1. Turbidity

Clear oil and varnish are found to have poor transparency and turbidity during transportation and storage, which is sick. If the diluent is not properly selected, too much dosage or water content, it is often one of the reasons for the muddy. Since varnishes are colloidal substances, their stability mainly depends on the solubility of various film-forming substances in the solvent. In addition, if the diluent contains a small amount of water, it will cause turbidity, which is also troublesome. Therefore, it must be noted that the diluent should not contain water. Precipitation of dry material, especially lead dry material, is also easy to make the clear paint cloudy. The cloudiness caused by the lead catalyst can be temporarily removed by heating, but it is best to filter and purify. If the turbidity is caused by mixing with water, or the storage temperature is too low, the wax in the oil will be precipitated at low temperature, which can be temporarily removed by heating.

2. Thicken

The viscosity of the coating increases gradually during the storage process, but it must be different from thixotropy. The phenomenon of increasing the viscosity due to solvent volatilization or improper use of the solvent or due to oxidative polymerization and other reactions is called thickening. Thixotropy is very similar to liver transformation in a static state, but it can move freely when stirred by external force. It is caused by the expansion of pigments and extender pigments. This cannot be said to be a malady, but an artificial one. feature. Use it to prevent paint from settling and to eliminate sag when brushing.

The acidity of the paint is too high, and it is combined with alkaline pigments to synthesize salts, which can thicken the paint and even freeze it. If the pigment contains water or water-soluble salt to wash, the paint will thicken. Others may be caused by the volatilization of the solvent and the overheating or cooling of the storage temperature. If the alkyd varnish becomes thicker, it can be solved by adding some butanol. The storage temperature is too high, and some resins that react when heated will of course thicken. In cold seasons, the viscosity will naturally increase, but this is not the viscosity of the paint itself. The increase of the height makes construction difficult, and it is recommended that the temperature of the storage site be kept at about 20 °C. Some paint bases should use salt-based pigments, the container should be closed, and the barrel should be covered after opening, preferably 2-3 days, and use up within a week at most.

3. Discoloration

Some of the solvents used in the varnish are very easy to hydrolyze and react with the iron container, dissolving some black iron compounds, and the acidic resin in the varnish also reacts with the iron container to turn red. In addition, the varnish itself reacts with the container to darken the color. For color paints, the obvious examples of various pigment fading and metallic pigments turning green and fading are blue paint and grass green paint containing Tillandsia, which faded due to the reduction effect of Tillandsia due to insufficient air in the container, but once When exposed to air, Tillandsia will recover immediately after being oxidized. Another kind of discoloration is due to the different specific gravity of several pigments in the multi-color paint, the sinking and floating of the pigments appear, and the original color can be restored only by fully stirring during use. The blackening or greening of metal pigments (aluminum powder, copper powder) is mainly due to the corrosion of aluminum powder and copper powder by free acid in oil or paint, which makes the metal lose its luster. Neutral paint can be used. The most effective method is to implement sub-packaging, which can be distributed as needed.

4. Agglomeration and precipitation

During the production and transportation process, the color paint is precipitated, and it can be reconciled after stirring, which is a normal phenomenon. If it is agglomerated after precipitation, it is a disadvantage that it cannot be stirred and dispersed again. The reason is often that the pigment used has a large proportion, coarse particles, or many fillers, the viscosity of the paint is too low, and the grinding and dispersion are poor, the wettability of the paint to the pigment is not good, the pigment reacts with the paint, or the corresponding adsorption, etc. Wait. The control method is to pay attention to the adaptability of the pigment and the binder, increase the viscosity of the paint, and add a thixotropic agent or a wetting and suspending agent.

5. Container deformation

If the storage site is improper and the weather is hot, the temperature in the tank will increase, and the solvent in the paint will gradually become a gaseous state, causing the closed iron tank to expand slowly. If it is not handled in time, it will gradually burst and leak. In case of this phenomenon, the lid of the tank can be opened, the gas in the tank can be released, and then it can be closed and moved to a cooler place.