Restoration process for ancient building flying rafter head and continuous eave tile opening

Abstract

An ancient building flying rafter head and continuous eave tile mouth repairing process, characterized in that, comprising the following steps: 1, the wood structure is thoroughly cleaned and repaired; 2, ground layer construction; 3, color drawing; 4, the outer side of the flying rafter head and the continuous eave tile mouth is sealed by using 304 stainless steel plate; 5, the gap between the water drop and the tile mouth is sealed by using weather-resistant glue; the weather-resistant glue is prepared from raw materials including VAE emulsion, Portland cement, pigment, polypropylene fiber, silica ash and latex powder; wherein, the 304 stainless steel plate is coated with an epoxy fluorocarbon composite coating, and the coating has a three-layer structure, which is composed of a base layer, an intermediate layer and a covering layer.

Description

Technical Field

[0001] This invention belongs to the field of ancient building technology, specifically relating to a repair process for the flying rafter ends and eaves tile openings of ancient buildings. Background Technology

[0002] In traditional wooden buildings (especially those with hip, gable, or hard gable roofs), the flying rafter ends and eaves tile joints are key components of the eaves, jointly providing support, waterproofing, and decoration for the roof's overhang. The eaves tile joints are horizontal wooden strips fixed above the flying rafter ends, connecting the rafters to the roof tiles. As crucial elements of the ancient building's roof structure, the flying rafter ends and eaves tile joints are constantly exposed to the outdoor environment, suffering from the continuous effects of natural climate and the erosion of time. Especially in rainy areas, the flying rafter ends and eaves tile joints are more susceptible to rainwater erosion, leading to problems such as paint peeling and wooden structure decay. These defects significantly impact the structural stability and aesthetic appearance of the ancient buildings.

[0003] Rainwater plays a crucial role in the erosion of the eaves and roof tiles of ancient buildings. This rainwater carries not only acidic substances but also a large number of microorganisms, all of which work together to cause significant corrosion to the wooden structural components. Over time, cracks, deformation, and decay appear on the wood surface, severely affecting its integrity and aesthetics. Furthermore, the scouring action of rainwater strips away the oil coating on the surface of the wooden components. This coating, originally intended to protect the wood from environmental damage, significantly reduces the wood's protective effectiveness, thus accelerating the decay process. Wooden structural components exposed to rainwater erosion for extended periods gradually weaken in strength and stability, potentially leading to complete roof structure failure and threatening the safety and lifespan of the entire building. Therefore, preventing rainwater erosion is a vital and indispensable aspect of the protection and maintenance of ancient buildings.

[0004] In ancient architecture, the surface of wooden structures is typically coated with a ground coat of oil, its primary function being to provide protection against weathering from the natural environment. However, due to variations in the quality of the oiling materials and differences in construction techniques, coupled with prolonged exposure to natural weathering, such as the effects of wind, sunlight, and rain, the oiling layer often peels and cracks. Peeling of the oiling layer not only weakens its protective function on the wooden structure but also negatively impacts the building's aesthetic value. Furthermore, damage to the oiling layer exposes the wooden surface, increasing its risk of rainwater intrusion and microbial attack. Wooden components in ancient buildings, exposed to the outdoors for extended periods, are highly susceptible to decay due to rainwater erosion and oiling layer failure. Decaying wooden components not only experience reduced strength but also affect the overall stability and aesthetics of the ancient building. The surface of decaying wood develops cracks, dents, and holes, and in severe cases, can even lead to breakage and detachment of the wooden components. Moreover, decaying wooden components become a breeding ground for microorganisms, further accelerating the decay process.

[0005] In addition, compared with the overall shape of modern buildings, ancient buildings have a lot of gaps in parts such as the eaves and the gaps between the drip edge and the tile opening. Rainwater seepage can easily cause the wooden structure to rot from the inside. The mortar, putty, and blood putty used in traditional repair techniques are susceptible to biological erosion, have insufficient crack resistance, and have poor water resistance and weather resistance.

