We all have a common sense: when materials are of the same thickness, goose down is warmer than cotton. The reason is that goose down has a lower specific gravity.

Basically, other materials also follow this rule. For example, in terms of specific gravity, the order is gold > copper > iron, and the order of thermal conductivity is also gold > copper > iron.

Of course, there are exceptions. For instance, diamond, the material with the fastest thermal conductivity in nature, has a very low specific gravity, which is similar to that of acrylic plastic. It is not surprising that diamond, with a low specific gravity, has the highest thermal conductivity. Essentially, this is because diamond has the highest hardness among natural materials.

The same principle applies to choosing non-foamed (non-sponge-like) thermal insulation materials: generally, the lower the specific gravity of a material, the better its thermal insulation effect. Certainly, foamed materials also follow this characteristic. For example, for common foam, the lower its specific gravity, the closer its thermal resistance value (thermal conductivity coefficient) is to that of air. Another example is graphene aerogel, which can almost float in the air; it has excellent thermal insulation performance.

Thermal insulation coatings are no exception. We can make a choice based on the actual parameter of dry density. The lower the dry density (specific gravity), the better the thermal insulation effect. The dry density of thermal insulation coatings on the market is mostly around 0.3-1.5. That is to say, although they all look similar (e.g., they all appear as paste-like substances), their thermal insulation performances vary greatly.

Reference for application thickness: 2-3 mm for temperatures ranging from -50°C to 200°C. 

The specific thickness can be increased or decreased based on requirements such as temperature difference and budget.The material is very lightweight, and the weight of the thermal insulation layer added after drying is negligible (with a specific gravity of just over 0.2 after drying).

Reference for application methods:

For general flat surfaces: Use troweling for small areas (the method and tools are the same as those for wall putty). For large areas, spraying is recommended (troweling is also acceptable). Use a putty spray pot or spray gun (professional airless putty sprayers are available).

For small components or irregularly shaped surfaces: Brushing with a hairbrush is suitable.

1、Troweling: The paste can be directly troweled after being fully stirred evenly.

2、Spraying: The amount of water added depends on the tool used. (For small-caliber pneumatic sprayers, it is generally necessary to add water to thin the paste before spraying; professional airless putty sprayers can spray the paste in a relatively thick state. Note: Adding too much water will accelerate stratification, because the main thermal insulation component has a low specific gravity and is prone to stratification when the paste is too thin. Therefore, thinning the paste too much is not recommended.)

3、Brushing: It is necessary to add an appropriate amount of water to adjust the paste before brushing. (Friendly reminder: Troweling or spraying is easier to achieve a uniform and flat surface. When brushing on vertical surfaces, if the paste is too thin, it will sag. If high surface quality is required, please use the brushing method with caution.)

When there are special requirements, the thermal insulation layer is generally used as a mid-coat (i.e., first apply the bottom anti-corrosion and waterproof layer, then the thermal insulation layer, and finally the protective topcoat to facilitate cleaning, etc. It is recommended to choose a flexible water-based waterproof coating as the topcoat). For metal surfaces, if there are no special requirements, only the thermal insulation layer is needed without the bottom coat or topcoat. For the foundation walls of buildings in humid environments, it is recommended to apply an anti-seepage primer first before adding the thermal insulation layer.