Construction of Fishing Vessel Molding with A Case Study of Ship Objects for The Java South Sea Region

In the process of building fiberglass boats (FRP), mold or molding is needed to make the hull and superstructure. Molding can be made of several kinds of main constituent materials including steel, wood, aluminium, HDPE and others. The object of the case study was carried out by collecting data from existing ships at the South Coast of the Java Sea. Molding is the main means in the fabrication process for fiberglass boats. To find out how long the mold or molding can be used, a service life analysis is needed. In terms of current technology, the analysis method uses structural fatigue analysis or fatigue analysis. In the calculations, the design is carried out earlier by conducting modelling simulations. In the fatigue analysis of the molding structure, material data is required to be applied to the molding. This will provide input data at the preprocessing stage in the finite element method. Furthermore, if the lifetime results are known at the age of the mold, then it can be continued with making the fishing boat molding product. So that later it can provide an illustration for shipbuilders that the time or age of the mold can be used for the time that has been designed.


Java South Sea Region Special case
In the process of building fiberglass boats (FRP), mold or molding is needed to make the hull and superstructure.Mold is an indispensable component in the production process of fiberglass boats [1,2,3] In fabricating fiberglass boats, there are two methods of molding, namely negative molding and positive molding.Negative prints produce a smooth inside while positive prints produce a smooth outer surface.The shape of the print refers to the line plan drawn at a scale of 1:1.In making the mold, accuracy is needed so that the ship body formed will be the same as the planned drawing.Molding can be made of several kinds of main constituent materials including: steel, wood, aluminum, HDPE and others.
The object of the case study was carried out by taking data from existing ships at the South Coast of the Java Sea.The condition of the South Java Sea where the sea is very extreme so it is necessary to build a ship with a high wave operational level.The abundance of marine resources in the form of fish is very abundant, so there is a great need to procure traditional fishing boats.In fact, on the south coast of Java, many people use fishing boats made of wood or fiberglass.It is known that the cost of making 1265 (2023) 012003 IOP Publishing doi:10.1088/1755-1315/1265/1/012003 2 fiberglass boats is more affordable than wooden ships.In the future, people will make more and be familiar with fiberglass boats.
Molding is the main means in the fabrication process for fiberglass boats.But they (the fiberglass shipbuilding community on the coast of Java) don't know how much capital they can get back because they don't know the useful life of the molds they make.To find out how long the mold or molding can be used, a lifetime analysis is needed.In terms of current technology, the analysis method using structural fatigue analysis or fatigue analysis is a solution to determine the service life of the die.In the calculations, the design is carried out earlier by conducting modeling simulations.In the fatigue analysis of the molding structure, material data is required to be applied to the molding.This will provide input data at the preprocessing stage in the finite element method.Furthermore, if the lifetime results are known at the age of the mold, then it can be continued with making the fishing boat molding product.So that later it can provide an illustration for shipbuilders made of fiberglass that the time or age of the mold can be used for the time that has been designed.

Detail mold application 1.2.1 Molding
Mold is a very decisive component in the production process of fiberglass boats.There are 2(two) methods for fabricating fiberglass boats, namely negative molding and positive molding.Negative prints produce a smooth inside while positive prints produce a smooth outside surface.The shape of the print refers to the line plan drawn at a scale of 1:1.In making the mold, accuracy is needed so that the body of the ship formed will be the same as the planned drawing.

Lamination
Lamination technology is a technique of combining materials with the help of adhesives, small building materials can be glued together to form component materials as needed.Lamination techniques can also be used to combine raw materials that are not uniform or of various qualities [4] [5].Lamination is done by wet lamination technique according to standard procedures.In this lamination used unidirectional fiber to get good tensile strength according to the results of Munasir's research.In this study it was laminated using fiberglass-making materials (Resin, Woven Roving, Matt, catalyst and pigment).

Method
At this time, the proposer is still at the stage of studying materials relating to literature studies and the stage of making survey forms [6] [7].Where in the literature study studied materials about the process of making ship molds, theory in the application of finite elements, fatigue analysis and mold fabrication process procedures [9][10] [11].So that in this study, it is hoped that further and more in-depth accountable results can be obtained by carrying out the development of the theory obtained from research or the results of previous journal references [8] [12].The form of the flowchart can be shown in the process flowchart as follows:

Material
Some of the main ingredients in multi molds are shown in the form of materials, including: The explanation for each material can be shown as follows: Another term for melamine multiplex is Plywood and plywood [12].This material is the result of gluing (press) of several components of wood sheets with high pressure.In processed wood made from layered meranti.Plywood is a part of a board made of layers of plywood, usually multiples of 3mm, for example 6mm, 9mm, 12mm, 15mm, 18mm.If it is not a multiple of 3, it is usually an error product group.The advantage of using multiplex is that it is strong, more water resistant than particle board and mdf, so it is a material commonly used to make kitchen sets.In multiplexes the possibility of being exposed to termites is small because they are glued so that termites that are not chemically resistant die.The finish or finish used can be melamine, duco, HPL and polyurithane.Wood putty can be used to patch or level wood, making painting easier.This putty is usually applied to raw wood prior to the finishing process.Wood putty, some are actually wood putty, but some are in the form of wood filler.Both are made with different purposes and have slightly different compositional properties as well.Wood filler is a material used to fill in pores or wood fibers.Whereas in wood putty, it is a material used to cover holes or gaps in wood.The basic ingredients of putty are almost the same as the basic ingredients of wood filler, but the putty is made denser and dries faster, while the wood filler is made smoother and only to highlight the fibers in the wood.

Molding result
The following shows the printouts that have been made and placed in the PPNS Non-Metal Workshop.The multimold form that is assembled is a combination of each mold block.This is to simplify the process of sending and storing prints when not in use.

Conclusion
Based on the research that has been done, the process is very important because the flatness of each connection in the joints between the connection blocks must be even and there should be no gaps.This is to produce precise and optimal ship prints.