[0006] In general, the restoration process for the flying rafters and eaves tiles of ancient buildings faces challenges in restoring their original appearance. These challenges include poor adhesion between the newly coated oil layer and the original wooden structure, peeling and cracking due to long-term rain erosion and natural weathering, and the susceptibility of the joint filler to biological attack, insufficient crack resistance, and poor water and weather resistance. To address these issues, the inventors, in collaboration with a university chemistry laboratory, conducted a comprehensive improvement to the restoration process for flying rafters and eaves tiles, along with the protective materials used. This resulted in a rapid restoration process that provides excellent waterproofing, weather resistance, and crack resistance for the flying rafters and eaves tiles of ancient buildings. Summary of the Invention

[0007] This invention relates to a repair process for the flying rafter ends and eaves tile openings of ancient buildings, characterized by the following steps: (1) thoroughly cleaning and repairing the wooden structure; (2) constructing the ground layer; (3) painting; (4) using stainless steel plates to enclose the outer side of the flying rafter ends and eaves tile openings; (5) sealing the gap between the drip edge and the tile opening with weather-resistant adhesive.

[0008] This weather-resistant adhesive is made from raw materials including VAE emulsion, silicate cement, pigment, polypropylene fiber, silica fume, and latex powder.

[0009] The stainless steel plate is preferably 304# stainless steel plate, which is coated with an epoxy fluorocarbon composite coating. This coating has a three-layer structure, consisting of a base layer, an intermediate layer, and a cover layer. The base layer is made of an epoxy resin-type primer containing epoxy resin, epoxy modified filler, and isocyanate curing agent. The particle size of the modified filler is 1-40μm, and the coating thickness is 60-80μm. The intermediate layer is made of a composite two-component intermediate paint containing epoxy resin, fluorocarbon resin, polyamide resin, and aliphatic polyamine. The cover layer is prepared by a two-component fluorocarbon topcoat.

[0010] The facade of the tile opening is covered with a 1-3mm thick stainless steel plate and fixed with stainless steel self-tapping screws;

[0011] The eaves section is also covered with 1-3mm thick stainless steel plates. The top of the eaves is covered with tile openings, and the bottom is fixed to the roof board with stainless steel self-tapping screws. Each rafter section uses 1-3 self-tapping screws.

[0012] The rafter section is encased in 1-1.4mm thick stainless steel plate, and the rafter sides are welded with nail lugs and fixed to the sheath with stainless steel self-tapping screws.

[0013] Among them, the base of the scaffold and both sides of the rafters were sealed with red weather-resistant sealant;

[0014] In the above scheme, the stainless steel plate is preferably 304# stainless steel plate, and the stainless steel self-tapping screw is preferably 304# stainless steel self-tapping screw.

[0015] The cleaning process involves removing surface dirt, moss, and decayed parts to reveal the wood's original color. The repair process includes filling and reinforcing cracks, dents, and holes in the wood structure to ensure its integrity and stability.

[0016] As the base layer for wood finishing, the application of the ground coat requires meticulousness and patience to ensure a smooth surface and strong adhesion. The painted decoration, applied over the ground coat, is typically created using traditional Chinese painting techniques. The selection of patterns and colors for the painted decoration must be based on the historical background and stylistic characteristics of the ancient building, aiming to restore its original aesthetic value and artistic expression.

[0017] Stainless steel sheets can be replaced with aluminum.

[0018] The present invention also relates to a weather-resistant adhesive, which is prepared from raw material components comprising the following parts by weight: 30-40 parts of VAE emulsion, 40-50 parts of silicate cement, 10-20 parts of quartz sand, 5-10 parts of heavy calcium carbonate powder, 15-25 parts of pigment, 0.1-0.3 parts of polypropylene fiber, 2-4 parts of silica fume, 1-3 parts of latex powder, additives, and appropriate amount of water.

[0019] The additives include 0.2-0.5 parts dispersant, 0.1-0.3 parts defoamer, 1-2 parts film-forming aid, 0.1-0.2 parts preservative, and / or 1-3 parts silane hydrophobic agent.

[0020] Furthermore, the pigments are iron oxide red, iron oxide yellow, chromium oxide green, or stable phthalocyanine blue.

[0021] Furthermore, the weather-resistant adhesive is red, and the pigment is iron oxide red.

[0022] Furthermore, the VAE emulsion has a solid content of 50-55%.

