Raw materials and basic properties
Raw materials are mainly divided into resin and glass fiber two categories; Its structure requires unsaturated polyester resin, and it must have good water resistance and impact resistance. To be suitable for large area operation and good technology, there are many varieties of glass fiber materials, including surface felt, chopped felt, gingered cloth, composite felt cloth, reinforced core material... Let's wait.
1. The rubber shell (gelcoat resin) is used in the appearance of FRP products to improve water resistance and weather resistance, and can keep the color from yellowing for a long time.
2. Laminated resin is used under the rubber shell, generally vinyl resin + phthalic resin.
3. The alkali-free surface felt is used between the gelcoat resin layer and the bearing layer, which is easy to construct and ensures that the surface of the rubber shell will not reveal the fiber traces of the felt cloth.
4. Alkali-free chopped felt includes various types of chopped felt, woven felt and composite felt, which is a good material for contact molding.
5. Alkali-free checkered cloth includes various types of coarse and fine checkered cloth, which can save resin use and increase product strength when forming, in addition to the same characteristics.
6. Alkali-free composite felt cloth includes various types of composite felt cloth, which can increase strength and reduce product weight when forming, in addition to the same characteristics.
7. Reinforced core materials including basa wood, PVC Form and honeycomb board... And so on strengthening materials, can reduce product weight and cost.
Construction method
The general construction methods of FRP yachts are roughly hand paste lamination method and vacuum adsorption method.
Hand paste lamination method is the basic construction method of FRP yachts, most of the best construction method for yachts below 60 feet, construction is not easy to fail, and the appearance of the product is not limited. But if there is no experience in construction the weight of the hull is not easy to control in the best case. As the name suggests, it is the use of manual resin and felt and cloth layer by layer of hand paste out, the required period is relatively long. Hull, deck, flybridge and yacht all FRP fittings can use this construction method.
Vacuum adsorption method is a relatively new process in recent years, generally used for the construction of fast ships above 60 feet. The construction method is to lay the glass fiber layer on the mold, lay the catheter and some auxiliary equipment, use vacuum bag and sealant sealing, and then vacuum the glass fiber layer, and then import the resin molding, is a very effective molding method. And save labor and time, light product weight, low porosity, resin usage is also less, strength increased and so on. However, there are also many one-time auxiliary materials required, and the comprehensive cost calculation is comparable to the hand paste lamination method, and it is certain that the weight of the ship will be relatively light. This method of construction has not been used for many years, and its evaluation in the United States yacht industry is still controversial.
Common fiberglass problems on yachts
Common FRP problems include: cracking of the rubber shell at the structural joints, leakage and water seepage at the joints/openings, foaming of the rubber shell on the deck surface of the FRP hull, or black spots, bubbling and cracking of the stop slide on the deck, leakage of the bottom of the ship, scratches and cracks caused by collision during use. And the surface of the plastic shell color change, color difference...... . The cause may be negligence in manufacturing, or abnormal conditions caused by improper use of FRP.
The cause of the problem and the treatment method
Problems often occur on the surface of FRP and the reasons and different treatment methods are described as follows:
1. Color change, foaming and black spots on the surface of the rubber shell:
Due to the instability of the ratio of curing agents used in different times of climate change during local repair construction, or the color difference of different batches of rubber shells will cause the color change of the external rubber shell in the future (dark color difference, yellow), especially on the dark rubber shell.
Failure to completely remove small bubbles and dust particles during deposition will cause bubbling and black spots on the external shell in the future.
Treatment method:
a. Chromatic aberration; Polish off the surface of the rubber shell layer, re-apply the same type of rubber shell, water grinding to #1000 or above sandpaper and then polishing and waxing. During production and repair, the amount of curing agent added should be controlled according to the manufacturer's suggestion.
b. Blistering/black spots; Chisel away the foam/black spots where the rubber shell layer, re-apply the same type of rubber shell, water grinding to #1000 or above sandpaper and then polishing and waxing finished.
c. If deep bubbling or black spots; To dig to the end, and then use the broken felt and laminated resin to fill the sunken part, to be cured and then re-coated with the same type of rubber shell, water grinding to #1000 or above sandpaper and then polishing and waxing.
2. Cracking at the joint of hull and deck:
Most accidental collisions occur when the gunwale (hull and deck) joint cracks.
Treatment method:
a. Locally small collisions; Remove the side fender strip to repair the FRP, re-fix it with structural glue and bolts, and then reinforce/repair it.
b. Collisions with large areas; Please contact the dealer to arrange professional repair.
3. Cracking of rubber shell on the surface of hull, deck, flybridge and FRP parts:
Most of them occur at the joint between the stairs, Wet Bar and other single glass fiber reinforced plastic fittings and the main body of the deck, because it is the combination of two glass fiber reinforced plastic parts, the concave and convex corner parts are easy to crack at the surface rubber shell due to long-term use.
