Hi Temp Silicone Application Guide | Joobond

In hot, humid, and rainy weather, sealant construction becomes more challenging. For projects using hi temp silicone products, the key is to control the environment, keep substrates clean and dry, and protect the sealant during curing.

Joobond recommends checking product instructions first. For silicone sealant products, the suggested ambient range is 4°C to 40°C with 40% to 80% relative humidity. If site conditions fall outside that range, perform a small-area trial and adhesion test before full application.

Why weather matters

High temperature can speed up solvent evaporation and shorten working time. High humidity and rain can introduce moisture, affect primer performance, and reduce adhesion. On metal curtain walls, surface temperature may be much higher than the air temperature, so site conditions should be measured carefully before work begins.

1. Storage and handling

Sealants are moisture-curing products, so packaging must stay dry.

Store cartridges and cartons in a cool, ventilated, elevated, and dry area. If packaging has been soaked:

• move it out of the wet area immediately
• place it in a dry, ventilated room
• remove the outer carton
• wipe the surface dry
• inspect it before use
• use it as soon as possible after confirmation

2. Correct application steps

For structural sealant projects

This includes curtain wall structural sealant and insulating glass secondary sealant applications.

1. Clean the substrate
   Remove dust, oil, and debris. In summer, cleaning solvents evaporate quickly, so inspect the cleaning result carefully.
2. Apply primer if needed
   High temperature and humidity can reduce primer activity. Apply sealant as soon as possible after priming. Use small bottles where practical.
3. Inject the sealant
   Do not expose uncured sealant to rain, condensation, or other weather.
4. Trim immediately
   In hot weather, the finishing window is shorter, so trim right after application.
5. Record the work
   Document the construction details promptly.
6. Cure without disturbance
   Keep the assembly static and unstressed until adequate curing is achieved.

For weatherproof and door/window joints

1. Prepare the joint
   Keep the foam backer rod intact. Check substrate compatibility first.
2. Clean the substrate
   Remove contaminants completely.
3. Apply primer if needed
   The surface must be fully dry before priming, and sealant should follow quickly.
4. Inject the sealant
   After rain or thunderstorms, make sure the joint is completely dry.
5. Finish the surface
   Trim immediately after application in hot conditions.
6. Avoid movement during early curing
   Do not allow major displacement while the sealant is setting.

3. Tools, materials, and site checks

A reliable job needs the right support materials and tools.

Materials

• aluminum
• glass
• stone
• coated metal
• concrete
• foam backer rod
• primer
• masking tape
• cleaning solvent
• lint-free cloths

Tools

• caulking gun
• scraper
• trimming tool
• gloves
• temperature and humidity meter

Environmental checks

• rain
• condensation
• surface temperature
• UV exposure
• ventilation

Always confirm compatibility between the sealant, substrate, and joint design before full-scale work.

4. Practical field reminder

In hot and humid weather, the main control points are dryness, cleanliness, timing, and curing protection. For exterior curtain walls and window joints, verify site conditions first, then follow the product instructions. When conditions are uncertain, use a test area before proceeding.

About Joobond

QingDao Joobond New Materials Co. LTD has over 16 years of experience, an annual production capacity of more than 200,000 tons, and a 30,000 ㎡ facility in Shandong, China. The company focuses on high polymer polyurethane and silicone sealants, with OEM/ODM support, free samples, and quality control systems designed to support reliable construction performance.

FAQ

What temperature and humidity range is suitable for silicone sealant application?

For silicone sealant products, the recommended range is 4°C to 40°C and 40% to 80% relative humidity.

Can sealant be applied right after rain?

No. The joint must be completely dry before application.

Why is primer exposure time important in summer?

High temperature and humidity can reduce primer activity, so sealant should be applied soon after priming.

What should be checked before large-area application in difficult conditions?

Perform a small-area trial application and a peel adhesion test first.

What should be avoided during early curing?

Avoid large displacement or movement of the joint.