![Solder your first electronics joint in 90 minutes](https://cdn.slatesource.com/d/2/f/d2f2ed06-7ef4-4570-8328-bc24e1669e83.webp) # Solder your first electronics joint in 90 minutes - [Made in Slatesource](https://slatesource.com/@steph/solder-your-first-electronics-joint-in-90-minutes) - By [Steph](https://slatesource.com/@steph) - Created on Oct 27, 2026 ## What every beginner soldering guide gets wrong Every tutorial tells you to "heat the joint, not the solder." None of them explain why that one rule is the whole game. This page does. It also covers the two things that silently ruin beginner joints (the wrong cleaning method and skipping tip tinning at the end of a session), how to recognise a cold joint before it fails in a circuit, and how to desolder and start over when things go wrong. Equipment list, technique, and troubleshooting in one place. ![](https://cdn.slatesource.com/d/2/f/d2f2ed06-7ef4-4570-8328-bc24e1669e83.webp) Stealth3327 (CC0 1.0). Soldering demonstration, Tokyo, 2013. Session time 90 minutes for a first attempt Iron warm-up 2 to 3 minutes before use Difficulty Beginner, no prior electronics experience needed Starter kit cost Around $40 to $50 USD ## Step 1. Choose an iron and set the temperature A temperature-controlled station is the only real requirement. Pencil-style irons with no control run too hot, burning off flux before it can clean the joint and lifting pads off the board. Budget stations from Hakko, Pinecil, or TS100 all work well for a first kit. Set the temperature based on your solder. For leaded 63/37 or 60/40 solder, 315 to 370 degrees C (600 to 700 F) is the working range. For lead-free SAC305, set 350 to 400 degrees C. Stay at the lower end: a tip running above 380 degrees C burns off flux in under a second and produces the same grainy, unreliable joint as a tip that is too cold. The chisel tip that ships with most irons is the right choice for through-hole components. It transfers heat across a larger contact area than a conical point and makes the heat-the-joint step much easier. ## Step 2. Tin the tip before every session Oxidation is the enemy. A grey or black tip with no solder on it cannot transfer heat properly, and every joint you make on it will be a cold joint. Tinning means coating the working surface of the tip with a thin layer of fresh solder before you start. Let the iron reach temperature. Touch rosin-core solder wire to the tip and let it flow across the whole surface. The tip should look bright and silver. Wipe it gently on brass wool to remove excess. Do not use a wet cellulose sponge for routine cleaning: the thermal shock from touching a 350-degree tip to cold water causes micro-cracking in the iron-plating over time and shortens tip life. Use brass wool instead. Tin the tip again at the end of every session, before the iron cools. A tinned tip stored with a coat of solder oxidises far more slowly than a bare one. ## Step 3. Prepare the board and component Place the component through the board holes and bend the leads slightly outward on the back of the board so the component stays in place without your holding it. Both the copper pad on the board and the component lead must be clean and free from oxidation or solder mask residue. Use a third-hand tool or a clamp to hold the board flat. You need both hands free: one for the iron, one for the solder wire. Working on a moving board is the fastest way to make cold joints. ## Step 4a. Heat the joint, not the solder Touch the iron tip so it contacts BOTH the copper pad and the component lead at the same time. Hold it there for 2 seconds. Then bring the solder wire to the joint from the opposite side of the iron, not to the tip itself. Why this matters: rosin flux activates at around 150 to 200 degrees C. When you heat the joint first, both surfaces reach that temperature together, the flux cleans the metal, and solder flows into a proper bond. When you melt solder onto the iron tip instead, the flux burns off before the solder touches the joint. You get solder sitting on an oxide layer rather than bonded to it. ## Step 4b. What a correct joint looks like The solder should flow into the gap between lead and pad and form a concave fillet, like a small volcano or a cone shape. Remove the solder wire first, then the iron. Total contact time: 2 to 3 seconds for leaded, 3 to 4 for lead-free. ## Step 5. Let it cool and check the joint Do not blow on the joint. Do not touch the board for 5 seconds after lifting the iron. Any movement during cooling produces a cold joint with a grainy, frosty surface that may still pass continuity but will fail under vibration or temperature change. A good joint looks: Bright and shiny (leaded solder). Lead-free