Solution to common problems with exterior coatings

The quality of coating on the outer wall can directly affect the quality of the coating project. Exterior wall coating is not only related to the overall aesthetics of the wall, but also has the important role of insulation and waterproofing. In daily life, the outer wall coating often appear some such as de-powdering, foaming, cracking and other issues, how do these problems come about? How should it be solved?of structural cracks
causes to solve
structure cracks
the subsidion of foundations, changes
1. Filling the crack
2. Spreading reinforced fiber mesh
3. Select a thick layer elastic system
vibration and seam cracks interface changes between walls
2. Changes between walls and beams and windows
1. Filling the crack
2. Spreading reinforced fiber mesh
3. Thick coating system
insulation layer crack
insulation layer telescopic coefficient is greater than the surface mortar layer, so that the mortar layer cracking, the general water inspection is easier to find
1. Thick system
2. Elastic system
fine crack
putty, ash layer, cement sand ash contraction caused by
a direct coating elastic system
forming cracking
1. One construction is too thick
2. High winds
3. Paint problem
1. Control construction thickness
2. No construction in high winds
3. For paints with better crack resistance
small cracking
1. The primer or the bottom layer is
2. The elasticity of the bottom layer is 3
than
.
paint steel is too strong
1. Let the primer or the bottom layer dry out after the construction
2. Change elasticity is not less than the bottom of the paint
3. Softer paint
sealic alkali
pan-alkali causes
internal causes: high wall alkali content, PH>10
external causes: adequate moisture is necessary for pan-alkali (water content is higher than 16%)
water is alkali transport and power
Sources of water: (1) the wall itself is not volatile, (2) the water supply and drainage system is leaking, (3) the balcony, doors, windows, roofs, etc. are leaking, (4) the paint film absorbs water, and (5) the wall is cracked and absorbs water .
solution to pan-alkali:
(1) to address internal causes; Internal causes are resolved, and even if there is no more moisture, it will not be alkalin.
(2) to address external causes: make sure the water content is less than 10% before coating. Water supply and drainage to ensure that there is no leakage, rain basin boards, doors and windows, roofs, daughter wall pressure to ensure that no water, leakage.
cover force
the reasons for poor cover force and treatment:
(1) excessive dilution: more appear in white paint, inorance color paint.
solution: reduce the proportion of water added.
(2) paint is not good: mostly in darker, brighter organic colors. Such as bright red, purple, orange, these colors are expensive and poor cover (some very poor)
solution: generally through the bottom coloring solution (primer, putty coloring) such costs can be greatly reduced.
can also be solved by construction methods, using spray construction, control the gloss difference at the ground.powderingroot cause: emulsion (resin) is not enough to bond the paint and fillers in the coating.some reasons and solutions for the phenomenon ofpowdering:
(1) paint film loose unfilmed
Cause: putty layer dry and loose, without primer, coating a large amount of film-forming substances penetrate into putty Layer
solution: the choice of good material putty powder and primer(2) inside and outside the wall are present, more occurred in the days after the construction
cause: too much water caused emulsion loss such as seeping into the substrate.
solution: Reduce the proportion of water added(3) Generally occurs in winter, 2 or 3 days after construction
cause: low temperature, slow drying
Solution: extended maintenance time, try to avoid low temperature construction(4) generally occur in the plum rain season, and humid basement and other
causes : High humidity, paint difficult to completely dry into film
Solution: avoid high humidity construction, increase air circulation,
peeling
reason:
(1) putty layer water resistance is poor, paint film breathability makes moisture into the putty layer , after powdering the putty layer and the paint film out of
(2) paint film in the aging process gradually become brittle
(3) substrate surface is too smooth, no polishing treatment, surface coating bonding
(4) coating film disposable Coating is too thick to cause cracking after falling offtreatment method:
(1) remove the problematic paint film
(2) thoroughly clean the substrate
(3) If necessary, the bottom surface needs to be repaired
(4) Coating new coating system
due to the ground moisture intrusion, resulting in wall paint film peeling
reason:
because there is no or lack of protection, the water/moisture on the ground usually through the wall's capillary tube into the wall, moisture down the wall, and with salt seepage, salt crystallization makes the paint film peel off
patch:
(1) cut off the wall and water contact, this is the most fundamental solution!
(2) change the direction of moisture intrusion using special materials to repair the waterproof layer of the groundColor difference
reasons:
1, different batches of paint used on the same surface;
2, local substrate loose or leakage of primer phenomenon (especially high gloss paint), so that the gloss of the coating inconsistent resulting in uneven color;
3, uneven spraying or leakage.
solution:
1, different batches of paint in different axes separately coated;
2, construction surface putty pay attention to solid, primer rollers evenly painted,
3, training skilled sprayers before the job.Connect
true stone paint, liquid granite, rock lacquer, etc.
reasons:
1, paint viscosity when spraying is not the same;
2, the operation is not skilled, such as the angle is not correct, spraying joints in the seam outside the random stop spray or catch when not blocked, the end of a live molding finish.
Solution:
1, control paint consistency, by a person to stir, paint and air, nozzle distance from the base, angle, moving speed to be basically the same
;Lach paint, pull fur bone pulp
reasons:
1, high temperature tie more than the best time, paint in the film when hooking
2, lacquer work operation is not skilled, cloth is not enough, multi-material, uneven, random repair, etc., repeatedly pull more than the paint film time caused.
solution:1, the operation of the choice of negative construction, low wall temperature can extend the film-forming time of the paint, can buy time for construction
2, training skilled lacquer workers on duty, support and control the thickness of the fabric, uniformity and other molding, not suitable for random repair.
flowers
reasons:
1, due to uneven substation, strong light, the concave darkness, the protruse bright, giving the illusion of lacquer film hair flowers.
2, polishing putty wear through, primer can not seal the grass, paint matte dark;
3, the temperature is too high thinner does not match, paint film table dry too fast, metal pigment scheduling time is not sufficient;
solution:
1, the construction of coarse putty must be used to look for flat with a ruler vertical;
2, polishing point polishing putty after re-spraying primer, paint;
3, choose matching thinner, high temperature weather to add a moderate amount of slow-drying diluent mediation table drying time, the general drying time is controlled at 8-10 minutes.
Passing area
reasons:
1, pulled bone pulp, embossed paint, texture paint and other surface rough, to flat paint to calculate the amount of paint is not consistent

solution:
concave surface coating, to the customer reported the amount or plan paint can not be applied according to the flat coating calculation amount, generally than the flat coating area is 30-40 square meters less than a barrel calculation;
bubble
reasons:
1, the main paint did not strengthen the inhibitor, not normal cross-linking film;
2, the construction environment temperature is too high
3, paint film closed good, nearby window sills, rain basin slabs, floor surfaces, etc. have water seeping into the wall body, high temperature evaporation, gathering after the top coating;
4, the substrate is too loose, too many holes.
Solutions:
1, by product ratio ingredients;
2, avoid excessive temperature;
3, find the source of water source, do a good job of water or waterproof treatment, eliminate foaming finish to the substrate, maintenance to dry re-painting.
4, the use of good strength of professional putty.