It always frustrates me when I do a caulking or sealant job around the house to have to throw away a half used tube of caulk or silicon sealant or construction adhesive. I would use the provided caps and/or tape the tip, however no matter what I did the tube would be bad by the next job.
Here is a simple technique that will extend the life of a half used tube.
Step 1: What You Need
Here is what you need:
1. A circle of material cut from a milk jug.
2. A lighter or candle.
Make sure the nozzle or tip of the tube is clean of caulk.
Step 2: Use the Lighter
Step 3: Seal the End of the Tube
Step 4: Trim
This technique will not keep your half used tube fresh forever, but it will extend the time that it takes the tube to go bad by a long time.