Method and system for manufacturing a boat mould by additive manufacturing

Abstract

An additive manufacturing method according to the present invention includes feeding a material into an extruder of an additive manufacturing apparatus, heating the material to form a flowable material, depositing a first layer of the flowable material from a nozzle of the additive manufacturing apparatus to form a portion of a hull portion of a plug for the ship item, depositing a second layer of the flowable material from a nozzle of the additive manufacturing apparatus to form a portion of a deck portion of the plug for the ship item, and machining the hull portion and the deck portion using the additive manufacturing apparatus.

Description

[Technical field]

[0001] This application claims the benefit of priority to U.S. Patent Application No. 16 / 796,366, filed February 20, 2020, which is incorporated herein by reference in its entirety.

[0002] Aspects of the present disclosure relate to apparatus and methods for manufacturing components, in some instances, apparatus and methods for manufacturing components (e.g., marine products or components, automotive parts, medical devices, mechanical components, consumer goods, etc.) by additive manufacturing techniques or processes, also known as 3D printing manufacturing techniques or processes. [Background technology]

[0003] Additive manufacturing techniques and processes generally involve building up one or more materials to create net-shape or near-net-shape (NNS) objects, as opposed to subtractive manufacturing methods. Although "additive manufacturing" is an industry standard term (ASTM F2792), additive manufacturing encompasses a variety of manufacturing and prototyping techniques known by a variety of names, including freeform fabrication, 3D printing, rapid prototyping / tooling, etc. Additive manufacturing techniques are used to produce simple or complex components from a wide variety of materials. For example, freestanding objects can be manufactured from computer-aided design (CAD) models.

[0004] A particular type of additive manufacturing is commonly known as 3D printing. One such process, commonly referred to as Fused Deposition Modeling (FDM), involves melting a thin layer of thermoplastic material and applying this material in multiple layers to produce a final part. This is usually accomplished by passing a continuous thin filament of thermoplastic material through a heated nozzle, which melts the material and applies it to the structure to be printed. A thin layer of heated material is applied to an existing structure such that it melts and fuses with the existing material to produce a solid finished part.

[0005] The filaments used in the above-mentioned processes are typically produced using a plastic extruder, which includes a specially designed screw that rotates inside a heated steel barrel. Thermoplastic material in the form of small pellets is introduced into one end of the rotating screw. Friction from the rotating screw, combined with heat from the barrel, softens the plastic, which is then forced under pressure out of a small rounded opening in a die attached to the front of the extruder barrel. This extrudes a string of material, which is then cooled and coiled for use in a 3D printing machine.

[0006] Melting thin filaments of material to 3D print products is a slow process that is suitable for producing relatively small products or limited numbers of products. The molten filament approach to 3D printing may be too slow for producing large products. However, the basic process of 3D printing using molten thermoplastic material offers advantages for producing large parts or large numbers of products.

[0007] In some instances, 3D printing of a part involves a two-step process. In some aspects, 3D printing may utilize a large print bead to achieve the exact final size and shape. This two-step process, commonly referred to as near net shape, begins by printing the part to a slightly larger size than required, and then machining, milling, or routing the part to the final size and shape. The additional time required to trim the part to the final size is offset by the faster printing process.

[0008] The print head of an additive manufacturing machine used to print relatively large beads of thermoplastic material includes a vertically mounted extruder and a print nozzle that directs a rounded print bead downward onto the surface or part to be printed. In some cases, the flowable material, e.g., molten thermoplastic material, is injected together with a reinforcing material (e.g., fiber strands) to increase the strength of the material. The flowable material is deposited onto a substrate (e.g., a mold) while it is hot and pliable, and then pressed downward or otherwise flattened and / or leveled to the same thickness every time. These conventional print heads may include a vibrating plate surrounding the nozzle, which is configured to vibrate up and down, thereby pressing and flattening the bead of material against the previous layer of material. This deposition process is repeated, depositing each successive layer of flowable material onto the existing layer to build up and manufacture the desired structure of the component or part. To achieve proper bonding between the printed layers, it is necessary to ensure that the temperature of the previously deposited layer is within a certain range. For example, the previously deposited layer must be cooled to an appropriate temperature so that it is solid enough to support the new layer, but is also hot enough to soften and fuse with the new layer, thus producing a solid part at the end of the manufacturing process.

