Introduction: Soldering Tutorial: Inline Splicing

Soldering is an essential skill for hobbyists and anyone interested in DIY electronics projects. This article will provide step-by-step instructions for inline splicing, a widely used procedure in electronic assemblies. Inline splicing involves joining two stranded wires in a straight line. The instruction is tailored for both first time solderers and intermediately skilled individuals looking to improve their technique.

Soldering iron
Solder filler wire
Stranded copper wire
Wire stripping / snipping tool

Tips and Precautions
Always exercise caution to avoid burns and electrical shock.
Use gloves and protective eyewear to minimize risk of bodily harm.
Always work in an adequately ventilated environment and avoid inhalation of vapors.
Soldering products often contain lead and may be harmful if inhaled.

Step 1: Step 1

Strip both wires approximately 1” from ends. Do not twist strands after stripping.

Note: You may choose to later insulate the splice with heat shrink tubing. If so, remember to slip on the shrink tubing before soldering the splice.

Step 2: Step 2

Align and evenly interweave the strands of both wires.

Step 3: Step 3

Carefully twist the intertwined portion of the two wires.

Step 4: Step 4

Place the spliced section on a flat surface and anchor both wires, as it is preferred to have both hands free for the next step.

Step 5: Step 5

Press the soldering iron onto the center of the splicing area.

Feed solder directly into the stranded wire adjacent to the contact point of the soldering iron.

Step 6: Step 6

Apply heat generously to evenly distribute the solder along the length of the splicing area. Next, flip the splice over and repeat for the underside.

Step 7: Done!

Your inline splice is now finished! Allow it to cool for 30 seconds before handling. The result should look similar to the picture. At this point, you may insulate the splice with shrink tubing or electrical tape. Insulation is recommended when the wire will be connected to high voltages or exposed to outdoor environmental conditions.