[0023] The present invention also relates to an epoxy fluorocarbon composite coating having a three-layer structure, consisting of a base layer, an intermediate layer and a masking layer, wherein (1) the base layer is made of an epoxy resin primer, the primer comprising component A and component B, in parts by mass, wherein component A comprises: 50-60 parts of epoxy resin, 5-15 parts of modified filler, 1-10 parts of additives, and solvent; component B comprises: 5-15 parts of isocyanate curing agent; wherein the modified filler is obtained by modifying silica with an epoxy functional silane coupling agent. The modified filler has a particle size of 1-40 μm, wherein the weight ratio of particle size (30-40) μm: (10-30) μm: (1-10) μm is (2-4): (0.5-1.5): (0.5-1.5), and the coating thickness is 60-80 μm; (2) The intermediate layer is made of a composite two-component intermediate paint, containing component A and component B. Component A contains the following components by mass: 30-40 parts of epoxy resin, 20-25 parts of fluorocarbon resin, and 0.5-1.5 parts of silane coupling agent KH-560. Component B includes: 5-10 parts of curing agent, wherein the curing agent includes polyamide resin and aliphatic polyamine, and the coating thickness is 40-60 μm; (3) The covering layer is prepared by a two-component fluorocarbon topcoat, and the coating thickness is 60-80 μm;

[0024] Furthermore, the base layer is made of an epoxy resin type primer, which includes component A and component B. Component A includes the following components by weight: 50-60 parts epoxy resin, 5-15 parts modified filler, 1-10 parts additives, and 10-30 parts solvent. Component B includes: 5-15 parts isocyanate curing agent and solvent.

[0025] The weight ratio of component A to component B is 10:(0.5-1.5);

[0026] The modified filler is epoxy-modified silica, which is obtained by modifying silica with an epoxy-functionalized silane coupling agent. The epoxy-functionalized silane coupling agent is selected from at least one of γ-glycidoxypropyltrimethoxysilane, 2-(3-4-epoxycyclohexyl)ethyltrimethoxysilane, (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane.

[0027] The additives include: dispersant: 1.4-2.6 parts, defoamer: 0.2-0.3 parts, leveling agent: 0.2-0.3 parts, anti-sagging agent: 2.0-3.0 parts, and silane coupling agent: 0.5-1.0 parts;

[0028] The epoxy resin is a glycidyl ether epoxy resin, and more specifically, at least one of E-3, E-42, E-44, E-20, and E-51.

[0029] The solvent includes at least one of propylene glycol methyl ether, propylene glycol methyl ether acetate, methyl isobutyl ketone, xylene, methyl ethyl ketone, and methyl ethyl ketone, with a more preferred solvent being propylene glycol methyl ether acetate and methyl ethyl ketone in a mass ratio of (2-4):1.

[0030] Curing agent: polyisocyanate, specifically at least one of isophorone diisocyanate, adduct of TDI and trimethylolpropane, adduct of HDI and trimethylolpropane, trimethylhexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.

[0031] Polyisocyanate curing agents can also be used as sealants to seal components A and B, thereby mixing them to form a single-component coating. The sealant can be at least one of methyl ethyl ketone oxime, cyclohexane oxime, phenol, p-tert-butylphenol, cresol, ethyl acetoacetate, and methyl acetoacetate.

[0032] The solvent is at least one of butyl acetate, propylene glycol methyl ether acetate, and methyl isobutyl ketone.

[0033] The curing agent should not contain too much isocyanate. If too much isocyanate is used, the cross-linking density will be high after curing with polyisocyanate, but the adhesion to the metal will be low, and it will be easy to peel off when bent.

[0034] (2) Intermediate layer, the intermediate layer is made of composite two-component intermediate paint, the intermediate paint contains component A and component B, component A contains the following components by weight: 30-40 parts epoxy resin, 20-25 parts fluorocarbon resin, 10-30 parts inorganic filler, 0.5-1.5 parts silane coupling agent KH-560, 0.3-0.5 parts dispersant, 0.2-0.3 parts defoamer, and 10-30 parts solvent, component B includes: 6-15 parts curing agent.

[0035] The curing agent can be 5-10 parts of polyamide resin and 1-3 parts of aliphatic polyamine; component B may optionally contain 0.1-0.3 parts of accelerator and / or an appropriate amount of solvent.

[0036] The polyamide resin can be Aradur 450, and the aliphatic polyamine can be at least one of triethylenetetramine (TETA), polyether diamine (D230, D400), and polyether triamine (T403). As a curing agent, the polyamide resin can improve the toughness of the intermediate layer, and when used in conjunction with aliphatic polyamines, it enhances the rapid crosslinking and curing ability of the epoxy resin.

