Surface Preparation
All surfaces must be clean and dry. All stress, static electricity, dust, grease, etc. should be removed. The applicable solvents for cleaning includes alcohol, acetone etc.

Adhesion
• GB 662 has excellent adhesion to most substrates.
• Apply the sealant to prepared surfaces
• Cure time extends when
• Priming or plasma processing is necessary for the low surface energy substrates such as PTFE, PE, PMMA ect.

Primer
• For optimal adhesion, GB primer is recommended.
• Clean the substrate surface with solvents and then apply a thin coat of primer by dipping, brushing or spraying to form a thin layer of film
• Allow the primer to dry for 5~10 minutes. Apply the silicone sealant onto the primer once the substrate surface a little sticky to finger when touched.

Site Testing
• Stir part B to ensure the homogeneity of part
• Butterfly Test
The butterfly test must be performed every time the pump is started up, including start-ups that occur after extended breaks. The purpose of this test is to check for an adequate mix of base and curing agent components
• Snap Time Test
Once full mix of the two-part sealant (as confirmed by the butterfly test) is achieved, a snap-time test should be performed. This test must be performed on a daily basis. Snap time is an indicator test that can vary from technician to technician. The snap-time test relates the base-to-catalyst mix ratio to the cure rate of the sealant, and provides an indication of working time and deep section cure

Adhesion Test
Adhesion test is to check if sealant can adhere well to substrate or not. Adhesion test should be conducted to each kind of substrate. When change substrate materials, users should send the substrates to GB to run adhesion test by GB technical people.