[0009] One industry that benefits from additive manufacturing is boat manufacturing. Today, boats are made up of multiple components that are manufactured using molds. Reinforced plastic materials, such as fiberglass, are injected into the molds. The separate components formed in the molds are then joined together to form the finished boat. These boats are generally made of two main components: the hull and the deck. The hull comprises or constitutes the exterior of the boat that floats on the water, and the deck comprises or constitutes the interior of the boat. In a typical recreational boat, the shape of the deck closely conforms to the shape of the interior surface of the hull and forms the area where passengers can stand. Seats or other features are molded into the deck. Thus, the boat is constructed by rigidly connecting the separate hull and deck components together.

[0010] Traditionally, fiberglass boats are manufactured by applying a catalyzed fiberglass material to the inside of a mold, which has a surface that conforms to the desired shape of the exterior of the part. The material is then cured and the resulting part, e.g., the hull of a boat, is removed from the mold.

[0011] Before a boat, such as a fiberglass boat, is manufactured in this manner, a mold for the hull and a mold for the deck are typically made. This is generally accomplished by creating a pattern called a "plug" that has the size and shape desired for the final component. Fiberglass may then be applied to the plug. When the fiberglass is cured and removed from the plug, the resulting fiberglass part forms the mold for that component.

[0012] Typically, these plugs are made using wood, foam, and other materials in a relatively time-consuming and expensive process that requires skilled craftsmanship. This conventional process can take months or years to complete. Also, for a boat made in this manner, two separate plugs are required: one for the hull and one for the deck. In addition, the conventional manufacturing process can result in plugs for boats that are not durable. Wear and tear caused by the process of making the molds on such plugs can limit the number of molds that can be pulled from each plug before the plug deteriorates to the point where it can no longer be used. This process can be improved by a large-scale 3D printing process that produces a single plug for both the hull and the deck. Summary of the Invention

[0013] Aspects of the present disclosure relate in particular to methods and apparatus for manufacturing components by additive manufacturing or 3D printing techniques. Each aspect disclosed herein may include one or more of the features described in relation to any other aspect disclosed. An object of the present disclosure is a method for using a large scale 3D printing process to manufacture plugs for boats in a faster and cheaper manner, which is performed by machines rather than skilled craftsmen. Additionally, this method can produce plugs that are more durable than plugs formed by conventional processes.

[0014] This approach may use an additive manufacturing process, such as a 3D printing process, to print the hull and deck. The hull and deck are manufactured as a single piece with a shape that closely matches the final boat. A CNC machine is then used to machine the printed structure to the desired final dimensions and shape, and subsequently attached to a rotating support that suspends the part above the floor and allows the part to be rotated so that either the hull or deck is facing up as desired.

[0015] When the hull is up, fiberglass can be applied and a mold for the hull can be made from the printed plug. When the plug is rotated and the deck is up, fiberglass can be applied and a mold for the deck can be made. In this way, a single plug can be used to make both the hull and the deck.

[0016] Because the material used to print the double-sided plugs is significantly more durable than traditional materials commonly used to make boat plugs, the material for the double-sided plugs can be used to manufacture a significant number of molds without degradation. The 3D printing process and subsequent machining is significantly faster than traditional approaches, reducing the time required to make the plugs.

[0017] It is also possible to design features for the deck that cannot be easily printed as part of the initial printing process. Alternatively, as a variation, if desired, these features can be printed as separate articles and then attached or bonded to the printed deck to produce a deck plug with any desired features.

[0018] In one aspect, an additive manufacturing method includes feeding a feedstock to an extruder of an additive manufacturing device, heating the feedstock to form a flowable material, and depositing a first layer of the flowable material from a nozzle of the additive manufacturing device to form a portion of a hull portion of a plug for a marine article. The method may also include depositing a second layer of the flowable material from a nozzle of the additive manufacturing device to form a portion of a deck portion of the plug for the marine article.

[0019] In another aspect, a system for manufacturing a mold for a marine product includes a plug formed of a thermoplastic material and a support configured to rotatably suspend the plug, the plug including a hull portion and a deck portion integrally formed with the hull portion, the hull portion having a hull surface oriented in a first direction and the deck portion having a deck surface oriented in a second direction opposite the first direction, the hull portion and the deck portion each being formed of a thermoplastic material.