[0037] The solvent in component A includes at least one of methyl ethyl ketone, xylene, and propylene glycol methyl ether; the curing agent can be a polyamide resin, such as Aradur 450.

[0038] The inorganic filler can be rutile titanium dioxide, mica powder, calcium carbonate, or talc powder, with a specific weight ratio of (10-14):(2-6):(2-6):(2-6). Among them, titanium dioxide enhances hiding power and weather resistance, mica powder improves impermeability, and calcium carbonate reduces coating costs.

[0039] The silane coupling agent KH-560 improves the compatibility of epoxy resin and fluorocarbon resin, and also enhances the adhesion between the intermediate layer and the base layer and the cover layer.

[0040] The epoxy resin is one or a combination of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenolic glycidyl ether, and aliphatic glycidyl ether. The amount of fluorocarbon resin used should not be too high, as this will lead to a decrease in the compatibility between the fluorocarbon resin and the epoxy resin.

[0041] (3) Covering layer, the covering layer is prepared from a two-component fluorocarbon topcoat, the topcoat comprising component A and component B, component A comprising the following components by mass: FEVE fluorocarbon resin: 45.0-65.0 parts, dispersant: 1.4-2.0 parts, expanded vermiculite 10-15 parts, inorganic filler: 5.0-10.0 parts, inorganic pigment: 8.0-12.0 parts, defoamer: 0.2-0.3 parts, leveling agent: 0.2-0.3 parts, matting agent: 2.0-5.0 parts, solvent 2-20 parts; component B is hexamethylene diisocyanate trimer 8-15 parts.

[0042] Furthermore, the expanded vermiculite is 80-120 mesh, the inorganic fillers are rutile titanium dioxide, heavy calcium carbonate, and talc; the inorganic pigments are iron oxide red and iron oxide black; the coating thickness is 60-80 μm; and the solvents include butyl acetate, propylene glycol methyl ether acetate, and methyl isobutyl ketone.

[0043] Technical effect

[0044] (1) In terms of durability, the use of 304# stainless steel plates for encapsulation significantly improves the durability of the flying rafter ends and eaves tile joints of ancient buildings. 304# stainless steel plates have excellent corrosion resistance and mechanical strength, effectively resisting the erosion of rainwater and the damage from wind and sun. Under the protection of the encapsulation technology, the durability of the flying rafter ends and eaves tile joints of ancient buildings is guaranteed for a long time.

[0045] (2) In terms of decorative effect, the flying rafters and eaves tiles of ancient buildings are important components of the roof, and their aesthetics have a significant impact on the overall image of the ancient buildings. After adopting the woodwork painting and 304# stainless steel plate encapsulation with customized colors, the aesthetics of the flying rafters and eaves tiles of ancient buildings have been significantly improved. The woodwork painting restored the original color and pattern colors of the wooden components, enhancing the artistry of the ancient buildings; the smooth surface and gloss of the 304# stainless steel plate enhanced the overall texture of the ancient buildings; and the rafter style made the decorative border lines of the flying rafters more distinct and prominent, enhancing the historical sense and cultural atmosphere of the ancient buildings.

[0046] (3) In terms of economic costs, by using 304# stainless steel plates for cladding, we can significantly reduce the cost of protecting and restoring these ancient buildings. First, due to its excellent corrosion resistance and mechanical strength, 304# stainless steel plates can maintain their stability and aesthetics for a long time, thereby reducing the frequency of maintenance and replacement. This not only saves time and effort but also reduces related economic costs. Second, by customizing the rafter head decorations, the service life of the decorative border lines can be extended, thereby reducing the cost of repainting and repair.

