Solding LED strips

What is the best way to isolate the LED strips after solding? Recently lost signal between solding after a while. Thinking about isolating with a glue gun… is that optimal?

Isolating them from what?
Aluminum channel? -Stick a small bit of electrical tape behind the strip at the solder joint.
Water? -Hot glue may work, or silicone.

You could also sleeve the joint with marine grade adhesive lined heat shrink tubing.