hour 
               
               
                 TB 
                 Varies 
                 25 min 
                 60 min 
                 180 min 
                 84 hour 
               
               
                 Medium 
               
               
                 TB Slow 
                 Varies 
                 40 min 
                 150 min  
                 300 min 
                  5 day 
               
               
                 Art 
                 Varies 
                 40 min 
                 4-5 
                  8 hrs 
                 72 
               
               
                 Resin 
                   
                   
                 hours 
                   
                 hours 
               
               
                 Ecopoxy 
                 Varies 
                 40 min 
                 2-3 
                  4-6 hours 
                 72 
               
               
                   
                   
                   
                 hours 
                   
                 hours 
               
               
                   
               
            
           
         
       
     
     Next, discussion turns to the mechanical components that allow a user to execute the method. 
     The primary component is a motor with optional gearbox that rotates an axle, the axle in turn rotating an internal support that interfaces with the cylindrical object. The motor optionally includes variable speed and reversible direction. As a further option, the motor may use a controller to automatically reverse the direction of rotation following a certain number of rotations. For example, five rotations clockwise, then five rotations counter-clockwise, then five rotations clockwise, and so forth. 
     The motor and gearbox must generate sufficient torque to rotate an out-of-balance object because during application of the epoxy mixture sections of the cylindrical object will have excess epoxy. This excess epoxy will weigh down the associated section, thus resisting rotation. The motor and gearbox must overcome this opposing torque to maintain rotational speed. Insufficient torque will result in surging, or inconsistent rotational speed. 
     The axle is supported on each end by bearings or blocks. The axle defines the axis of rotation. 
     Optionally, additional axles are used to rotate additional objects. This allows the user to coat multiple objects in a similar manner, thus creating matching items. 
     The internal support, bridging the space between the axle and the cylindrical object, can take multiple forms. 
     A first form is an inflatable bladder. The inflatable bladder is inflated using air passed through a hollow axle, exiting the axle into the center of the bladder. 
     Inflation of the bladder presses the outer surface of the bladder against the inner surface of the cylindrical article, creating a mechanical connection. 
     A second form of internal support is expanding arms. The arms are rotationally fixed with respect to the axle, with feet that can move outward to press against the interior surface of the cylindrical article. 
     A third form of internal support is a spoked wheel, or other type of disk. This support is most useful for objects that have a narrow band of internal surface, and thus are difficult to hold with the methods described above. For example, a ring of material. 
     A fourth form of support is an external support, used for solid objects such as drumsticks. The drumstick is inserted into a chuck, which grips a section of its outer surface using a foam or other deformable material. 
     A fifth form of support is similar to that used for a wood-working lathe, with an adjustable chuck at one end and pointed axle/tail-stock at the opposing end. 
     Using the above mechanism, the process is as follows: 
     First, the cylindrical object is mounted in place using a support affixed to the axle. 
     Next, the cylindrical object is optionally coated with a tinted quick-dry resin to prepare the surface. The use of a quick-dry resin is most critical for porous surfaces. 
     The quick-dry resin is preferably an epoxy with a fast-set time to reduce the opportunity for the introduction of air bubbles. Application may be by brush or spray. 
     Once dry, the quick-dry resin is sanded to even out any raised grain that may have been created by absorption of the quick-dry resin. 
     Next, an optional background coat is applied. Note that this is the first layer of material, and thus the lowest layer of the final product. The background may include the addition of particulates, such as glitter. 
     Next, epoxy application then begins. 
     For each layer, the user chooses between a fast or slow setting epoxy. 
