Causes and treatment methods of putty depowdering blistering shedding yellowing and delamination

Putty powder depowder

Phenomenon: After the construction is completed and dry, the powder will drop if touched by hand

Cause: 

1. The polishing time of interior wall putty powder is not well grasped, and the surface is dried and then polishing treatment will depowder;

2. Exterior wall putty powder, the coating is relatively thin when facing. In the high temperature in summer, the moisture will evaporate quickly, and the surface layer will not have enough moisture to cure, so it is easy to depowder. To

3. The product has exceeded the shelf life, and the bonding strength has dropped significantly. To

4. The product is stored improperly, and the adhesive force drops significantly after absorbing moisture. To

5. The high water absorption rate of the base layer causes the putty to dry quickly without sufficient moisture for curing. To

Solution: 

1. When polishing the inner wall putty surface layer, it is necessary to master the appropriate polishing time. The best time for polishing is to polish immediately after the watermark on the surface of the putty disappears. Practice has proved that the veneer 1~2m2 should be flattened or polished. To

2. After the exterior wall putty surface is dry, it should be properly polished and water-sprinkled. The general maintenance is divided into two or more times. If necessary, please use a transparent sealing primer to mix with water (1:5 ) As the second spray, the effect will be better. To

3. The product must be used within the warranty period. If it exceeds the warranty period, a test scraping must be carried out. After the inspection is qualified, the construction can be carried out;

4. The product must pay attention to water-repellent treatment. It should be stored in a cool and dry place, and the encapsulation should be intact. To

5. In summer or under high temperature and strong wind conditions, it is best to wet the wall with clean water before applying putty. Putty can be applied after the surface of the wall has no clear water.

Putty foaming

Phenomenon: Bubbles are generated during the construction process and after a period of time, the surface of the putty foams. To

Cause: 

1. The base is too rough and the speed of criticism is too fast;

2. The putty layer in one construction is too thick, greater than 2.0mm;

3. The water content of the grassroots level is too high, and the density is too high or too small. Because it contains abundant voids and the putty has a high moisture content, it is not breathable, and the air is enclosed in the void cavity, which is not easy to eliminate. To

4. After a period of construction, bursts and blisters appear on the surface, mainly caused by uneven mixing. The slurry contains powdery particles that are too late to dissolve. After construction, a large amount of water is absorbed and swells to form bursts. To

Solution: 

1. If a large area of bubbling putty surface appears, use a spatula to directly crush the small foam opening, and then use a suitable putty to scrape the foamed surface layer. To

2. Putty is generally stirred evenly, then let it stand for about 10 minutes, then use an electric mixer to stir it again and put it on the wall. To

3. If there is blistering on the second or last surface of the construction, a spatula should be used to remove bubbles before the watermark is removed to ensure that no bubbles appear on the putty surface. To

4. For particularly rough walls, generally choose thick putty as the base material. To

5. In an environment where the wall is too dry or the wind is strong and the sun is strong, first wetting the wall with clean water as much as possible, and after the wall is without water, scrape the putty layer.

Putty off

Phenomenon: Refers to the poor bonding strength between the putty and the base layer, directly falling off from the base layer

Cause: 

1. The old wall is very smooth (such as tempered putty, polyurethane and other oily paint), and the putty powder has poor adhesion to the surface. To

2. The new wall is cast with a template, the surface is smooth and contains a lot of release agent (waste engine oil or silicone). To

3. For wooden substrates, metal substrates and other non-mortar substrates (such as plywood, five-plywood, particle board, solid wood, etc.), putty is directly applied. Due to the different surface expansion and contraction ratios, the water absorption rate of this type of product is relatively strong and rigid The inner wall putty cannot be deformed, and it will usually fall off after 3 months. To

4. The putty exceeds the shelf life, and the bonding strength decreases. To

Solution: 

1. Remove the peeling layer and deal with it according to the following conditions;

2. Polish the old wall to increase the surface roughness, and then use an interface agent (10% environmentally friendly glue or interface agent);

3. Use a degreasing cleaning agent to remove the release agent or other grease components on the surface, and then apply scraping putty. To

4. Use two-component or special plywood putty for construction. To

5. Please use exterior wall renovation putty for primer on exterior wall surfaces such as marble, mosaic, and ceramic tiles. To

6. Use within the putty shelf life.

Putty powder turns yellow

Phenomenon: It means that part or all of the putty appears yellow soon after the putty construction is completed.

Cause: 

It mainly occurs on the old indoor walls. The old wall putty uses a lot of PVA glue, and the glue is aged and decomposed to produce unsaturated acid. The unsaturated acid reacts with the calcium ions in the putty to generate the corresponding yellow calcium salt. To

Solution: 

1. Roll coating twice with environmentally friendly glue, and then apply putty on the interior wall after it is completely dry;

2. Roll on two coats with a sealer primer, and then scrape the putty after it is completely dry. To

3. Use paste putty for construction, or use board putty for construction.

Putty delamination

Phenomenon: peeling between two layers of putty or between putty and substrate

Cause: 

1. The substrate contains a large amount of release agent (such as waste engine oil, wax emulsion);

2. The substrate is severely chalked and the water absorption is too large. To

3. The bottom putty powder is severe, the bottom putty is too hard, and drying too fast will also cause it to fall off. To

4. The construction interval between the two layers of putty is too long, generally more than 15 days, and the finish layer sometimes causes delamination. To

5. After construction or during construction, the putty layer is infiltrated by rain or other penetrating water, causing the loss of the effective components of the putty and also falling off.

6. The collocation of two layers of putty is unreasonable. To

Solution: 

1. Remove the peeling layer and re-choose a special putty for batching;

2. For severely chalked construction surfaces, it is best to seal with 10% sealing primer diluent, and after drying, perform the corresponding putty layer or other constructions

3. Putty, especially interior wall putty, shorten the interval between two putty constructions as much as possible;

4. Pay attention to the protection during the construction process. During the construction of the putty or within 8 hours after the construction, the putty should not be infiltrated by water;

Cracking of putty

Phenomenon: The surface of the putty cracked after a period of time.

Cause: 

1. If the base layer is not completely dry, the construction requires that the moisture content of the base layer is ≤10%. To

2. The putty on the bottom layer is not completely dried, and the surface layer is dried first, while the inner layer is still in the process of drying, resulting in different degrees of shrinkage between layers and easy cracking. To

3. In the grassroots treatment, if the seams and flattening materials are not completely dry, the internal wall putty with strong hardness is applied on it, which is easy to cause cracks;

4. The construction is too thick, the internal drying is slow, the surface drying speed is faster, and it is easy to cause cracking. To

Solution: 

1. The putty that has cracked needs to be removed. If the crack is not too big, flexible putty can also be used for the first construction, and then the construction shall be carried out according to the standard construction method. To

2. Each construction should not be too thick. The time interval between the two constructions must be more than 4 hours. After the former putty is completely dry, the latter can be scraped.