SOP-TECH-05 · Revision 1.0

Soldering and Electronics Assembly

Instrument
Standard Operating Procedure (Level 3)
Effective
2026-09-10
Next review
2027-09-10
Room
ASB 9819, Applied Sciences Building, SFU Burnaby

This web copy is a reference version for members. The controlled copy is the signed document held by the team; in a conflict, the signed document governs. Reading it does not replace induction, training or per-activity clearance.

On this page
Document control
Implements
POL-03 (Operations: Safety, Facilities and Property) §5
Owners
Tech Team Lead, with the Operations Coordinator
Revision
1.0 — Initial release

Any change to a hazard, a control or a procedural step requires a new revision number and re-review by the Team Lead, the Operations Coordinator and the FAS Safety Officer.

Approved by the Team Lead, the Faculty Sponsor and the FAS Safety Officer; takes effect on the effective date above.

Quick-reference card Soldering

Do not operate unless

  • You are working in Lab 1, at a bench with working fume extraction.
  • You have completed the soldering briefing and have read Lab 1’s own rules.
  • Fume extraction is switched on and positioned before the iron is switched on.
  • The circuit is unpowered and any battery is disconnected.

Top hazards

  • Burns from a 350 °C tip and from solder splash
  • Rosin flux fume — a recognised respiratory sensitizer
  • Lead exposure by hand-to-mouth transfer
  • Eye injury from flicked solder and clipped leads

Required PPE

  • Safety glasses — always, no exception
  • Closed-toe, closed-heel shoes
  • Tie long hair back
  • After: Wash hands before eating

Stop / isolate

Return the iron to its stand when letting go

Switch off at the station, then at the outlet

Let it cool in the stand; never leave a hot iron loose

Lab 1 extinguisher and eyewash: locations posted in that lab

In an emergency

Fire, smoke, venting or injury: pull the alarm, evacuate, call 911, then Campus Public Safety on 778-782-4500.

Then tell the Team Lead and notify the FAS Safety Officer.

Assembly area for ASB is shown on the posted evacuation map. Do not re-enter until emergency or safety personnel authorise it.

Note

Soldering does not take place in ASB 9819. The workspace has no fume extraction, and a room holding lithium batteries is not a place to be introducing a 350 °C heat source and flux fume.

1 Scope and Applicability

This SOP covers hand soldering, desoldering and electronics assembly on Racerbot hardware: wiring looms, connectors, sensor breakouts, power distribution and repairs to vehicle electronics.

All Racerbot soldering is done in Lab 1 and follows Lab 1 rules.
  • Applies to every member soldering on Racerbot hardware.
  • Only members the Tech Team Lead has cleared, and who hold whatever access Lab 1 requires, may solder unsupervised. Otherwise, they should work with a cleared member.
  • Live-circuit work, mains-voltage work and work on anything above 60 V are outside this SOP, and will not be conducted by Racerbot.
  • Reflow, hot-air rework and solder-paste work are outside this SOP.
Never solder on a circuit that is connected to a battery. Disconnect the pack, confirm it is disconnected, and put it out of reach before the iron is switched on.

1.1 Purpose

To keep Racerbot members safe while soldering and protecting Racerbot equipment from damage.

1.2 Keywords

Soldering; desoldering; rosin flux; colophony; leaded solder; lead-free solder; fume extraction; ESD; Lab 1; SOP-TECH-01; SOP-ADM-09.

1.3 Contact

Questions about this document or the equipment it covers go to the Tech Team Lead. Questions about the workspace go to the Operations Coordinator. Questions about safety go to the FAS Safety Officer. Contact details are available to members through the team’s internal channels.

2 Introduction

Soldering is the most routine hazardous task the team does, which is exactly why it gets treated casually. The iron tip runs at around 350 °C. This is hot enough to cause a full thickness burn on contact and to ignite paper or a wire insulation offcut in seconds.

Smoke is also a hazard. The visible plume from soldering is not vaporised metal; it is rosin flux decomposition products. Rosin fume is a recognised respiratory sensitizer: repeated exposure can produce occupational asthma, and once someone is sensitized the reaction can be triggered by exposures that never bothered them before. This is why extraction runs before the iron is on, not after the smoke appears.

Where leaded solder is used, the exposure route that matters are not fume — the iron does not get hot enough to vaporise lead meaningfully — but hand-to-mouth transfer. Washing hands before eating is the whole control.