[0047] (4) This invention adopts a multi-layer composite epoxy fluorocarbon coating, which achieves coloring and further protection of stainless steel plates at low cost. This coating has the advantages of good adhesion and low cost of epoxy resin, as well as the excellent weather resistance, acid and alkali resistance and stain resistance of fluorocarbon resin. The key to this coating is that the curing agent of the bottom layer is an isocyanate type curing agent, which is different from the commonly used aliphatic polyamine and polyamide curing agents. The isocyanate type curing agent only undergoes a cross-linking curing reaction with the hydroxyl groups in the epoxy resin, while retaining the epoxy groups. Therefore, the epoxy functional groups on the surface of the modified filler are retained in the base layer. At the same time, more than half of the modified filler is 30-40 micrometers, and the thickness of the base layer coating is 60-80 μm. Due to the large particle size of the modified filler, a considerable portion of the modified filler protrudes from the paint film surface, forming a certain roughness, and retaining the epoxy functional groups. The presence of 1-30 μm fills the gaps between the large particle size fillers, reducing the impact of the excessively large filler particle size on the density of the paint film. The combination of these factors improves the impermeability. During the curing process of the intermediate layer composite coating, the curing agent used is polyamide resin and aliphatic polyamine. Its active hydrogen reacts not only with the epoxy resin of the intermediate layer but also with the epoxy groups of the epoxy resin on the primer surface and the modified filler. In this way, the modified filler acts as an anchor between the base layer and the intermediate layer, significantly improving their adhesion. Therefore, the epoxy-functionalized silane coupling agent on the surface of the modified filler not only improves the compatibility between the filler and the resin but, more importantly, forms a chemical cross-link with the intermediate layer, significantly improving adhesion and thus enhancing water resistance and acid / alkali resistance.

[0048] (5) The intermediate layer is a composite coating of epoxy resin and fluorocarbon resin as a transition layer, which not only increases the compatibility with the epoxy coating of the base layer, but also improves the compatibility of the fluorocarbon covering layer. At the same time, the fluorocarbon resin in the intermediate layer further improves the acid and alkali resistance and weather resistance of the overall composite coating, while the addition of KH560 on the surface also improves the compatibility between epoxy resin and fluorocarbon resin.

[0049] (6) The gaps between the drip edge and the tile opening of the present invention are sealed with weather-resistant adhesive. The weather-resistant adhesive uses cement and VAE emulsion as the main components, combining the flexibility, elasticity and excellent adhesion to wood of VAE polymer with the low cost, water resistance, waterproofness and weather resistance of cement. At the same time, it uses alkali-resistant and weather-resistant pigments such as iron oxide red, so as to achieve good adhesion, water resistance and weather resistance of the filling material. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of a stainless steel sheet covering the rafter end.

[0051] Figure 2 This is a schematic diagram of a stainless steel plate encased in a corrugated frame.

[0052] In the image: 1. 304# stainless steel sheet (1.2mm thick); 2. Swastika-shaped machined pattern; 3. 304# stainless steel sheet (1.5mm thick); 4. 304# stainless steel roofing trim (1.5mm thick); 5. 304# stainless steel roofing trim (1.5mm thick); 6. 304# stainless steel rafter ends (1.2mm thick). Detailed Implementation

[0053] Example 1

[0054] The repair process of the flying rafters and eaves tile openings of ancient buildings is as follows: (1) Thoroughly clean and repair the wooden structure; (2) Construct the ground layer; (3) Paint the decoration; (4) Use 304# stainless steel plate to enclose the outside of the flying rafters and eaves tile openings, wherein the 304# stainless steel plate is coated with an epoxy fluorocarbon composite coating; (5) Seal the gap between the drip edge and the tile opening with weather-resistant adhesive; the weather-resistant adhesive is prepared from raw materials including VAE emulsion, silicate cement, pigment, polypropylene fiber, silica fume, and latex powder; the weather-resistant adhesive is prepared from the following raw material components in parts by weight: VAE emulsion 35, silicate cement 45, quartz sand 15, heavy calcium carbonate powder 8, pigment 20, polypropylene fiber 0.2, silica fume 3, latex powder 2, dispersant 0.3, defoamer 0.2, film-forming aid 1.5, preservative 0.1, silane hydrophobic agent 2, and water 20.

[0055] The epoxy fluorocarbon composite coating used in Example 2 was obtained by applying and curing the coating three times on a stainless steel plate.

[0056] It should be noted that drip tiles (also known as drip tiles) are important waterproof components at the eaves of the roof. They are fixed in the grooves of the tile openings on the eaves and correspond to the top and bottom of the rafters.

