How to make a boat with fiberglass cloth?

Date:20-09-26

Process flow
1. General outline
Making wood type → wood type treatment → du mold manufacturing → mold treatment → release agent → gel coat → resin (putty) → felt dao/cloth/composite felt (multilayer board/balsa) → curing → assembling frame (reinforcement) )→ demoulding→ trimming and assembly
2. Process
2.1 Making wood type
2.1.1 Upper body
2.1.1.1 Construction of the slipway
According to the ship type and main parameters (Loa, B, D), channel steel is used to construct the berth, with two vertical channels extending at each end, and the channel steels are uniformly outwards. Depending on the size (weight) of the hull in the middle of the berth, beams or longitudinal girders are added . Fix the wooden square on the berth, use the level to use the electric planer (hand planer),
1.1.1.1 Make the reference plane steel frame, pay attention to the channel steel facing outward
1.1 Draw a reference line
1. Mold making
(1) Method:
① Lofting according to the rib position → centering the center line, making and assembling a sample plate (leave a certain height underneath when assembling to facilitate exhaust) → paving the hollow space → putting putty (gypsum or other putty, and smoothing with a shoulder ruler → polishing with water sandpaper → Spray paint (or gel coat, generally spray paint is fine, gel coat is more expensive) → release agent → mold gel coat (more expensive than product gel coat) → mold resin (small deformation. low shrinkage) → felt/cloth/composite felt →curing →installation of support plate → demoulding → trimming
②Use his man-made boat/component as a mold, for example:
a. The printed glass processing mold can be used to make a non-slip board;
b. Asbestos tiles are made by the method of film → felt/cloth → film (do not generate bubbles) → modeling → uncovering the film.
2. Release agent
(1) Type:
①One-time wax is floor wax (large amount) + one-time release agent is suitable for new molds. Apply more wax and less release agent. After release, there is a layer of protective mold on the outer surface of the hull; after releasing the film, apply it again Wax (small amount) + one-time release agent;
②One-time wax (large quantities) + multiple release agents are suitable for mass production of old molds, and the gel coat can be sprayed again after cleaning with a clean rag each time the mold is released. Do not dip it in water, otherwise the release agent will be wasted many times, and waxing must be repeated;
③One-time wax (large amount) + multiple waxes are suitable for mass production of old molds, and the gel coat can be sprayed again after wiping with a clean rag every demoulding. If it gets wet, wipe it dry with a rag and then wax it twice, no need to wax once. In fact, it is possible to remove the film only by waxing several times, but the price is more expensive than that of waxing once.

 