[0020] In yet another aspect, a method of manufacturing a mold includes feeding a feedstock to an extruder of an additive manufacturing device and heating the feedstock to form a flowable material. The method may include depositing the flowable material from a nozzle to form a plug including a hull portion and a deck portion, applying a plastic material to at least one of the hull portion or the deck portion of the plug, hardening the plastic material, and removing the hardened plastic material from the plug to form the mold.

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary aspects of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view of an exemplary additive manufacturing apparatus operable according to an additive manufacturing process for forming an article according to one aspect of the present disclosure. [Diagram 2] FIG. 2 is a perspective view of an example carrier / extruder assembly of the example additive manufacturing apparatus shown in FIG. [Diagram 3] FIG. 2 is an enlarged perspective view of an example carrier / applicator assembly of the example additive manufacturing apparatus shown in FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view of the exemplary applicator head assembly shown in FIG. [Diagram 5] FIG. 2 is a perspective view of a plug having a hull portion and a deck portion. [Figure 6A-6B] FIG. 6A is a plan view of the plug of FIG. 5 with the hull facing up, and FIG. 6B is a side view of the plug of FIG. 5 with the hull facing up. [Figure 7A-7B] 7A is a plan view of the plug of FIG. 5 with the top facing up, and FIG. 7B is a side view of the plug of FIG. 5 with the top facing up. [Figure 8] FIG. 1 is a perspective view of a plug with a separate console. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present disclosure relates, inter alia, to methods and apparatus for manufacturing multiple components by additive manufacturing or 3D printing techniques. In particular, the methods and apparatus described herein include approaches using large scale 3D printing processes to make plugs for boats in a fast, inexpensive manner and using machines to produce durable plugs.

[0024] 1, an additive manufacturing apparatus 1 (e.g., a CNC machine) includes a bed undercarriage having a pair of transversely spaced sidewalls 21, 22, a printing gantry 23, a trimming gantry 36, a carriage 24 mounted to the printing gantry 23, a carrier 25 mounted to the carriage 24, an extruder 61, and an applicator assembly 43 mounted to the carrier 25. The printing gantry 23 and the trimming gantry 36 may be supported by the sidewalls 21, 22. A horizontal work table 27 includes a support surface disposed in the XY plane and is supported on the bed undercarriage between the sidewalls 21, 22. The printing gantry 23 and the trimming gantry 36 are disposed to extend along the Y axis and are supported at their respective ends by the pair of sidewalls 21, 22. The printing gantry 23 and the trimming gantry 36 may be movable in the X-axis direction on a set of shared, generally parallel guide rails 28, 29 provided on the upper ends of the side walls 21, 22. The printing gantry 23 and the trimming gantry 36 may be moved by one or more (e.g., a set of) servo motors attached to the printing gantry 23 and the trimming gantry 36, respectively. For example, the printing gantry 23 and the trimming gantry 36 may be operatively connected to tracks provided on the side walls 21, 22. The carriage 24 is supported by the printing gantry 23 and has a support member 30 attached to one or more guide rails 31, 32, 33 provided on the printing gantry 23 so as to be movable along them. The carriage 24 may be movable along the Y axis along one or more guide rails 31, 32, 33 via a servo motor which may be mounted on the print gantry 23 and operatively connected to the support member 30. The carrier 25 may be mounted on a set of vertically spaced guide rails 35 supported by the carriage 24 for movement of the carrier 25 along the Z axis relative to the carriage 24. The carrier 25 may be movable along the Z axis via a servo motor which may be mounted on the carriage 24 and operatively connected to the carrier 25. A vertical work table 37 may be attached to one or more conveyor belts 38, 48.A vertical work table 37 is supported on top of the horizontal work table 27 and is movable along rails 39, 40 along the X axis by one or more servo motors which may be coupled to the vertical work table 37 and operatively connected to tracks provided on the top of the bed undercarriage.

