A caulking gun is a tool that holds a tube or cartridge that's filled with material used for sealing up gaps and cracks in the home. Caulk can be made of silicone or latex, and is used to bond a wide range of materials like metal, glass, wood and ceramic. Caulk usually comes in a tube. You need a caulking gun to get the caulk out of the tube. The gun will help you regulate how much caulk is released at one time, and will also makes the caulk come out exactly where you want it [source: Do It Yourself].

Here's how to use a caulking gun.

  1. Press the release at the rear of the gun with your thumb, releasing the plunger at the back of the gun.
  2. Pull the plunger all the way back. Put the tube into the gun, with the nozzle in the front.
  3. Push the plunger tightly into the back of the tube, and remove your thumb. The gun is now loaded.
  4. Cut the tip of the cartridge so that the hole matches the size of the gap you want to fill.
  5. Push a nail or pin through the hole to puncture any inner seal.
  6. Hold the gun at a 45 degree angle along the gap you want to seal.
  7. Squeeze the gun's handle or trigger slowly while drawing the gun toward you. When you can't squeeze the handle any more release it. It will automatically spring back. When it is in its original position, you're ready to squeeze again. How hard you squeeze the trigger and how quickly you move the gun will determine how much caulk is applied at each spot. Remember, more caulk will come out at the end of each squeeze.
  8. You can smooth out the caulk with your finger when you're done [source: Jhtianyi].