Six Common Problems and Analysis in Putty Application

1. Bubbling: Bubbles appear during the construction process and after a period of time, bubbles appear on the surface of the putty.

Causes:

1. The substrate is too rough, and the application speed is too fast;

2. The thickness of the putty layer applied at one time is too thick, greater than 2.0mm;

3. The moisture content of the substrate is too high, with rich voids, and the putty has a high moisture content, making it non-breathable, trapping air in the voids, which cannot be expelled.

4. Bubbles that appear on the surface after a period of construction are mainly caused by uneven mixing, where undissolved powder particles are present in the slurry, absorbing moisture after application, expanding, and causing bursting.

Solutions:

1. For walls with large areas of bubbling, use a scraper to directly break the bubbles and reapply the putty on the bubbled surface.

2. Generally, after mixing the putty evenly, let it sit for about 10 minutes, then use an electric mixer to mix it again before application, and choose a low-speed, high-power model for the electric mixer.

3. If bubbling occurs in the second or final layer, appropriately reduce the water added to the putty to lower its moisture content.

4. For particularly rough walls, choose a coarser putty as the base material as much as possible.

5. In relatively high temperature or low humidity environments, first wet the wall with clean water as much as possible, and after there is no visible water on the wall, proceed with the putty application.

2. Powdering phenomenon: After construction is completed and dried, touching it with hands results in powder falling off.

Causes:

1. If the polishing time of the interior wall putty is not well controlled, polishing after the surface has dried will cause powdering;

2. For exterior wall putty, if the coating is relatively thin during finishing, moisture evaporates quickly in high summer temperatures, and the surface layer does not have enough moisture to cure, making it prone to powdering.

3. Products that exceed their shelf life have significantly reduced bonding strength.

4. Improper storage of products leads to moisture absorption and a significant decrease in bonding strength.

5. High water absorption rate of the substrate causes the putty to dry too quickly without sufficient moisture for curing.

Solutions:

1. When polishing the surface layer of interior wall putty, it is important to grasp the appropriate polishing time; the best time to polish is immediately after the watermarks on the putty surface disappear.

2. After the exterior wall putty surface dries, moderate sanding should be done, followed by sufficient watering maintenance, generally divided into two or more times for better results.

3. It is essential to use within the shelf life; if it exceeds the shelf life, a test scraping must be conducted, and only after passing inspection can construction proceed;

4. It should be stored in a cool, dry place, ensuring the packaging is intact.

5. In summer or under high temperature and strong wind conditions, it is best to first wet the wall surface with clean water before applying the putty, and the putty can be applied once there is no visible water on the wall surface.

3. Shedding phenomenon: Refers to the poor bonding strength between the putty and the substrate, leading to direct shedding from the substrate.

Causes:

1. Old wall surfaces are very smooth, resulting in poor bonding strength of the putty to the surface.

2. New wall surfaces using templates for pouring are smooth and contain a large amount of release agent (waste oil or organic silicone).

3. Directly applying putty on non-mortar substrates (such as plywood, particleboard, solid wood, etc.) like wooden or metal substrates, due to different expansion and contraction rates, and the high water absorption of these substrates, the rigid interior wall putty cannot deform accordingly, which generally leads to shedding after 2 months of construction.

4. Putty that exceeds its shelf life has reduced bonding strength.

Solutions:

1. Remove the shedding layer and treat it according to the condition of the substrate;

2. Sand the old wall surface to increase surface roughness, then treat it with a bonding agent (environmentally friendly glue or special bonding agent);

3. Use a degreasing cleaner to remove release agents or other grease from the surface before applying the putty.

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

5. For surfaces like marble, mosaic, or tiles, use a special exterior wall renovation putty for the base.

4. Delamination phenomenon: Refers to the separation between two layers of putty or between the putty and the substrate.

Causes:

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

2. The substrate is severely powdered, and its hardness is lower than that of the putty layer.

3. The substrate is too dry, with low moisture content, leading to excessive water absorption after construction.

4. The lower layer of putty is severely powdered, and if the lower layer is too hard and dries too quickly, it can also cause shedding.

5. If the interval between the application of two layers of putty is too long, generally more than 15 days, the surface layer may also cause delamination.

6. If the putty layer is soaked by rainwater or other penetrating water after or during construction, it can cause the loss of effective components in the putty, leading to shedding.

7. If the combination of two layers of putty materials is unreasonable, the difference in expansion and contraction rates is too large.

Treatment methods:

1. Remove the shedding layer and reselect a special putty for application.

2. For severely powdered construction surfaces, it is best to use a sealing primer dilution for sealing. After drying, proceed with the corresponding putty layer or other construction.

3. For putty, especially interior wall putty, try to shorten the interval between two putty applications as much as possible, but do not make the interval too short; it is recommended to be more than 6 hours.

4. Pay attention to protection during the construction process. During the putty application or within 8 hours after construction, the putty should not be soaked with water.

5. When selecting putty, it is best to consult the manufacturer, as they will provide you with professional guidance.

Five, cracking phenomenon: After a period of putty application, the surface cracks.

Causes:

1. Construction is carried out before the base layer is completely dry. The moisture content of the base layer should be ≤10%.

2. If the bottom layer of putty is not completely dry, and the surface layer dries first while the inner layer is still drying, it can cause different degrees of interlayer shrinkage, leading to cracking.

3. During base layer treatment, if the joint and leveling materials are not completely dry, and a harder interior wall putty is applied on top, it can easily cause cracking.

4. If the application is too thick, the internal drying is slower while the surface dries quickly, which can also easily cause cracking.

Solution:

1. Cracked putty needs to be removed. If the cracks are not too large, flexible putty can be used for filling, and then construction should be carried out according to standard methods.

2. Each application should not be too thick (0.5mm—1.5mm), depending on the flatness of the wall. The interval between applications must be more than 6 hours, and the previous putty must be completely dry before proceeding to the next application.

Six, yellowing phenomenon: This refers to the putty showing yellow in parts or entirely shortly after application.

Causes: This mainly occurs on old indoor walls where a large amount of polyamide glue was used. The glue ages and decomposes, producing unsaturated acids, which react with calcium ions in the putty to form corresponding yellow calcium salts.

Solution:

1. Use environmentally friendly glue or apply two coats of sealing primer, and after it is completely dry, proceed with the application of interior wall putty.

2. Use only paste-like putty for construction, or use putty specifically designed for plywood.