[0025] As best shown in FIG. 2, the extruder 61 may be mounted to the carrier 25 in a linearly movable manner. In an exemplary embodiment, the extruder 61 may be movably mounted on a set of rails 34, 35 and bearings (FIG. 1). A servo motor 98 may drive the extruder 61 through a gear box 99 mounted to a translation housing 97. The extruder 61 receives thermoplastic pellets at the feed housing 44, and the extruder screw moves the thermoplastic material down through the barrel 42 where it may be melted by friction of the screw and by the heater 41. The molten thermoplastic material flows through the extruder 61 to a positive displacement gear pump or melt pump 62 (FIG. 3).

[0026] As best seen in FIG. 3, the gear pump 62 is mounted so as to be fixedly attached to the bottom of the carrier 25. The gear pump 62 may be driven by a servo motor 63 via a gear box 64 to receive molten plastic (e.g., thermoplastic material) from an extruder 61 (FIG. 2) and deliver a precisely metered amount of thermoplastic material at a predetermined flow rate to the nozzle 51 for printing the part. The applicator head 43 may be mounted in a position below the gear pump 62. The applicator head 43 may include a bead forming roller 59 rotatably mounted to the carrier bracket 47. The bead forming roller 59 provides a means for flattening and leveling the sizable bead of fluid material (e.g., molten thermoplastic material) extruded from the nozzle 51. The carrier bracket 47 may be configured to be rotationally moved by the servo motor 60 via a pulley or sprocket 56 and belt or chain 65 arrangement.

[0027] 4, the applicator head 43 includes a housing 46 having a rotary coupling mounted therein. A pulley or sprocket 56 may be machined into an inner hub 76 of the rotary coupling. The inner hub 76 may have an opening with a diameter large enough for the heated print nozzle 51 to pass through. The inner hub 76 may rotate on a set of bearings 49 housed within an outer housing 75 of the rotary coupling. A pressure roller assembly may be mounted on the inner hub 76 of the rotary coupling such that the pressure roller 59 rotates around the print nozzle 51. The rotary coupling also includes barb fittings 67, 68 which lead to a coolant passage 70 which surrounds or encircles the inner hub 76 of the rotary coupling and encircles the inner surface of the outer housing 75 of the rotary coupling. The coolant passage 70 may extend into the shaft 73 of the pressure roller 59 to a quick change coupling 72 .

[0028] 2-4, an oversized molten bead of flowable material (e.g., molten thermoplastic material) is provided under pressure from a source disposed on carrier 25 (e.g., gear pump 62) or other source. The bead of flowable material is provided to applicator head 43. Thus, gear pump 62 (or other source of flowable material) is rigidly coupled to and in communication with nozzle 51. In use, flowable material 53 (e.g., thermoplastic material) is heated sufficiently to form a large molten bead, which is extruded from applicator nozzle 51 to form a large, uniform, smoothly deposited column of material on surface 27. In some aspects, surface 27 is a horizontally extending surface (e.g., a surface in the XY plane as shown in FIG. 1). In other aspects, a vertically extending surface 37 (e.g., a surface in the YZ plane as shown in FIG. 1) may be used instead of or in addition to surface 27. 4, each of surfaces 27, 37 is adapted to receive a bead of flowable material 53. Such bead of molten material, along with the layers forming the 3D printed product, such as a boat plug, is flattened, flushed, and / or fused to adjacent layers by bead forming pressure roller 59. The use of roller 59 to flatten, flush, and / or fuse the layers substantially eliminates the creation of air trapped between adjacent layers.

