(1) Applicability
1. The displacement capacity of the selected sealant cannot meet the joint displacement requirements.
2. The modulus of the selected sealant does not meet the joint requirements.
3. Bonding damage.
(2) Applicability issues
1. The method of cleaning the surface of the substrate is improper, and the solvent used for cleaning is not suitable;
2. The surface cleaning of the substrate does not meet the requirements of the sealant application, and the surface of the substrate is not volatilized and dried when the sealant is applied;
3. The primer used is improper or the primer has expired before use;
4. The primer on the surface of the substrate is excessively applied, and the surface of the substrate is not volatilized and dried when the sealant is applied;
5. The sealant in the interface of the sealant is not fully compacted during the application process;
6. The contact area between the sealant and the substrate is too small to ensure the adhesion of the sealant to the substrate (unreasonable interface design);
7. The sealant is affected by external influences during the curing process, such as wind load, thermal expansion and contraction of the substrate, etc.
8. The ambient temperature during construction is lower than 5 °C, causing condensation and darkening on the surface of the substrate.
(3) Applicability issues
1. The stone curtain wall has not been tested for pollution, and it is impossible to determine whether the sealant will contaminate the substrate;
2. The use of acid glue in metal and stone curtain walls will cause chemical reaction between the glue and the substrate;
3. The bonding of the glass and the aluminum profile in the glass curtain wall uses the acid glue, and the bonding of the coated glass coating surface using the acid glue may cause the bonding failure;
4. The compatibility test and adhesion test were not performed before the start of construction, and the adhesion between the sealant and the substrate could not be guaranteed. Chemically incompatible assembly accessories (eg, seals, spacers, liner strips, retaining blocks, etc.) and sealant contact will cause discoloration of the sealant or loss of adhesion between the sealant and the substrate.
(4) Quality issues
The displacement capacity, modulus and flexibility of the sealant after curing are not up to the requirements of use.