10+ Common Problems In Stone Effect Paints You Can Fix

30 / 03 / 2022

10+ Common Problems In Stone Effect Paints You Can Fix
How much do you know about stone effect paint? Do you know how to deal with various problems after using natural stone paint? Today, we summarize 10+ common problems and solutions in architectural stone paint. Let’s learn about it.
We put FAQs on the bottom of the article.

What is stone effect paint?

Stone paint is a high-grade water-based architectural paint with the decorative effect of natural stones such as marble and granite (also called marble effect paint, granite effect paint and natural stone paint). Stone effect paint is mainly made of natural stone powder of various colors and particle sizes, polymer emulsion and various additives.
Decorating with stone paint has a strong three-dimensional sense, and has the natural color of natural stone, giving people an elegant, harmonious and solemn beauty.
Stone effect paint is suitable for interior and exterior decoration of all kinds of buildings wall, especially for various curved buildings and imitation stone carvings.
The natural stone paint coating has the advantages of fire prevention, waterproof, alkali resistance, pollution resistance, non-toxic and tasteless, strong adhesion, never fading, etc. It can effectively prevent the erosion of buildings in harsh environments and prolong the service life of buildings, a generation of high-quality, high-performance concrete effect paint.

JZ-408 Stone Coating is paint that looks like stone. It is attached to the surface of buildings by simple spraying tools, so that it has the appearance of stone granite surface, and the objects can have the natural, stable, magnificent surface and the original appearance of granite.

Analysis and treatment of 10+ common problems in architectural stone paint

1. Stone coating peeled off: the coating of stone paint has poor adhesion, and the coating will fall off after a little external force. 

Cause Solution
  1. The surface of wall to be coated is not well cleaned
Clean the concrete surface to be coated before painting
  1. The bottom layer (base layer or putty layer) is not sufficiently dry
Wait until the base surface or putty layer is fully dry before construction
  1. Poor paint properties
Choose premium paint
  1. The bonding strength of the putty layer is too low
Ensure the firm adhesion of the wall putty layer without powder falling
  1. Each paint coat is too thick
Control the paint film thickness of each coat
  1. Wall Putty with high hardness, the coating film or finish is too smooth, and the bonding force between the primer and the topcoat is poor
Pay attention to the matching of primer and topcoat, and choose a primer with strong adhesion and good wetting.

2. Stone paint surface blisters or bubbles: The upper coating erodes the lower coating, making it swell and adhere poorly.

Cause Solution
  1. When the first layer of stone coating film is not dry, spray the second layer
The first coat of concrete stone effect paint should be fully dry before applying the second coat
  1. The coating is too thick
Make sure the coat is thin whenever you paint
  1. High moisture in the base layer
the moisture of the base layer is controlled below 10% and dry before construction

3. Wall crack: cracks often appear in the surface layer, and cracks often occur in the lower coating film or base layer, both of which are linear, polygonal or indeterminate cracks and fission.

Cause Solution
  1. The topcoat and primer are not compatible
Adjust the compatibility between paints and choose matching granite effect paint
  1. Carry out secondary construction before the bottom coating is dry
Proceed to the next construction after the primer was dry
  1. The paint coating is too thick
Appropriate amount of paint, avoid too thick at one time
  1. Low quality concrete effect paint with poor ductility
Choose brand stone coatings

4. Store paint turn white: after the coating is dry, stone paint coating will turn white and become loose when exposed to water, and it cannot restore its original color after exposure to sunlight.