[0057] Example 2: Preparation of epoxy fluorocarbon composite coating A

[0058] The epoxy fluorocarbon composite coating has a three-layer structure, consisting of a base layer, an intermediate layer and a cover layer. Among them, (1) the base layer is made of epoxy resin primer, which contains component A and component B. Component A includes: 60 parts of epoxy resin, 12 parts of modified filler, and 5 parts of additives, specifically: 2 parts of dispersant, 0.2 parts of defoamer, 0.3 parts of leveling agent, 2.0 parts of anti-sagging agent, 0.5 parts of silane coupling agent; and 23 parts of solvent. Component B includes: 10 parts of isocyanate curing agent; wherein the modified filler is obtained by modifying silica with KH-560, and the weight ratio of particle size (30-40)μm:(10-30)μm:(1-10)μm in the modified filler is 2.5:1:1, and the coating thickness is 60μm; the epoxy resin is E-42, the curing agent is isophorone diisocyanate; the solvent is propylene glycol methyl ether acetate and methyl ethyl ketone, with a mass ratio of 3:1.

[0059] (2) The intermediate layer is made of a composite two-component intermediate paint, containing component A and component B. Component A contains the following components by weight: 35 parts epoxy resin, 25 parts fluorocarbon resin, 1 part silane coupling agent KH-560, 10 parts inorganic filler (rutile titanium dioxide), 2 parts mica powder, 2 parts calcium carbonate, 2 parts talc powder, 0.4 parts dispersant, 0.2 parts defoamer, and 23 parts solvent (propylene glycol methyl ether). Component B includes: 6 parts curing agent, which consists of 5 parts polyamide resin and 1 part triethylenetetramine. The coating thickness is 50 μm.

[0060] (3) The covering layer is prepared by a two-component fluorocarbon topcoat with a coating thickness of 70 μm. The covering layer is prepared by a two-component fluorocarbon topcoat, which includes component A and component B. Component A includes the following components by mass: FEVE fluorocarbon resin: 50 parts, 120 mesh expanded vermiculite: 12 parts, inorganic filler rutile titanium dioxide: 8 parts, inorganic pigment iron oxide red: 10 parts, dispersant: 1.5 parts, defoamer: 0.2 parts, leveling agent: 0.3 parts, matting agent: 3 parts, solvent: 15 parts, the solvent is butyl acetate and propylene glycol methyl ether acetate, with a mass ratio of 1:1; component B is hexamethylene diisocyanate trimer: 10 parts.

[0061] Example 3: Preparation of epoxy fluorocarbon composite coating B

[0062] The modified filler in the epoxy resin primer of Example 2 was replaced with conventional unmodified silica, and everything else was exactly the same as in Example 2.

[0063] Example 4: Preparation of epoxy fluorocarbon composite coating C

[0064] The epoxy resin primer of Example 2 was used instead of the composite two-component intermediate paint and two-component fluorocarbon topcoat of Example 2. Everything else was exactly the same as in Example 2, and a three-coat and curing process was used.

[0065] Example 5: Preparation of epoxy fluorocarbon composite coating D

[0066] The epoxy resin primer and two-component fluorocarbon topcoat of Example 2 were replaced with the intermediate layer composite two-component intermediate paint of Example 2. Everything else was exactly the same as in Example 2, and a three-coat and curing process was used.

[0067] Example 6: Preparation of epoxy fluorocarbon composite coating E

[0068] The two-component fluorocarbon topcoat of Example 2 was used instead of the epoxy resin primer and composite two-component intermediate paint in Example 2. Everything else was exactly the same as in Example 2, and a three-coat and curing process was used.

[0069] Performance testing

[0070] The epoxy fluorocarbon composite paint AE is prepared into a finished coating according to the common coating mixing process. The above coating is then applied to the surface of an aluminum plate, and the aluminum plate with an epoxy fluorocarbon composite coating is obtained by sequential coating and curing.

[0071] Adhesion was tested according to GB / T9286-2021 (cross-cut test).

[0072] The aging resistance was tested using an artificial accelerated aging test method, according to the requirements of Cycle A in GB / T 1865-2009 "Artificial Climate Aging and Artificial Radiation Exposure to Filtered Xenon Arc Radiation for Paints and Varnishes". The results were evaluated from the color change level according to GB / T1766 "Rating Method for Aging of Paint and Varnish Coatings". The test time was 2000 hours.

[0073] Salt spray resistance test was performed in accordance with GB / T 1771-2007 "Determination of resistance to neutral salt spray of paints and varnishes".