[0029] In one aspect, the additive manufacturing apparatus described with respect to FIGS. 1-4 may be configured to perform a 3D printing process to print the plug 80 shown in FIG. 5. In one aspect, the plug 80 may be formed as a single integral part including both the hull 81 and the deck 82. The plug 80 may be formed by printing multiple parts, which are subsequently joined together to form a single part including both the hull 81 and the deck 82. These separate parts may be bonded, fused, or attached in any suitable manner. Whether the plug 80 is formed during a single continuous printing process, or formed by bonding or otherwise joining multiple separate printed parts, the plug 80 has a shape that matches the shape of the final boat, as shown in FIG. 5. The plug 80 may be constructed by an additive manufacturing or 3D printing process, for example, by a horizontal printing process in which the nozzle 51 extends vertically, or a vertical printing process in which the nozzle 51 extends horizontally. When the plug 80 is formed by joining two or more separate parts, each of the parts may be formed by either a horizontal printing process or a vertical printing process. The machine shown in FIGS. 1-4 may form the plug 80 in a single continuous printing operation or in multiple separate printing operations. By forming the plug 80 in two or more parts produced using the CNC machine 1 and in separate printing operations, the plug 80 may have a length or height that is greater than the length of the horizontal work table 27. In some aspects, the plug 80 may be constructed by 3D printing such that at least one first layer forms a portion of the hull portion 81 and at least one second layer forms a portion of the deck portion 82. As will be appreciated, each of the hull portion 81 and deck portion 82 of the plug 80 may include multiple layers of material 53 that are melted to form the integral body of the plug 80 (see FIG. 3). Once the plug 80 is formed, a CNC machine may be used to machine the plug 80 to its final size and shape. The use of a CNC machine allows the 3D printing process to be performed in a repeatable manner that is less dependent on skilled craftsmanship.Once the plug 80 is manufactured (printed, machined, and / or assembled if necessary), it may be mounted to a plug support frame 83 coupled to one or more floor supports 84. When the plug 80 is thus coupled to the one or more floor supports 84, it may be suspended above the floor. In addition, the floor supports 84 allow the plug 80 to be rotated (e.g., about an axis 88) so that the hull 81 or deck 82 faces upward. To form a mold, glass fiber may be applied to the plug 80 (e.g., to at least a portion of the hull 81 and / or at least a portion of the deck 82). Because the plug may be selectively rotated about the axis 88, glass fiber may be applied to the plug 80 positioned at any desired angle, allowing for the selection of a rotational position of the hull 80 that best suits a particular situation or portion of the process to make the mold.

[0030] As shown in the plan view of FIG. 6A and the side view of FIG. 6B, the hull 81 is positioned (rotated and fixed in a first position) so that it faces up. With the hull 81 positioned so that it faces up, a plastic, such as a plastic containing reinforcing fibers (e.g., glass fiber), can be applied to produce a mold for the hull 81 from the printed plug 80. Similarly, as shown in the plan view of FIG. 7A and the side view of FIG. 7B, the plug 80 is rotated (rotated to a second position) so that the deck 82 faces up. With the deck 82 facing up, a plastic material, such as glass fiber, can be applied to produce a mold for the deck 82. The glass fiber material forms a smooth or finished surface (e.g., polished and / or coated surface) for receiving the plug 80 hull 81 and deck 82, thereby reducing or eliminating the need to machine the mold formed by the hull 81 or deck 82. In this manner, a single plug 80 is used to produce molds for both the hull and deck of the boat. Additionally, a single boat plug 80 requires less floor space than two or more separate boat plugs for the hull and deck, thereby reducing costs associated with the plug 80. Also, constructing (e.g., by 3D printing) a single boat plug 80 for both the hull and deck is less expensive than preparing two or more separate plugs, further reducing costs associated with the plug 80. Additionally, the material (e.g., thermoplastic material) used to print the double-sided plug 80 is significantly more durable than materials such as wood, foam, etc. Thus, the plug 80 does not degrade as much as plugs made from traditional materials and can be used to manufacture a significantly larger number of molds. The 3D printing process and subsequent machining is faster than traditional methods, reducing the time required to make the plug 80.

[0031] Features such as the console 85 may also be provided on the deck 82, as shown in Figure 5. In some aspects, it may be desirable to alternatively manufacture one or more features separately from the plug 80, such as features that are difficult to manufacture during the initial printing process. To manufacture a deck plug having all of the desired features, the features, such as the console 85 in Figure 8, are manufactured separately (e.g., by an additive manufacturing process such as 3D printing or another process) and subsequently attached or coupled to the deck.

[0032] From the above detailed description, it will be apparent that several changes, adaptations, and modifications of the present disclosure will be within the realm of one skilled in the art to which the present disclosure pertains. For example, aspects of the present disclosure can be used to manufacture any watercraft or boat of any shape and composition. It is also contemplated that the present disclosure can be used to manufacture other components (e.g., marine products or components, automobile parts, medical devices, machine parts, consumer goods, etc.). All such variations that do not depart from the spirit of the present disclosure are intended to be considered within its scope as defined by the claims.