Treatment method:
Remove the excessively thick surface rubber shell layer, reinforce it with felt cloth and layer resin, re-coat the same type of rubber shell after curing, water grind to #1000 or above sandpaper and then finish polishing and waxing.
4. Water on deck surface:
Local water accumulation due to poor drainage of the deck surface stopper or teak deck.
The solution:
A. Local water near the edge can be added a drain.
b. The drainage slope of the surface floor should be rearranged for the larger water.
5. The bubbling of the stop plate on the deck and the cracking water of the floor at the joint with the wall:
Board bubbling is easy to occur after long-term use. The cracking water at the joint is generally caused by poor construction.
The solution:
a. Cut out the chiseled stop plate and replace it with a new stop plate with the same pattern. Pay attention to the continuity of the pattern when repairing.
b. Cracking water at the joint; Chisel the cracked water part and repair it again.
6. Leakage of large window openings and FRP walls:
The general cause is leakage caused by the deformation of the large window after impact or poor construction.
The solution:
a. Large window deformation leakage; Replace with a new large window of the same model - ask your dealer to arrange for professional treatment.
(b) General leakage; First, remove the wooden decorative batten in the cabin, re-glue and reinforce, and then install the decorative batten.
7. Leakage of porthole openings and FRP hulls:
Leakage due to poor construction.
The solution:
First, remove the wooden decorative batten in the cabin, re-glue and reinforce, and then install the decorative batten.
8. Leakage of equipment installation openings and FRP body/floor:
Due to construction negligence, leakage often occurs at the openings of various equipment installations involving hull/deck joints, such as engine and propeller shaft system inlet and outlet, generator inlet and outlet, bow/stern thruster installation, associated oil/circuit/drainage lines, stabilizer fins... And so on through the ship deck parts are prone to occur.
The solution:
The above work is in the field of professional technology, with safety considerations. - Please contact the dealer to arrange professional treatment.
9. Windlass installation/opening water leakage:
The windlass is above the hawse bin, and poor installation causes water leakage into the hawse bin, which may seep into the motor of the windlass and cause the windlass to malfunction. Or the windlass opening drainage is poor, resulting in water or flow into the hawse.
The solution:
a. windlass installation leakage; After reinstalling the windlass and gluing, the bolts are fixed.
b. Water leakage at the windlass opening; Check the drainage system and strengthen the drainage slope.
10. Fine leakage on the bottom glass steel surface (Osmosis) :
Due to the poor construction of the bottom of the hull, the yacht has been used for a few years after the partial area or most of the area of the bottom of the small leakage occurred, such as long-term penetration will cause the weight of the hull, slow down the cruise speed and cause early aging of the FRP hull structure.
The solution:
Lift the yacht to the dock or dock for a complete overhaul below the fibreglass waterline. - Please contact the dealer to arrange professional treatment.
11. Leakage at the opening of the ship bottom:
The hull below the waterline has many intakes and drains, which can also leak if construction is negligent or improperly used.
The solution:
Lift the yacht to the dock or dock for a complete overhaul below the fibreglass waterline. - Please contact the dealer to arrange professional treatment.
12. Scratches and cracking of FRP exterior during accidental collision:
The solution:
a. Small local scratches; If the scratch does not hurt the FRP part, the surface of the rubber shell is removed first, and the sunken place is repaired with soil, and the rubber shell of the same type is re-coated, and the water grinding to #1000 or above sandpaper is then polished and waxed.
b. If the scratch has damaged the FRP part; Or first remove the surface of the rubber shell, and then use the glass fiber felt and laminated resin to repair the sunken place, after the curing is completed, re-apply the same type of rubber shell, water grinding to #1000 or above sandpaper and then polishing and waxing.
c. Cracking occurs on impact;
This is a serious crash resulting in cracking, which is a safety concern. - Please find the dealer in time to arrange professional treatment.
Easy maintenance for FRP yachts
• Daily cleaning and care - remove accumulated seawater and dirt on the surface, and keep dry at all times.
• Regular waxing and polishing - keep the surface of the FRP bright while protecting the rubber shell.
• Treat scratches promptly - avoid leaks.
• Avoid prolonged sun exposure - Cover the FRP instrument panel on the flybridge and the driver's chair/entire boat with a canvas cover/boat cover when not in use, and pack the yacht ashore in winter.
• Careful handling of the correct mooring - use the anti-collision ball when the boat is docked... Avoid direct contact with shore stones, concrete structures, metal parts... Let's wait.
• Manual - Careful reading of the owner's manual is the most effective way to maintain your yacht.