[0074] The evaluation criteria are: the time it takes to observe phenomena such as rust spots, blistering, and peeling of the paint film.

[0075]

[0076] As shown in the table above, the composite coating of the present invention has good adhesion to stainless steel plates, and its corrosion resistance and durability are greatly improved.

Claims

1. A repair technique for the flying rafter ends and eaves tile joints of ancient buildings, characterized in that, Includes the following steps: (1) Thoroughly clean and repair the wooden structure; (2) Construction of the ground layer; (3) Painting; (4) Use stainless steel plates to cover the outside of the flying rafter ends and the eaves tile openings; (5) The gap between the drip edge and the tile opening is sealed with weather-resistant adhesive; the weather-resistant adhesive is made from raw materials including VAE emulsion, silicate cement, pigment, polypropylene fiber, silica fume and latex powder; The stainless steel plate is coated with an epoxy fluorocarbon composite coating, which has a three-layer structure consisting of a base layer, an intermediate layer, and a cover layer. The base layer is made of an epoxy resin primer containing epoxy resin, epoxy modified filler, and isocyanate curing agent. The epoxy modified filler has a particle size of 1-40 μm, and the coating thickness is 60-80 μm. The intermediate layer is made of a composite two-component intermediate paint containing epoxy resin, fluorocarbon resin, polyamide resin, and aliphatic polyamine. The cover layer is prepared by a two-component fluorocarbon topcoat.

2. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, The weather-resistant adhesive is prepared from the following raw material components in parts by weight: 30-40 parts VAE emulsion, 40-50 parts silicate cement, 10-20 parts quartz sand, 5-10 parts heavy calcium carbonate powder, 15-25 parts pigment, 0.1-0.3 parts polypropylene fiber, 2-4 parts silica fume, 1-3 parts latex powder, and appropriate amounts of additives and water.

3. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, The stainless steel plate was replaced with aluminum.

4. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 2, characterized in that, The additives include 0.2-0.5 parts of dispersant, 0.1-0.3 parts of defoamer, 1-2 parts of film-forming aid, 0.1-0.2 parts of preservative, and / or 1-3 parts of silane hydrophobic agent.

5. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, The cleaning process involves removing surface dirt, moss, and decayed parts to reveal the wood's original color; the repair process includes filling and reinforcing cracks, dents, and holes in the wood structure.

6. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, For step (4), the facade of the tile opening is covered with a 1-3mm thick stainless steel plate and fixed with stainless steel self-tapping screws.

7. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, The eaves are also covered with 1-3mm thick stainless steel plates. The top of the eaves is covered with tile openings, and the bottom is fixed to the roof board with stainless steel self-tapping screws. 1-3 self-tapping screws are used for each rafter.

8. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, The base layer is made of epoxy resin primer, which contains component A and component B. By mass, component A includes 50-60 parts epoxy resin, 5-15 parts modified filler, 1-10 parts additives, and solvent; component B includes 5-15 parts isocyanate curing agent. The modified filler is obtained by modifying silica with epoxy functional silane coupling agent. The particle size of the modified filler is 1-40 μm, and the weight ratio of particle size (30-40) μm: (10-30) μm: (1-10) μm is (2-4): (0.5-1.5): (0.5-1.5). The coating thickness is 60-80 μm.

9. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, The intermediate layer is made of a composite two-component intermediate paint, containing component A and component B. Component A contains the following components by weight: 30-40 parts epoxy resin, 20-25 parts fluorocarbon resin, and 0.5-1.5 parts silane coupling agent KH-560. Component B includes 6-15 parts curing agent, which includes polyamide resin and aliphatic polyamine. The coating thickness is 40-60 μm.

10. The restoration process for the flying rafter ends and eaves tiles of ancient buildings according to claim 1, characterized in that, The topcoat comprises component A and component B. Component A comprises the following components by weight: FEVE fluorocarbon resin: 45.0-65.0 parts, dispersant: 1.4-2.0 parts, expanded vermiculite: 10-15 parts, inorganic filler: 5.0-10.0 parts, inorganic pigment: 8.0-12.0 parts, defoamer: 0.2-0.3 parts, leveling agent: 0.2-0.3 parts, matting agent: 2.0-5.0 parts, solvent: 2-20 parts; component B is hexamethylene diisocyanate trimer: 8-15 parts.

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