     Fast-setting epoxies are preferred for elements of the image that are smaller or defined by a single color. For example, a beach or a sky. The faster set is preferred to minimize mixing with subsequent layers and reduce the wait time for application of subsequent layers. 
     Slow-setting epoxies are preferred for broad scenes that may use multiple epoxies that are mixed during and after application. The slower setting time allows the user greater flexibility to manipulate the epoxy. Slow-setting epoxy is also preferred if a thinning color additive is used because some additives will thin the epoxy mixture and increase the set time, but others will thicken and decrease the set time. A slow-setting epoxy is more tolerant of these changes because the slower set time allows heat to leave the epoxy mixture gradually, no matter how the tint affects the behavior of the epoxy. 
     Having chosen the desired epoxy, the user mixes the resin and hardener. The user optionally mixes in solids, such as glitter, golf leaf, pearl, or powders. The user may also optionally mix in liquids, such as alcohol-based tints, or paint. 
     Next, rotation is started of the cylindrical object. 
     The user then begins to apply the epoxy mixture. The epoxy mixture is poured onto the rotation surface of the cylindrical object, where it is then manipulated. 
     Manipulation can take the form of direct contact from a finger, brush, or stick, or indirect contact using hot air—which thins the epoxy—or air from a compressor or blown through a straw. 
     Manipulation can continue until the epoxy sets, at which time it is too thick to be readily manipulated. 
     The user can then begin preparation of the next layer, repeating the steps of choosing an epoxy, mixing, and applying while the underlying layer continues to harden until fully cured. 
     When the user has completed application of epoxy, the cylindrical object is allowed to continue to rotate until fully set, although not yet dry. This step is estimated to require between six and eight hours. 
     After the underlying epoxy is dry, a protective coating of clear epoxy is applied. The protective coating is applied using a notched trowel to ensure the correct thickness. If too little is applied, crater or depressions will form. If too much is applied, ridges and bulges will form. 
     This protective layer is then allowed to dry. 
     Epoxy creates heat during the chemical process of curing. To take advantage of this property, a temperature sensor is optionally used to monitor the temperature of the curing epoxy. When a low temperature is detected, rotation is stopped. 
     The benefit of epoxy application is not only artistic, but also mechanical. For example, when drums, such as those used for music, receive an epoxy coating the result is a drum with increased resonance and a decreased delay between a hit and the drum reaching its final pitch. 
     Coated drum sticks are softer and more-comfortable to grip than uncoated sticks. Additionally, as a user holds the drum sticks, the body heat of the user warms the epoxy coating, making it tacky and more easily gripped by the user. 
     Discussion now turns to a detailed description of an embodiment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. 
       The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
         FIG. 1A  illustrates a first step of the epoxy coating method. 
         FIG. 1B  illustrates a second step of the epoxy coating method. 
         FIG. 1C  illustrates a third step of the epoxy coating method. 
         FIG. 1D  illustrates a fourth step of the epoxy coating method. 
         FIG. 1E  illustrates a fifth step of the epoxy coating method. 
         FIG. 1F  illustrates a sixth step of the epoxy coating method. 
         FIG. 1G  illustrates a seventh step of the epoxy coating method. 
         FIG. 1H  illustrates an eighth step of the epoxy coating method. 
         FIG. 1I  illustrates a ninth step of the epoxy coating method. 
         FIG. 1J  illustrates a tenth step of the epoxy coating method. 
         FIG. 2  illustrates a flow chart of the epoxy coating method. 
         FIG. 3  illustrates a rotational speed chart of the epoxy coating method. 
         FIG. 4  illustrates a first view of the epoxy coating apparatus. 
         FIG. 5  illustrates a second view of the epoxy coating apparatus. 
         FIG. 6  illustrates a first view of adjustable stabilizing legs of the epoxy coating apparatus. 
         FIG. 7  illustrates a second view of adjustable stabilizing legs of the epoxy coating apparatus. 
         FIG. 8  illustrates a third view of the epoxy coating apparatus. 
         FIG. 9  illustrates a view of a stabilizing mount for shallow objects to be coated using the epoxy coating apparatus. 
         FIG. 10A  illustrates a drum before coating of the epoxy coating apparatus. 
         FIG. 10B  illustrates a drum after coating of the epoxy coating apparatus. 
         FIG. 11A  illustrates a first set of coated objects of the epoxy coating apparatus. 
