Method of renovating a series of identical bathtubs

Claim 1

A method of renovation of at least one existing bathtub for multi-unit dwellings or the like, said method comprising in sequence the steps of: lining the exposed exterior surface of the existing bathtub including that portion defining the bathtub cavity with a pliable molding material of a thickness generally equal to that of the liner to be applied to the existing bathtub plus that of the working mold; applying a mass of curable, pliable, initial mold material to the molding material lined existing bathtub to form an initial mold; curing said initial mold, removing said initial mold from said molding material lined bathtub, inverting said initial mold, applying a mold release agent to the outer surface of the initial mold, applying at least one fiberglass and resin layer to said initial mold and curing said resin to form the base material of a working mold, applying a gel coat to the outer surface of the fiberglass and resin working mold and curing said gel coat to complete said working mold, removing the working mold from the initial mold, applying a mold release agent to the gel coat surface of the working mold to a form a portion of a liner and curing said gel coat, applying at least one fiberglass and resin layer to the gel coat on said working mold and curing said resin to complete said liner, removing the finished liner from the working mold, applying adhesive to at least the exposed outer surface of the existing bathtub corresponding to that of the liner, nesting the liner within the existing bathtub, pressing the liner into contact over the full adhesive coated bathtub and curing said adhesive to complete renovation of the bathtub by applying a liner of slightly larger size and of equal configuration to the existing bathtub, removing protruding drain fittings from the exposed surface of said existing bathtub prior to lining of the exposed surface of the bathtub with pliable molding material and forming holes within the fiberglass and resin liner conforming to the drain openings prior to nesting and adhesively fixing the liner to the existing bathtub and completing the renovation of the bathtub by sealably replacing the drain fittings onto the openings within the liner at respective drain locations, and wherein prior to nesting of the liner within the existing bathtub, said method further comprises roughening, cleaning and degreasing the exterior exposed surface of the existing bathtub which receives said liner, and said step of adhesively fixing the liner to the exposed exterior surface of said existing bathtub comprises applying an impervious structural adhesive to the cleaned, roughened surface of the bathtub and an accelerator to the surface of the fiberglass liner which contacts the existing bathtub surface upon nesting of the liner within the bathtub.

Claim 2

A method of renovation of at least one existing bathtub for multi-unit dwellings or the like, said method comprising in sequence the steps of: lining the exposed exterior surface of the existing bathtub including that portion defining the bathtub cavity with a pliable molding material of a thickness generally equal to that of the liner to be applied to the existing bathtub plus that of the working mold; applying a mass of curable, pliable, initial mold material to the molding material lined existing bathtub to form an initial mold; curing said initial mold, removing said initial mold from said molding material lined bathtub, inverting said initial mold, applying a mold release agent to the outer surface of the initial mold, applying at least one fiberglass and resin layer to said initial mold and curing said resin to form the base material of a working mold, applying a gel coat to the outer surface of the fiberglass and resin working mold and curing said gel coat to complete said working mold, removing the working mold from the initial mold, applying a mold release agent to the gel coat surface of the working mold to a form a portion of a liner and curing said gel coat, applying at least one fiberglass and resin layer to the gel coat on said working mold and curing said resin to complete said liner, removing the finished liner from the working mold, applying adhesive to at least the exposed outer surface of the existing bathtub corresponding to that of the liner, nesting the liner within the existing bathtub, pressing the liner into contact over the full adhesive coated bathtub and curing said adhesive to complete renovation of the bathtub by applying a liner of slightly larger size and of equal configuration to the existing bathtub, removing protruding drain fittings from the exposed surface of said existing bathtub prior to lining of the exposed surface of the bathtub with pliable molding material and forming holes within the fiberglass and resin liner conforming to the drain openings prior to nesting and adhesively fixing the liner to the existing bathtub and completing the renovation of the bathtub by sealably replacing the drain fittings onto the openings within the liner at respective drain locations, and wherein prior to nesting of the liner within the existing bathtub, said method further comprises roughening, cleaning and degreasing the exterior exposed surface of the existing bathtub which receives said liner, and said step of adhesively fixing the liner to the exposed exterior surface of said existing bathtub comprises applying an impervious structural adhesive to the cleaned, roughened surface of the bathtub and an accelerator to the surface of the fiberglass liner which contacts the existing bathtub surface upon nesting of the liner within the bathtub.