(2) Comparison:
①The safest demolding; ②It is more convenient than ③can demolding, but the price is more expensive; ②and ③do not protect the mold, it will damage the mold, and the mold needs to be repaired regularly (see 10-(1)- ② for repairing methods) ).
3. Gel coat
(1) Blending: gel coat + curing agent (methyl ethyl ketone peroxide, also known as "white formula", curing agent accounts for 1-4% of the gel coat weight)
(2) Operation:
①Spray molds with large structures with spray guns, and use brushes for small molds. When spraying with a spray gun, the gel coat is mixed with the curing agent, and the machine is automatically configured;
②The color part of the hull body is first blocked by color separation paper, then the main color part is sprayed, and then the color separation paper is removed to block the main color part and the color is sprayed.
4. Resin
(1) Blending: resin (unsaturated polyester resin) + accelerator (also known as "red formula", to promote curing) + white formula (accelerator and curing agent are generally 1-4% of the weight of the resin)
(2) Function: Cementation and saturation.
6. Resin putty
(1) Blending: resin + red formula + talcum powder + white formula
(2) Function:
① Filling the corners or gaps with putty can play a transitional effect. Please pay attention to wipe it evenly with a resin-soaked brush after finishing the resin putty;
②Can fix multi-layer boards and cork in complex structures;
③It can be used as materials for repairing ships.
(3) Disadvantages: It is brittle after curing and cannot be used to stick smooth surfaces.
(4) White carbon black (silica powder) can also be used to mix putty (with gel coat or resin), with better quality and smoother (can be used to repair ships).
5. Felt/cloth/composite felt
(1) Difference:
①There are various types of felt/cloth/composite felt, and the degree of laying is from easy to difficult;
②The surface felt is thinner than other felts. It is the first layer of felt after spraying the gel coat, and then other felts, cloths, etc.;
③The needle-made composite felt is equivalent to the combination of cloth and felt, one side is felt and the other side is cloth (such as 1050);
④Spray yarn can replace composite felt, but the resin content is large when the machine is sprayed, which is easy to waste;
⑤m stands for surface felt, M stands for felt, R stands for cloth, and B stands for balsa wood.
(2) Operation:
①Use resin putty for transition where it is not easy to lay up;
②The complex part of the mold structure can be replaced by a combination of cloth and felt to reduce the difficulty of laying (such as the first part of the upper body);
③Use scissors to cut the felt/cloth/composite felt at this side to facilitate laying;
④After positioning the felt/cloth/composite felt, brush the resin;
⑤The large twister is used for smooth parts that are easy to handle, and the small twister can handle complex parts with many edges and corners. To prevent bubbles from appearing. If the air bubble has been solidified, use a blade to cut it off and fill it;
⑥Each layer of felt/cloth/composite felt should eat through the resin, and it should be decided to brush several layers of felt (cloth/composite felt) at a time according to the situation. Generally, the layering of workpieces with a thickness of more than 5mm should be divided into two. For example, 300 felts can be coated with 2 layers at the same time and then brushed with resin, and a layer of 300 felt and a layer of 1050 composite felt can also be used;
⑦If there are burrs at the border of cloth/composite felt, it can be smoothed with small pieces/strip felt;
⑧After each process is completed, the felt side should be facing outwards. It is best to put the felt side facing inward when laying multi-layer composite felt (beautiful); sometimes, an angle grinder can be used to polish the cured felt, which is beneficial to the next accumulation. Convenience of layers.
6. Multilayer board/cork
(1) Function: Increase the thickness of the hull to meet the requirements of increasing strength.
(2) Multilayer board construction procedure:
①Before construction, the multi-layer board should be opened (breathable) and coated with resin and dried (saturated treatment);
②Apply resin putty to the place to be laid and treat it evenly, and make the rough surface of the multilayer board face inward when laying;
③After laying the board, use a hammer to fix it, fill the opening with putty and fill in the transition around the board;
④ After curing, use a grinding wheel to smooth the board and its periphery.
(3) Cork construction procedure:
①Before construction, use putty to fill the corners and gaps;
② Bond the balsa wood with felt brushed with resin, and fill in the bumps in advance with putty (for the stern of the hull).
7. Curing
Sign: The resin can be cured to the extent that it can be used for the next process.
8. Skeleton (rib)
(1) Type: multilayer board or foam
(2) Comparison: Foam is easier to shape than wooden skeleton
(2) Multilayer board skeleton:
①To install the skeleton, first locate the skeleton by the locator;
② Cross combination of wooden skeletons (long skeletons can be lapped, if the skeletons are curved, they can be staggered on both sides of the board edge to facilitate bending), fixed with felt/cloth/composite felt.
(3) Foam bars:
① Draw the center line on the hull, and then set the edge line;
②The foam ribs are fixed with a plastic glue stick heated to a liquid state, the ends are thinned, the corners are treated smoothly and then brushed with resin (saturation effect), and then covered with felt/cloth/composite felt after a certain period of time;
③The foam ribs only play a role in shaping and can be broken if necessary;
④ The outer surface of the stiffened ship sometimes seems to have marks;
⑤The foam can be combined 1:1 by weight of A and B foaming agents. Agent A is yellow, and agent B is brown with a large specific gravity. Lay newspaper in the mold first, then pour the mixed A and B agents quickly, and cover with a perforated lid (to prevent the lid from bulging) and wait for a while to form.
9. Demoulding
(1) Air hole: The position of the air hole should be selected in the opening part of the hull and made into a horn shape.
(2) Method: The gas injection method is more commonly used, if it is not easy to demold, the water injection method can be used.