         FIG. 11B  illustrates a second set of coated objects of the epoxy coating apparatus. 
         FIG. 11C  illustrates a third set of coated objects of the epoxy coating apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
     Referring to  FIG. 1A , a first step of the epoxy coating method is shown. 
     The epoxy coating apparatus  1  is shown before any epoxy has been added. 
     The rotation apparatus  10  includes axle  12 , the free end of which rotates on, or within, a block  14 . 
     The opposite end of the axle  12  connects to the motor  18  with optional rotational speed and direction controls  20 . 
     A cylindrical item  30  is held using an internal support  36  that bridges the distance between the axle  12  and the cylindrical item  30 . 
     Referring to  FIG. 1B , a second step of the epoxy coating method is shown. 
     User one  130  is applying epoxy mixture  100  by pouring from an epoxy container  102 . User two  132  is using a notched trowel  104  to spread the epoxy mixture  100  while maintaining a constant thickness. 
     On a flat, horizontal surface, the epoxy resin can be allowed to sit and self-level, creating an even thickness. But on the rotating surface of the cylindrical object  32 , a notched trowel helps to ensure even application. 
     Referring to  FIG. 1C , a third step of the epoxy coating method is shown. 
     User one  130  and user two  132  are removing any lines left by the notched trowel  104  (See  FIG. 1B ) using gloves  110 . 
     Referring to  FIG. 1D , a fourth step of the epoxy coating method is shown. 
     A new section of epoxy mixture  100  is being applied in a different section of the cylindrical item  30 . 
     Referring to  FIG. 1E , a fifth step of the epoxy coating method is shown. 
     User one  130  is using a brush  106  to add on isolated items, such as images of clouds. User two  132  is using a notched trowel  104  to even out the section of epoxy mixture  100  applied in the previous step. 
     Referring to  FIG. 1F , a sixth step of the epoxy coating method is shown. 
     User one  130  is using a straw  108  to blow across the epoxy mixture  100 , spreading and creating effects. 
     Referring to  FIG. 1G , a seventh step of the epoxy coating method is shown. 
     User one  130  and user two  132  are each applying epoxy mixture  100  using an epoxy container  102   
     Referring to  FIG. 1H , an eighth step of the epoxy coating method is shown. 
     User one  130  is blending the two epoxy resins  100  applied in the previous step, using gloves  110 . 
     Referring to  FIG. 1I , a ninth step of the epoxy coating method is shown. 
     User one  130  and user two  132  are applying small amounts of epoxy mixture  100  using sticks  112 . 
     Referring to  FIG. 1J , a tenth step of the epoxy coating method is shown. 
     User one  130  is applying final touches using a brush  106 . 
     The cylindrical item  30  is then allowed to rotate until the epoxy resin has fully set. 
     Referring to  FIG. 2 , a flow chart of the epoxy coating method is shown. 
     Application of layers of epoxy resin is a progressive process, in particular for layer that the user does not want to mix. For example, a lower layer of dark epoxy and an upper layer of lighter epoxy resin that, if mixed, would lose their contrast. 
     The application of layer  1 , the first and lowest layer, starts with the layer  1  epoxy mixing interval  160 . 
     Then begins the layer  1  epoxy setting interval  162 , during which the epoxy resin is in liquid form and ready to apply and be manipulated. This interval ends when the epoxy has cured to stage where the epoxy is too thick to manipulate. 
     The epoxy is then allowed to partially cure during the layer  1  epoxy curing interval  164 . 
     With layer  1  partially cured, a second layer can be mixed and applied. Thus, layer  2  passes through the layer  2  epoxy mixing interval  170 , layer  2  epoxy setting interval  172 , and layer  2  epoxy curing interval  174 . 
     Then, with layer  2  partially cured, layer  3  passes through the layer  3  epoxy mixing interval  180 , layer  3  epoxy setting interval  182 , and layer  3  epoxy curing interval  184 . 
     Referring to  FIG. 3 , a rotational speed chart of the epoxy coating method is shown. 
     The cylindrical item  30  rotates  140  during application of the epoxy mixture  100 . An appropriate speed of rotation is important to ensure the epoxy mixture  100  dries evenly, but also is not ejected off the surface of the cylindrical item  30 . 
     If the speed is an excessive rotation speed  148 , a wet epoxy mixture  100  will be ejected off the outer surface  32  of the cylindrical item  30 . 
     The working range rotation speed  146  of between two and four RPM (Revolutions Per Minute) is the ideal range for an epoxy mixture  100  during application. The speed is then increased to between five and ten RPM for between one and four minutes to allow the epoxy mixture  100  to level without falling off the cylindrical item  30 . 
