How to apply a silicone sealant
Prepare the surface you want to apply. Before applying the silicone sealant, make sure the surface is completely free of dust, dirt or particles. Any piece of matter can potentially cause a weaker seal. To prepare the surface:
Wipe the surface to be applied with a damp cloth dipped in soapy water. Dry the area with a towel. Make sure to remove all of the water completely, as moisture can cause problems.
Prepare a hole in the silicone tube by using a knife. Cut the tube at a 45-degree angle and as close to the tip as possible. This will ensure that the hole is small enough, and easy to control the flow of sealant.
Test the silicone on a piece of waste material. If the sealant doesn't flow to your liking, then cut the tube a little more. Make cuts until the sealant flows at an ideal speed .
Apply the sealant to the surface. Squeeze the trigger as evenly and consistently as possible. Run the nozzle of the tube slowly along the joint of your project's surface.
Spread the sealant evenly. Get your finger wet and prepare some water nearby. Use your finger to spread the sealant evenly. Keep getting your finger wet as you work.
Let the sealant cure. Wait at least 24 hours for the sealant to completely cure.