While adding radio control, battery power and sound to USA Trains locomotives, I often found that the flimsy wiring would break away from their circuit boards. My original fix was to add hot glue over the places where the wires joined the circuit boards. But hot glue can be messy to deal with and takes a while to heat up and harden.
A while ago a friend recommended Bondic Liquid Plastic Bonder. It hardens using the UV LED provided.
For gluing pieces together it is practically useless as the UV LED light cannot penetrate between two pieces. But for covering the ends of USAT or other wiring it is great! The liquid applicator has a long fine nozzle that allows the exact placement of a small amount of glue. You can make the blob a little larger if you need to. Bondic dries quickly and clear, leaving the circuit board neat and clean.
Because I removed the main USAT circuit board from an S-4 switcher to make room for a 22.5 volt battery and Revolution receiver, I had to make a number board and headlight circuit board. The new board has the required dropping resistors to protect the LEDS, and two grounds to allow the number boards to stay lit when the directional headlight goes out. As I was able to use Bondic to fix the fine wires of the LEDs to the circuit board, they did not fall out when I turned the board over to solder them in place.