     When the epoxy mixture  100  has moved from the setting interval  162  to the curing interval  164  (see  FIG. 2 ), the speed can be reduced to the curing range rotation speed  144  of between one and two RPM. 
     Rotation  140  must be maintained at a high enough speed to ensure consistent thickness of the epoxy mixture  100 . If the rotation speed drops to an insufficient rotation speed  142 , a wet epoxy mixture  100  will fall off the surface, and a partially cured resin will cure in inconsistent thickness. 
     Referring to  FIG. 4 , a first view of the epoxy coating apparatus is shown. 
     The rotation apparatus  10  is shown with bladder  40 . The bladder  40  includes an end surface  42 , a perimeter surface  44 , connected by a transition  46 . 
     An air valve  48  is used to inflate the bladder  40 . Air is preferably provided to the air valve  48  through a drive shaft with internal air passage  50 . 
     A bladder coupler  52  connects the air valve  48  to the bladder  40 . 
     Also shown is a location for secondary item rotation  80 , shown with a drumstick  82  inserted into a chuck  84 . By rotating two items together, epoxy mixture  100  may be mixed and applied to the items simultaneously, ensure that the items match each other. 
     The secondary item rotation  80  and drive axle  24  are connected by pulleys  26  and belts  28 . 
     A motor  18  with optional gearbox  22  rotates the drive axle  24 . 
     Referring to  FIG. 5 , a second view of the epoxy coating apparatus is shown. 
     A cylindrical item  30  is mounted on bladder  40 . Again shown are air valve  48 , drive shaft with internal air passage  50 , and bladder coupler  52 . 
     Referring to  FIGS. 6 and 7 , a first and second view of adjustable stabilizing legs of the epoxy coating apparatus are shown. 
     The adjustable legs  60  include primary hinges  62  between the primary arms  64  and the primary sliding coupling  66  that moves along the drive axle  24 . 
     Each primary arm  64  ends in a foot  68  connected by a foot hinge  67 . 
     Secondary hinges  70  connect each secondary sliding coupling  72  with its connecting arm  74 . Tertiary hinges  76  connect each connecting arm  74  with the fixed coupling  78 , which is set in position on the drive axle  24 . 
     The movement of primary sliding coupling  66  along the drive axle  24  moves the feet  68  toward and away from the drive axle  24 , allowing the adjustable legs  60  to grip the inner surface  34  of cylindrical items  30  of differing sizes. 
     Referring to  FIG. 8 , a third view of the epoxy coating apparatus is shown. 
     The motor  18  and gearbox  22  are shown connected to the drive axle  24 , which is in turn connected with pulleys  26  and belts  28  to locations of secondary item rotation  80 , which are supported by bearings  16 . Shown here as secondary items are drumsticks  82  inserted into chucks  84 . 
     Referring to  FIG. 9 , a view of a stabilizing mount for shallow objects to be coated using the epoxy coating apparatus is shown. 
     When the cylindrical item  30  is shallow, it may be affixed to a support arms  90  held using spoked support  92 . 
     Referring to  FIG. 10A , a drum without the epoxy coating. Referring to  FIG. 10B , a drum after coating of the epoxy coating apparatus is shown. 
     The uncoated drum  200  is a traditional vinyl-wrapped drum. Below the uncoated drum  200  is a decibel chart of the sound produced when the drum is struck. The drum is struck at moment  210 , with the sound that follows being the drum head and shell resonating. 
     The coating drum  202  is the same drum, but with the vinyl wrap removed and the epoxy coating applied as described herein. The drum is struck at moment  210 . The resonance shown in the chart indicates a truer and stronger note and tone. This effect occurs because the epoxy coating reduces the tendency of the plywood shell of the drum to vibrate, instead increasing the resonance between the upper and lower head of the drum. The result is a stronger, truer, deeper and longer-lasting note that is noticeable to the ear. 
     Referring to  FIG. 11A , a first set of coated objects of the epoxy coating apparatus is shown. 
     Coating drums  202  and drumsticks  82  are shown. 
     Referring to  FIGS. 11B  and C, a second and third set of coated objects of the epoxy coating apparatus are shown. 
     The artistry associated with the use of the disclosed method is evident. 
     While the beauty of the resulting item will vary depending on the skill of the user, the protective quality is consistent. 
     Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
     It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction, and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.