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Have you encountered the 6 major problems in the construction of putty powder?

2022-12-07

bubbling
▲Phenomenon
Bubbles are generated during construction and after some time, the surface of the putty is blistered.
▲Cause
The base is too rough and the plastering speed is too fast;
② The putty layer is too thick for one construction, greater than 2.0mm;
The moisture content of the base is too high, and the density is too large or too small. Due to the rich voids and the high moisture content of the putty, it is airtight, and the air is enclosed in the void cavity, which is not easy to eliminate;
④ After a period of construction, the bursting and foaming that appeared on the surface was mainly caused by uneven stirring. The slurry contained powdery particles that were too late to dissolve. After construction, a large amount of water was absorbed, swelling and bursting.
▲Solution
① When there is a large area of foamed putty surface, use a spatula to directly crush the small bubbles, and then use a suitable putty to scrape the foamed surface layer;
②The putty is generally stirred evenly, then left to stand for about 10 minutes, then stirred again with an electric mixer and then put on the wall;
③ If foaming occurs in the second or last surface layer of the construction, use a scraper to remove the bubbles before removing the watermark to ensure that no bubbles appear on the putty surface;
④ For particularly rough walls, the general base material should be thick putty;
⑤ In an environment where the wall is too dry or the wind is strong and the light is strong, first moisten the wall with clean water as much as possible, and then scrape the putty layer after the wall has no clear water.
De-powder
▲Phenomenon
After the construction is completed and completely dried, the powder will fall off when touched by hands.
▲Cause
① The polishing time of the interior wall putty powder is not well grasped, and the surface will be de-powdered after the surface is dry;
②External wall putty powder, the coating is relatively thin when facing the surface, and the water evaporates quickly under the high temperatures in summer, The surface layer does not have enough water to cure, so it is easy to fall off the powder;
The product has exceeded the shelf life, and the bonding strength has dropped significantly;
④ Improper storage of the product, the cohesive force will drop significantly after absorbing moisture;
The high water absorption rate of the base layer causes the putty to dry quickly and there is not enough water for curing.
▲Solution
① When polishing the putty surface of the interior wall, it is necessary to master the appropriate polishing time. The best time for polishing is to polish immediately after the watermark on the putty surface disappears. The practice has proved that the surface of 1~2m2 should be flattened or polished;
After the surface of the putty on the exterior wall is dry, it should be moderately polished and fully watered for maintenance. The general maintenance is divided into two or more times. If necessary, please use a transparent sealing primer mixed with water (1:5) As the second water spray, the effect will be better;
The product must be used within the warranty period. If it exceeds the warranty period, a trial scraping must be carried out, and the construction can be carried out after passing the inspection;
④ The product must pay attention to waterproof treatment, it should be stored in a cool and dry place, and the packaging should be guaranteed to be intact;
⑤ In summer or under high temperatures and strong wind conditions, it is best to wet the wall with clean water before applying the putty. After there is no clear water on the wall surface, the putty can be applied.
fall off
▲Phenomenon
It means that the bonding strength between the putty and the base layer is poor, and it directly falls off from the base layer.
▲Cause
The old wall surface is very smooth (such as tempered putty, polyurethane, and other oil-based paints), and the bonding fastness between the putty powder and the surface is poor;
The new wall surface is poured with formwork, the surface is smooth and contains a large amount of release agent (waste engine oil or silicone);
For wooden substrates, metal substrates, and other non-mortar substrates (such as three-ply board, five-ply board, particle board, solid wood, etc....) The putty on the inner wall cannot be deformed accordingly, and it will usually fall off after 3 months;
The putty has exceeded the shelf life and the bond strength will decrease.
▲Solution
① Eradicate the exfoliated layer and deal with it in a targeted manner according to the following conditions;
②Grind the old wall to increase the surface roughness, and then use an interface agent (10% environmentally friendly glue or special interface agent);
Use a degreasing agent to remove the release agent or other grease components on the surface, and then apply the putty;
④ Use two-component or special plywood putty for construction;
⑤ For exterior wall surfaces such as marble, mosaics, and ceramic tiles, please use special exterior wall renovation putty as a primer. Use within the putty shelf life.
delamination
▲Phenomenon
Peeling between two layers of putty or between putty and substrate.
▲Cause
The substrate contains a large amount of release agent (such as waste engine oil, and wax emulsion);
The base is severely pulverized and the water absorption is too large;
The putty at the bottom layer is severely pulverized, and if the putty at the bottom layer is too hard, it will also fall off if it dries too quickly;
④ The construction interval between the two layers of putty is too long, generally more than 15 days and the finish layer may sometimes cause delamination;
⑤ After construction or during construction, the putty layer is infiltrated by rainwater or other infiltrating water, which will cause the effective components of the putty to lose and fall off;
⑥ The combination of two layers of putty is unreasonable.
▲Processing method
① Remove the exfoliated layer and re-select the special putty for plastering;
② For the severely powdered construction surface, it is best to seal it with 10% sealing primer dilution, and then carry out the corresponding putty layer or other construction after drying;
③ For putty, especially for interior wall putty, the interval between two putty constructions should be shortened as much as possible;
④ Pay attention to protection during the construction process. During the putty construction process or within 8 hours after construction, the putty is best not to be soaked by water.
Crack
▲Phenomenon
After the putty was applied for some time, the surface cracked.
▲Cause
①Construction before the base is completely dry, and the construction requires the moisture content of the base to be ≤10%;
②If the putty on the bottom layer is not completely dry, it is passed over the surface, the surface layer is dried first, and the inner layer is still in the drying process, resulting in different degrees of drying shrinkage between layers and easy cracking;
③ When treating the base layer, if the seam filling and leveling materials are not completely dry, the interior wall putty with strong hardness is scraped on it, which is easy to causes cracks;
④ If the construction is too thick, the interior will dry slowly and the surface will dry quickly, which will easily cause cracking.
▲Solution
①Cracked putty needs to be eradicated. If the cracks are not too large, flexible putty can also be used for the first construction, and then construction should be carried out according to the standardized construction method;
② Each layer of construction should not be too thick, and the time interval between two layers of construction must be more than 4 hours. After the front layer of putty is completely dry, the subsequent layer of putty should be scraped.
turns yellow
▲Phenomenon
It means that after the putty construction is completed, part or all of it will appear yellow soon.
▲Cause
It mainly occurs on old indoor walls. The old wall putty uses a large amount of PVA glue. The glue ages and decomposes, producing unsaturated acid. The unsaturated acid reacts with calcium ions in the putty to form a corresponding yellow calcium salt.
▲Solution
①Roll and coat twice with environmentally friendly glue, and then apply environmentally friendly water-based interior wall putty after it is completely dry;
② Roll two coats of white sealing primer, and after it dries thoroughly, scrape the putty again;
All constructions are made of paste putty or plate putty.

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Prescribe the right medicine to solve the five major problems of putty scraping

Putty is the same as paint construction, it is easy to cause various surface problems such as cracking, powder falling, air bubbles, etc. due to substandard material quality or improper construction. Everything is forewarned, so let us first understand some common quality problems of putty scraping, and take corresponding measures during construction to prevent these problems from appearing.

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