joints look slightly satin rather than mirror-bright, but should still be smooth and uniform. Concave on all sides, tapering from a wide base to the component lead. Fully wetted: no gaps between the solder and the copper pad or the component lead. A cold joint looks: Dull, grainy, or lumpy. Possibly balled up around the lead rather than flowing outward. The solder may sit on top of the pad rather than merging with it. To check: grip the component lead with tweezers and pull gently. A good joint holds firmly. A cold joint detaches with very little force, often at the solder interface. ## Step 6. Fix a cold joint Apply a small amount of additional rosin flux to the joint. Heat the joint again for 2 to 3 seconds, touching pad and lead simultaneously. Add a tiny amount of fresh solder to help the old solder reflow. Remove the iron and hold dead still. Inspect. In most cases one re-flow is enough. If the joint continues to look grainy after two re-flows, the pad may be oxidised. Apply extra flux, hold the iron on a little longer (3 to 4 seconds), and use fresh solder rather than melting the existing ball. ## Step 7. Ventilation and safety Rosin flux breaks down under heat and produces colophony fumes. These are not vaporised lead: even with lead-free solder, the rosin smoke is a recognised respiratory sensitiser that can trigger asthma with repeated exposure. Keep your face at least 30 cm (12 inches) from the joint. Solder in a well-ventilated room, or use a small fume extractor positioned between you and the iron. Do not solder for more than 15 to 20 minutes without a break in a poorly ventilated space. Wash hands before eating after a leaded solder session. Good joint (leaded) Bright, shiny, concave fillet, smooth taper to lead Good joint (lead-free) Satin, smooth, concave fillet (naturally less bright) Cold joint Dull, grainy, lumpy, balled up rather than wetted to pad Bridged pads Solder blob connecting two adjacent pads, short circuit risk Lifted pad Copper pad peeled from board, caused by too long on the iron ## Step 8. Trim and test Use flush-cut side cutters to trim the component leads as close to the solder joint as possible. Cut straight across: do not angle the cutters upward, as this can crack the joint at the base. After trimming, use a multimeter set to continuity mode and probe the pad and the component to confirm a solid connection. The meter should beep immediately. ## Step 9. Desoldering: how to undo a joint Place a piece of desoldering wick (copper braid saturated with flux) on top of the joint. Press the iron tip on top of the wick. The solder liquefies and wicks up into the braid by capillary action. Lift the wick and iron together: do not drag the wick sideways while the solder is still liquid or you risk lifting the pad. If wick alone does not remove enough solder, follow with a solder sucker. Heat the joint for 2 seconds, then place the solder sucker nozzle over the joint and press the release. For through-hole components, a single pump usually clears the hole enough to push the component lead through. One common mistake: using the iron to attack the joint repeatedly, each time removing both iron and solder and then reheating. Every cool-down cycle adds oxidation. Keep the iron on, feed in solder continuously, then remove both at once. Tip tinning 10 seconds per session, start and end Joint dwell time (leaded) 2 to 3 seconds Joint dwell time (lead-free) 3 to 4 seconds Cooling before touch 5 seconds minimum Desoldering with wick 3 to 4 seconds per joint ## Solder types at a glance Two solder specifications matter for a beginner. Leaded 63/37 (63% tin, 37% lead) is a eutectic alloy: it goes directly from solid to liquid at 183 degrees C with no pasty intermediate stage, making it the most forgiving alloy to learn on. Joints are bright and mirror-like when correct. Lead-free SAC305 (96.5% tin, 3% silver, 0.5% copper) melts at 217 to 220 degrees C and requires a 30 to 40 degree higher tip temperature. Its joints are naturally satin rather than mirror-bright, which makes cold joints harder to spot visually. It is the standard for commercial electronics production and mandatory where RoHS compliance is required. For a first session, 63/37 rosin-core wire at 0.6 to 0.8 mm diameter is the easiest material to work with. [SparkFun: How to Solder (Through-Hole)](https://learn.sparkfun.com/tutorials/how-to-solder-through-hole-soldering/all?utm_source=slatesource) [Neurochrome: Choosing the Right Solder](https://neurochrome.com/pages/choosing-solder?utm_source=slatesource) [ElectricalFlux: Soldering Temperature Guide](https://electricalflux.com/solder-buyers/best-temperature-soldering-lead-free-rosin-core-guide?utm_source=slatesource)