Cause Solution
The water resistance of the coating is not good, which is caused by the absorption of water. Choose a water-repellent emulsion
Use special thickener
Add an appropriate amount of silicone waterproofing liquid to the real stone paint

5. Color differences in concrete wall after painted.

Cause Solution
  1. Use mixed paints of different colors
Test the same batch of paint with same color number before use, to ensure they are same color with wall coating we painted.
  1. Improper dilution of paint, not mixing well before use
Dilute appropriately and stir well before use
  1. Improper scraping or spraying
Apply one aspect of scraping and rolling, and use the same process for the same finish. Each process must be dry before proceeding to the next construction.
  1. After the coating is applied, it is not dry and exposed to water
Before construction, pay attention to the construction environment and weather. After the real stone paint aggregate is dry, it will cover the surface. Do not cover the surface after being drenched by rainwater, otherwise there will be water marks or flowers and whites.
  1. Uneven paint color or improper selection of raw materials
Choose high-quality paint

6. Part of the paint film surface is fluffy and rough, like a layer of hoarfrost. In severe cases, the paint film falls off, and the color becomes lighter or white.

Cause Solution
  1. The primer seal has poor alkali resistance
Improve the sealing and alkali resistance of primers
  1. Existing powders are not removed when the substrate is processed
Wait for the substrate to dry before applying
  1. The substrate is too wet and too alkaline
For substrates that are too alkaline, they must be cleaned with dilute hydrochloric acid or oxalic acid
  1. The primer is diluted too much and the performance is degraded
Dilute the primer according to the specified ratio
  1. After the exterior wall paint is briefly dried, it rains during the maintenance period of the coating film
The external wall construction must pay attention to the weather forecast to avoid construction in rainy days or being washed by heavy rain 2-3 days after construction

7. The coating film is in a state of partial sagging or accumulation and sagging

Cause Solution
  1. Coating viscosity is too low, excessive dilution
The viscosity of the coating is too low and the dilution is too high
  1. The spray gun stays in the same part for too long
The spray gun moves at a uniform speed and coats evenly
  1. The moisture content of the ground is too high, the humidity is too large, and the paint does not absorb
The base surface should be dry, and the construction should be done after meeting the requirements. It is not suitable for construction on the wall that is too wet (the moisture content of the base surface is below 10%)
  1. The primer paint is not fully dry and the continuous thick coating
Wait for the primer paint to dry before proceeding the second construction
  1. The spray gun construction pressure is uneven, and the distance between the spray gun and the finish is inconsistent
Adjust the pressure evenly, the air pressure is generally 0.4-0.7MPa (4-7kg/c㎡), the distance between the nozzle and the surface is generally 30-40cm, and keep moving at a constant speed

8. Coating film is rough: The surface of the coating film is unclean with uneven distribution of particles.

Cause Solution
  1. The construction environment is not clean, dust and sand are mixed into the paint, and there are sundries on the construction tools or sundries attached to the finish when the coating film is not drys
It is not suitable for construction in a windy or sandy environment. The environment and tools should be cleaned before construction.
  1. The base layer is uneven and smooth, with sand and dust
The basic treatment should be smooth and clean
  1. Incorrect coating or construction method
Select high-quality coatings and correct construction methods

9. The coating is too soft: In good weather, the coating can still be pulled with a fingernail after 72 hours.

Cause Solution
  1. Inappropriate stone paint selected
Emulsions with higher adhesion and higher minimum film-forming temperature should be selected; Adjust the ratio, Properly dilute evenly
  1. The ratio is unreasonable
  1. Improper dilution

10. The paint is easy to sand off

Cause Solution
  1. When using sand with higher hardness and a more compact and smooth surface, the sand is easy to fall off
Use natural sand as much as possible, and the sand has a certain gradation
  1. Improper sand grading
  1. When the coating is too thick, it will be difficult to construct. If the coating is too thin, the initial viscosity of the sand on the wall will be too low, which will cause the sand to fall.
Select high-quality emulsion, correct ratio, and increase the consistency of the coating as much as possible without difficulty in construction, which is helpful to solve the problem of sand loss
  1. Improper ratio of emulsion, the content is too low

If you still have problems about stone effect paint, welcome to contact us for free technical support.

Q: Can I use paint over stone effects? what type?
A:Yes, you can. we suggest to paint latex paint. But you need to make sure whether the finish paint is painted on the stone effect paint. If it has been painted, you only need to polish/sand it a little before paint for if it is painted directly, the paint will not adhere.
If the stone paint has been used for a long time, it can be directly painted with less impact.