Consumables Chemicals And Materials

The consumables that repair runs on — the materials you feed the tools. Solder alloys and forms, flux and its cleaners, desoldering wick, thermal paste and adhesives, conformal coating, and wire: what each is, how to choose it, and how to handle it safely, from the metal that makes the joint to the chemicals that clean and protect the board.

• 10.1Solder Selection — Alloys and Form FactorsThe metal that makes the joint. Solder is a fusible alloy that melts, wets the metal, and solidifies into an electrical and mechanical bond. The central choice is leaded (Sn63/Pb37 eutectic — lower-melting, forgiving, but toxic and RoHS-restricted) versus lead-free (SAC tin-silver-copper — higher-melting, required for new commercial work). Then pick the form: flux-cored wire in the right diameter for hand work, paste for SMD reflow. Eutectic gives a clean, sharp-melting joint — and wash your hands after handling lead.BeginnerLow Risk23 min read
• 10.2Flux — Types, Selection, and ApplicationSolder's essential partner. Flux is the chemical that cleans the metal — it strips the oxide film that blocks wetting and keeps it off while you heat, so molten solder can flow onto the pad and lead instead of balling up. The three types are rosin (traditional, cleaned for reliability), no-clean (benign residue you can leave), and water-soluble (very active but its residue is corrosive and must be washed off). Match the activity to the job and the cleanup you can do — and reach for a flux pen, paste, or liquid whenever a joint fights you.BeginnerLow Risk22 min read
• 10.3Flux Cleaners and IPAThe cleanup half of flux. After the joint is made, residue is left behind — and whether you clean it, and how, depends on the flux. High-concentration isopropyl alcohol is the everyday solvent for rosin and no-clean residue: scrub it into a slurry, then wick that slurry away with a lint-free wipe (smear it around instead and you leave a white haze). Dedicated flux removers handle stubborn residue; water-soluble residue needs water, not alcohol, and the board must dry completely before power. And every one of these solvents is flammable — keep them away from the hot iron.BeginnerLow Risk21 min read
• 10.4Solder Wick and Desoldering ToolsSoldering in reverse. To remove a part, fix a bridge, or undo a mistake, you have to get the solder back out — and two hand tools do most of it. Solder wick is flux-cored copper braid that drinks molten solder up by capillary action, best for flat pads, SMD, and bridges. The solder sucker is a spring-loaded vacuum that snatches molten solder out of a through-hole joint. Heat the joint, apply the tool, and lift the solder before it re-freezes — and don't overheat, because the real danger here is lifting a pad.BeginnerLow Risk21 min read
• 10.5Thermal Paste and AdhesivesThe materials that aren't solder. Between a hot chip and its heatsink lies a microscopic layer of air that blocks heat — thermal paste fills those gaps so heat can cross, and it goes on thin, because too much insulates. Then there are the adhesives: cyanoacrylate and epoxy, RTV silicone and hot-melt, thread-locker and thermal epoxy — each for tacking, sealing, strain relief, or securing. The two cautions that matter: some thermal pastes are electrically conductive and will short a board, and some glues are permanent.BeginnerLow Risk22 min read
• 10.6Conformal Coating and Corrosion ProtectionThe armor over a finished board. Conformal coating is a thin polymer film that conforms to a board's every contour, sealing it against moisture, dust, and the contaminants that drive corrosion, leakage, and dendrite shorts — the reason electronics survive humid, salty, and automotive environments. Choose the type by how much protection you need against how easily you can rework it: acrylic peels off with solvent for repair, while epoxy and urethane trade removability for toughness. Clean and mask first, apply thin, cure, and check coverage under UV.IntermediateLow Risk23 min read
• 10.7Wire and Magnet Wire for RepairsThe wire that stitches a repair together. Hook-up wire jumpers two points or bridges a broken trace; magnet wire — hair-thin enameled copper — reaches into the tightest fine-pitch repairs, once you burn or scrape its enamel off so solder will take. Choose the gauge for the current it must carry (a wire too thin overheats), solid or stranded for whether it flexes, and the insulation for heat — PTFE shrugs off the iron where PVC melts back. Strip without nicking the copper, tin the strands, and you can wire almost any fix.IntermediateLow Risk22 min read
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