Many people have a question after reading ‘Ten Year Review of Composite Materials’: AFP automatic silk laying HP-RTM、 With the continuous popularization of thermoplastic molding and the gradual replacement of manual labor by automated production lines, is hand glued fiberglass almost being eliminated?
There is a very practical judgment in the industry: ✅ Large quantities of standardized products will gradually be phased out of the market; ✅ Small batch, irregular, oversized, on-site customization, and tooling trial production scenarios make it difficult for machines to replace hand paste.
1、 Why can’t machines replace manual dexterity?
The core advantages of hand lay up molding include low mold investment, strong flexibility, adaptability to any complex surface, support for local thickening, embedded parts, and even direct on-site construction. For single piece, small batch, and oversized irregular components, the cost of automated mold opening is extremely high, the equipment utilization rate is low, and it is completely uneconomical. Here are typical engineering cases that still heavily rely on manual labor:
💙🚤 Case 1: More than 90% of domestic fishing boats, sightseeing boats, rescue patrol boats, and customized sea fishing boats, including small and medium-sized fiberglass vessels and leisure fishing boats, use hand laid structures for their hulls, decks, and cabins. Typical project: A 38 meter fiberglass leisure fishing boat with a hand laid horizontal skeleton structure. By relying on hand laid flexible layers, complex curved surfaces can be formed as a whole, and local thickening and impact resistance can be applied to positions such as the bow and keel of the ship, while also considering resistance to seawater corrosion. There are multiple ship types, large single ship volumes, high degree of customization, and high cost of automated molds. Hand pasting is the most cost-effective solution.
💙🏭 Case 2: Non standard equipment for chemical anti-corrosion, on-site lining engineering for petrochemical, power plant, and sewage treatment fields, irregular towers, tank linings, variable diameter pipelines, desulfurization flues, and acid alkali pool anti-corrosion mostly rely on manual on-site construction. Typical projects: FRP anti-corrosion lining for refining base, FRP chimney renovation for large incinerator. The equipment interface is complex and the working conditions are varied, requiring manual reinforcement of internal and external corners, local thickening, and automated processes such as winding and stretching that cannot be constructed on-site according to the shape.
💙🌬️ Case 3: Trial production molds and tooling for wind power and low altitude equipment, prototype molds for wind power large blades, eVTOL manned spacecraft tooling, large unmanned aerial vehicle test pieces, and surface verification molds, commonly using hand lay up technology. Typical applications: Thick layer reinforcement of wind turbine blade roots, and flipping of low altitude aircraft prototypes. New products have fast iteration, diverse models, and extremely small batch sizes. Hand pasting can quickly complete prototype layering and surface modification, making it a prerequisite for high-end composite material research and development.
💙🏗️ Case 4: Customized components for infrastructure, cultural and tourism industries, urban sculptures, cultural and tourism shapes, architectural curved decorative parts, swimming pool FRP waterproof surface layer, bridge anti-corrosion reinforcement, all belong to non-standard shaped parts and have no standardized mass production value. Hand pasted integrated molding, no splicing gaps, extremely high degree of freedom in shaping.
💙🛠️ Case 5: On site repair, emergency reinforcement engineering, repair of fiberglass fishing boats after typhoons, renovation of aging inner lining of storage tanks, and repair of outdoor anti-corrosion components. The size of the old components is irregular, and it is difficult to match the prefabricated parts. Only by hand pasting can they be repaired on site according to the shape and quickly restore the structural performance.
✅ In summary, machines produce “standardized batch products” and hand pasted products produce “non-standard, oversized, on-site, trial production”. The two complement each other, not replace each other.
2、 Shortcomings that cannot be avoided by hand pasting
Although some scenarios cannot be replaced, the inherent performance limit of the hand stick determines that it cannot enter the high-end main load-bearing mass production tracks such as aviation and hydrogen energy.
- Low performance upper limit
Artificial roller exhaust has a fiber content of only 35% -45%, a high porosity, and weaker mechanical properties, fatigue resistance, and batch consistency compared to vacuum infusion, prepreg, and molding processes. - The pressure of environmental control is enormous
Traditional open hand pasted styrene with unorganized scaling up. Environmental policies are tightening, and small workshops without waste gas collection facilities are continuing to shut down. - Significant bottleneck in production efficiency
Highly dependent on manual labor, not suitable for standardized mass production of tens of thousands of items. - Quality control highly relies on operator experience
The thickness of the layer, resin content, and exhaust effect vary from person to person, with large batch fluctuations, making it difficult to meet the strict material traceability requirements of aviation and hydrogen energy.
3、 Industry pattern: Thoroughly clearing the low-end market, refining the manual retention
In the past decade, the hand paste industry has undergone drastic differentiation, forming a clear bipolar pattern.
🟠 ❌ The extensive hand pasted ordinary water tank, simple daylighting board, low-priced universal shell, and low-end anti-corrosion parts that are being phased out. Large quantities, low technology, no process documents, no environmental protection facilities, pure low-priced internal rolling, continuously replaced by molding, extrusion, and vacuum infusion.
🟢 ✅ Long term stable and profitable customized customized non-standard large items, ship hulls, chemical special anti-corrosion, on-site renovation and repair, high-end trial production tooling, and irregular cultural and tourism components. Core thresholds: environmental compliance, process standardization, on-site technical service capabilities, higher gross profit, and less competitive pressure.
The future is not about the disappearance of handmade crafts, but about the continuous clearance of extensive handmade workshops.
4、 Ten year upgrade of handmade crafts: no longer a traditional old workshop model
Many people’s impression of hand pasting is still simply brushing resin and laying fiberglass cloth, relying on the hands of experienced craftsmen. The manual dexterity of regular factories has completed four major upgrades:
✅ Upgrade and promote low styrene, low VOC unsaturated resins, vinyl esters, and epoxy systems to reduce workshop odors and meet environmental emission requirements.
✅ The workshop has been upgraded to an open workstation and transformed into a closed negative pressure manual pasting room with an exhaust gas treatment system, with certified and compliant production.
✅ Technological upgrading promotes the use of hand lay up and vacuum bag pressing composite technology. After manual layering, negative pressure compaction is applied to increase fiber content, reduce pore defects, and narrow the performance gap with closed mold technology.
✅ Standardization upgrade establishes a system for layer recording, thickness control, curing monitoring, and sample retention, transforming the experience of experienced craftsmen into auditable and traceable standardized processes to meet industrial customer acceptance. - The future positioning of Hand Paste is very clear
- Positioning: Flexible bottom covering process, no longer the main production force
The automation closed mold process focuses on large-scale high-performance components for aviation, low altitude, hydrogen energy, wind power, and automobiles; Hand held six essential scenarios: non-standard, oversized, irregular, on-site, trial production, and repair. - The industry continues to reduce low-end internal competition
Small workshops without environmental protection, standards, and low price competition continue to withdraw; Compliant fine chemical plants occupy the high value-added customization market. - Clear application boundaries, each performing their own duties
High end main load-bearing components, gradually phased out by hand; Tooling molds, non main load-bearing irregular parts, anti-corrosion engineering, ship customization, on-site repair, hand lay up cannot be replaced for a long time.
💡 one-sentence summary
The backwardness lies in the extensive manual pasting, not the manual pasting process itself. Standardization, compliance, refinement, and scenario based manual dexterity still have long-term, stable, and irreplaceable industrial value.