Claim 6

A method of renovation of a series of identical bathtubs within a multi-unit dwelling or the like, said method comprising the steps of: removing drain fittings protruding outwardly of the bathtub exposed external surface from an existing bathtub, covering the existing bathtub cavity defining surface with adjacent strips of a pliable non-hardening clay material of a thickness of approximately three-eighth inch, applying a mass of wet, pliable plaster of Paris to the surface of the non-hardening clay to form an initial mold, embedding a framework of plastic tubing within the plaster of Paris prior to hardening to reinforce the plaster of Paris initial mold, setting the plaster of Paris and removing the initial mold from the lined existing bathtub, inverting the initial mold and waxing and buffing the outer surface, applying a mold release material to the buffed outer surface of the initial mold, applying fiberglass and uncured resin of slightly less than 3/16 inch thickness to the initial mold to form the base of a working mold, curing said resin, applying a thin gel coat of approximately 20/1000 inch thickness of the fiberglass and resin base to form a working mold of laminate form of approximately 3/16 of an inch in thickness, curing said gel coat, removing said working mold from said initial mold, buffing and waxing the gel coat of said working mold, applying a mold release material to the buffed and waxed gel coat surface of the working mold, applying a gel ocat of approximately 20/1000 inch thickness to the mold release coated working mold, forming at least one layer of fiberglass and uncured resin on the gel coated working mold and curing said at least one fiberglass and resin layer to form with said gel coat a liner of approximately 3/16 inch thickness, curing said liner, removing said liner from said working mold, forming holes within said liner corresponding to the drain openings within said existing bathtub, roughening, cleaning and degreasing the exposed exterior surfaces of the bathtub, applying an impervious waterproof structural adhesive to the abraded surfaces of the bathtub, applying an adhesive accelerator to the surface of the liner which contacts the surface of the existing bathtub during nesting of the liner within the existing bathtub, nesting the liner within the existing bathtub, and applying pressure to the liner to intimately adhesively bond the liner over its full surface with the existing bathtub, curing the adhesive, replacing and adhesively sealing the drain fittings to the holes within the liner; whereby, a thin fiberglass liner of corresponding configuration is intimately bonded to the existing bathtub to form a renovated bathtub of essentially the same size and configuration.

Claim 7

A method of renovation of a series of identical bathtubs within a multi-unit dwelling or the like, said method comprising the steps of: removing drain fittings protruding outwardly of the bathtub exposed external surface from an existing bathtub, covering the existing bathtub cavity defining surface with adjacent strips of a pliable non-hardening clay material of a thickness of approximately three-eighth inch, applying a mass of wet, pliable plaster of Paris to the surface of the non-hardening clay to form an initial mold, embedding a framework of plastic tubing within the plaster of Paris prior to hardening to reinforce the plaster of Paris initial mold, setting the plaster of Paris and removing the initial mold from the lined existing bathtub, inverting the initial mold and waxing and buffing the outer surface, applying a mold release material to the buffed outer surface of the initial mold, applying fiberglass and uncured resin of slightly less than 3/16 inch thickness to the initial mold to form the base of a working mold, curing said resin, applying a thin gel coat of approximately 20/1000 inch thickness of the fiberglass and resin base to form a working mold of laminate form of approximately 3/16 of an inch in thickness, curing said gel coat, removing said working mold from said initial mold, buffing and waxing the gel coat of said working mold, applying a mold release material to the buffed and waxed gel coat surface of the working mold, applying a gel ocat of approximately 20/1000 inch thickness to the mold release coated working mold, forming at least one layer of fiberglass and uncured resin on the gel coated working mold and curing said at least one fiberglass and resin layer to form with said gel coat a liner of approximately 3/16 inch thickness, curing said liner, removing said liner from said working mold, forming holes within said liner corresponding to the drain openings within said existing bathtub, roughening, cleaning and degreasing the exposed exterior surfaces of the bathtub, applying an impervious waterproof structural adhesive to the abraded surfaces of the bathtub, applying an adhesive accelerator to the surface of the liner which contacts the surface of the existing bathtub during nesting of the liner within the existing bathtub, nesting the liner within the existing bathtub, and applying pressure to the liner to intimately adhesively bond the liner over its full surface with the existing bathtub, curing the adhesive, replacing and adhesively sealing the drain fittings to the holes within the liner; whereby, a thin fiberglass liner of corresponding configuration is intimately bonded to the existing bathtub to form a renovated bathtub of essentially the same size and configuration.