Claims

1. 1. A method of manufacturing a plug formed by additive manufacturing, comprising the steps of: The plug has a hull portion and a deck portion, Supplying the feedstock to an extruder of an additive manufacturing apparatus; heating the material to form a flowable material; depositing a first layer of the flowable material from a nozzle of the additive manufacturing device to form a portion of a hull portion of the plug; depositing a second layer of the flowable material from a nozzle of the additive manufacturing device to form a portion of a deck portion of the plug; machining the hull section and the deck section using the additive manufacturing device; The deck portion includes a surface that is recessed inward toward the hull portion and a convex portion, wherein at least one of the first layer and the second layer is deposited by a vertical printing process using the horizontally extending nozzles to deposit onto a vertically extending surface.

2. The method of claim 1 , wherein the plug comprises a unitary body including the hull portion and the deck portion.

3. 3. The method of claim 1 or 2, further comprising, after said machining, rotatably securing said plug to at least one support.

4. further comprising: rotating the plug secured to the support to a first position in which the hull portion is positioned above the deck portion; and rotating the plug secured to the support to a second position in which the deck portion is positioned above the hull portion.

5. 5. The method of claim 4, further comprising applying fiberglass material to the hull and deck portions of the plug while the plug is positioned in the first and second positions, respectively.

6. The method of claim 4 , wherein the hull portion includes a first finished surface and the deck portion includes a second finished surface opposite the first finished surface.

7. A system for manufacturing a boat mold, comprising: a plug having a shape that corresponds to the shape of the final boat and made of a thermoplastic material; a support configured to rotatably suspend the plug; an additive manufacturing apparatus for manufacturing the plug; the plug includes a hull portion and a deck portion integrally formed with and opposite the hull portion; The hull portion has a hull surface; The deck portion has a deck surface opposite to the hull surface, The deck portion includes a surface that is recessed inward toward the hull portion and a convex portion, the hull portion and the deck portion are each formed from a thermoplastic material; The additive manufacturing apparatus includes a vertical work table having a surface extending in a vertical direction perpendicular to a horizontal plane, and is configured to perform a vertical printing process in which multiple layers of thermoplastic material are deposited on the surface of the vertical work table from horizontally extending nozzle openings, and is configured to machine the deposited layers of the hull and deck portions that constitute the plug.

8. 8. The system of claim 7, wherein the support rotatably supports the plug, the plug being rotatable to a first position in which the deck surface faces upward and to a second position in which the hull surface faces upward.

9. 9. The system of claim 7 or 8, wherein the additive manufacturing apparatus further comprises a horizontal work table having a horizontally extending surface and configured to perform a horizontal printing process in which a layer of thermoplastic material is deposited onto the surface of the horizontal work table from openings of a vertical nozzle extending in a vertical direction.

10. The system of any one of claims 7 to 9, wherein the plug is a monolithic structure formed by multiple layers of the thermoplastic material deposited by the additive manufacturing device.

11. A method for manufacturing a boat mold, comprising the steps of: Supplying the feedstock to an extruder of an additive manufacturing apparatus; heating the material to form a flowable material; depositing the flowable material from a horizontally oriented opening of a nozzle of the additive manufacturing apparatus in a single continuous printing process to form a plug having a shape corresponding to a shape of a final boat, the plug including a hull portion and a deck portion opposite the hull portion; applying a plastic material to at least one of the hull portion and the deck portion of the plug; and forming a boat mold by allowing the plastic material to harden and removing the hardened plastic material from the plug. The deck section includes a recessed surface that generally conforms to a shape of an inner surface of the hull section, and a convex portion.

12. The method of claim 11 , wherein the plastic material comprises reinforcing fibers.

13. 13. The method of claim 11 or 12, further comprising machining the formed plug prior to applying the plastic material.

14. 13. The method of claim 11 or 12, further comprising rotatably supporting the formed plug prior to applying the plastic material.

15. applying the plastic material to the hull portion while the plug is in a first position where the hull portion is above the deck portion; 15. The method of claim 14, further comprising rotating the plug to a second position in which the deck portion is above the hull portion and applying the plastic material to the deck portion while the plug is in the second position.

16. A method according to any one of claims 11 to 15, wherein a mould for a hull portion of the boat is produced by applying the plastic material to the hull portion, or a mould for a deck portion of the boat is produced by applying the plastic material to the deck portion.

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