Soldering wires onto LED strips is a fundamental skill for customizing the length and layout of your lighting projects. A proper solder joint gives a stable, reliable connection that extends the life of your LED strips and keeps them performing. This guide walks you through soldering wires to LED strips like a professional, including the strain relief we use in our factory.
Pro tip: If you have off-cuts or old, unused LED strip, practice these steps on them a few times first. It limits wastage of the strip you actually plan to use.
Tutorial video
Tools and materials
- Temperature-controlled soldering iron with a small chisel tip. We recommend the Weller WE1010NA digital soldering station (70 W).
- Thin rosin-core solder, about 0.8 mm (0.031"). Lead-free is recommended.
- Flux pen (optional – helps the solder flow and bond)
- Stranded wire, never solid core. We use 18 AWG, with one conductor for each pad on the strip.
- Wire strippers and flush cutters
- Sharp scissors, plus a utility knife for silicone-coated strip
- Isopropyl alcohol, tape, and helping hands or tweezers
- Multimeter
- Clear UV-curing glue and a UV light, or heat-shrink tubing and a heat gun
- Fume extractor and safety glasses
Safety first
- Never solder a strip that is connected to power.
- Extract solder fumes with a fume extractor, or work in a well-ventilated area.
- Wear safety glasses.
- Hold the iron by its insulated handle and never touch the hot tip. Always return the iron to its stand.
- Keep cords clear of the hot iron.
- Let joints cool before touching them.
- Wash your hands after soldering.
- Don't look directly into a UV lamp.
Preparation
- Power off: Disconnect the strip from its power supply.
- Cut the strip: Cut only on a designated cut point, marked with a line and scissors icon, through the middle of the copper pads.
- Silicone-coated strip: Peel back the silicone at the end with a utility knife and gently clean the pads without lifting them.
- Clean and secure: Clean the pads with isopropyl alcohol and tape the strip down so it can't move.
- Set the temperature: We set our irons to about 700 °F (370 °C). A hot iron melts the solder quickly, so you spend less time heating the strip.
Soldering process
- Strip and tin the wires: Strip 3–5 mm (about 1/8") of insulation and twist the strands tight. Tin the wire with heat from below and solder from above, then trim the tinned end to the pad's length so nothing overhangs.
- Tin the pads: Rest the iron flat on each pad and feed a little solder at its edge. Leave small, separate blobs – solder must never bridge two pads. If the solder won't flow, stop and check your flux, tip, and temperature. Reheating a pad over and over can lift it off the strip.
- Join the wire – our factory technique: With the pad already tinned, quickly lay the tinned wire on the blob. Press with the iron for 1–2 seconds until both melt together. Lift the iron and hold the wire still for about a second until the joint is shiny and solid. Moving the wire while it cools makes a cold joint.
- Match polarity: Red goes to +, black to –. On multi-channel strips (tunable white, RGB, RGBW, and RGB+CCT), match every wire to the printed pad label and note which color goes where for your controller.
Inspect and test
- Check each joint: A good joint is compact, shiny, and fully attached to the pad, with no bridges between pads, no stray strands, no lifted pads, and no solder on the LEDs.
- Fix rough joints: A rough, lumpy, or frosted joint is a cold joint. Reheat it and let it cool undisturbed.
- Tug test: Give each wire a gentle tug.
- Test before you seal: Use a multimeter to check for shorts between conductors. Briefly power the strip on to confirm it lights, then power it off before sealing.
Seal the joint – the way our factory does it
Once the wires are soldered, we cover the joint with clear UV-curing glue. It acts as strain relief and protects the strip.
- Apply a thin layer over the pads and soldered wire ends, overlapping onto the wire insulation. Never cover the LED chips.
- Cure the glue with a UV light until it is hard to the touch.
- Support the cable and clip the strip into its channel, so the joint carries current, not the weight of the cable.
Alternative – heat shrink: You can seal the joint with heat-shrink tubing instead. Before you solder, slide a piece sized to fit the strip onto the wires. After testing, slide it over the joint so it covers the pads and overlaps the wire insulation, then shrink it with a heat gun on a low setting. Keep the heat gun moving so you don't overheat the LEDs. Adhesive-lined (dual-wall) tubing adds extra strain relief and moisture protection.
Waterproof strip: Add an end cap filled with neutral-cure silicone (never acid-cure silicone, which can corrode the pads). Allow 24 hours for it to cure. For the full process, see How to cut, connect, and reseal a waterproof LED strip light.
Common mistakes to avoid
- Too much heat: lifts the copper pads.
- Too much solder: bridges neighboring pads.
- Moving the wire while it cools: makes a cold joint.
- Solid-core or heavy wire: can peel the pad off the strip.
- No strain relief: the joint breaks when the cable is pulled.
Let our factory solder it for you
Rather not solder it yourself? Our Tennessee factory can do it for you. Add our solder joint service to your order:
- Solder Joint – 2 conductors: white or single-color strip
- Solder Joint – 3 conductors: tunable white (CCT) strip
- Solder Joint – 4 conductors: RGB strip
- Solder Joint – 5 conductors: RGBW strip
- Solder Joint – 6 conductors: RGB+CCT strip
Leave instructions for the joints you need in the Order Instructions box on the cart page. This is a soldering service only – LED strip and wire are sold separately.
We always recommend using a qualified installer. Always check your state and local electrical codes for AC and DC wiring.