3 Equipment and Apparatus

ItemSpecificationStatus
Soldering stationTemperature-controlled station with an enclosed stand, in Lab 1. Certification mark accepted in British Columbia.Lab 1 equipment
Fume extractionBench fume extraction at the soldering position in Lab 1, switched on and positioned within about 10 cm of the joint.Lab 1 equipment
Iron standEnclosed stand with a heat-resistant sponge or brass wool. The iron lives in the stand whenever it is not in your hand.Lab 1 equipment
Fire extinguisher and eyewashLab 1’s equipment. Locate both before starting work.Lab 1 equipment
PPESafety glasses. Racerbot keeps its own set so a member is never soldering without them.In place
Hand toolsFlush cutters, strippers, helping hands or a vice, ESD-safe tweezers.In place
MultimeterFor continuity and voltage checks before and after assembly.In place

4 Materials and Supplies

  • Solder: leaded (Sn63/Pb37) or lead-free. Both are handled to the same rules in this SOP. The supplier safety data sheet for the solder in use is filed in Appendix A and is available at the bench.
  • Rosin-cored solder wire and, where used, separate flux. Rosin flux fume is the principal inhalation hazard in this procedure.
  • Isopropyl alcohol for cleaning flux residue: flammable, kept away from the iron, used only on a cold board.
  • Desoldering braid and a solder sucker.

Solder and flux are GHS-labelled products. Labels stay on the containers, and the safety data sheets are filed in Appendix A and accessible during work.

5 Hazard Assessment

TABLE 1 — HAZARD ASSESSMENT
HazardMechanism of injuryEngineering controlAdministrative controlRequired PPE
Rosin flux fumeRespiratory irritation and sensitisation; occupational asthma on repeated exposure. Once sensitised, a person reacts to exposures they previously tolerated.Bench fume extraction in Lab 1, positioned within about 10 cm of the joint; general lab ventilation.Extraction on and positioned before the iron is switched on; never soldering in ASB 9819; work stops if extraction fails; head kept out of the plume.None required with extraction working. If extraction is not working, the work does not happen.
Contact burn from the ironFull-thickness burn from a tip at around 350 °C, or from grabbing a falling iron by reflex.Enclosed iron stand; temperature-controlled station; cable routed so it cannot be snagged.Iron returns to the stand every time it leaves your hand; never pass an iron hand to hand; never catch a falling iron — let it drop and step back.Safety glasses; closed-toe shoes; no loose sleeves.
Solder splash and flicked offcutsEye injury from molten solder spitting, from flux popping, or from a clipped lead flying under tension.Component leads cut with the offcut contained under a hand or in a bin.Never shake or flick an iron to clear solder; cut leads pointing down and away; anyone at the bench wears glasses, not just the person soldering.Safety glasses — no exception, including for a single quick joint.
Lead exposureIngestion by hand-to-mouth transfer where leaded solder is used.Dedicated soldering bench separate from any eating area.No food or drink at the bench, ever; hands washed with soap and water before eating, drinking or leaving; bench wiped down after work.Wash hands. Gloves are not required and are not a substitute for washing.
Battery short during assemblyA shorted lithium pack venting or igniting while wiring is being worked on.Packs stored away from the soldering bench in their bags.Circuit fully de-energised and the pack disconnected and out of reach before the iron is switched on; continuity checked with a multimeter before a pack is reconnected.Safety glasses.

6 Hazard Control Measures

6.1 Mandatory engineering controls and PPE

Engineering controls
Bench fume extraction in Lab 1, on and positioned before the iron is on; enclosed iron stand; temperature-controlled station; bench clear of combustibles; batteries stored away from the bench.
Required PPE
Safety glasses for anyone at the bench while soldering is happening. Closed-toe, closed-heel shoes. Long hair tied back. No loose sleeves, lanyards or dangling jewellery.
Change-out
Scratched safety glasses are replaced. A frayed iron cable, a damaged stand or a sponge worn through is taken out of service and reported to Lab 1 staff and the Tech Team Lead.

6.2 GHS labels and safety data sheets

Solder, flux and isopropyl alcohol are GHS-labelled. Original labels stay on the containers, nothing is decanted into an unlabelled container, and the safety data sheets are filed in Appendix A and available at the bench during work.

6.3 Handling and storage

  • Incompatibilities: isopropyl alcohol is flammable and stays capped and away from the iron. Never clean a board with alcohol while the iron is hot or the board is powered.
  • Solder and flux are stored in their original containers, capped, at room temperature. Flux has a shelf life; a flux that has separated or dried out is discarded.
  • Racerbot tools and consumables are stored in the team’s space and carried to Lab 1 for a session, then carried back. Nothing is left in Lab 1 overnight without that lab’s agreement.

6.4 Waste disposal

  • Solder dross, desoldering braid, used tips and lead-contaminated wipes go in general waste.
  • Alcohol-soaked wipes are left to dry and placed in general waste.
  • Clipped component leads are collected into a small container and trashed.
  • Where the disposal route is unclear, ask Lab 1 staff or notify the FAS Safety Officer before binning anything.

7 Pre-Use Inspection Checklist

8 Procedure

8.1 Set up

  1. Switch on the extraction and position it near the work before anything is heated.
  2. Disconnect any battery and put it out of reach. Confirm the circuit is de-energised with a multimeter.
  3. Secure the work in helping hands or a vice. Do not hold a board in one hand and an iron in the other.
  4. Switch on the iron and set the temperature for the solder in use. Leave it in the stand while it heats.

8.2 Solder

  1. The iron goes back in the stand whenever it leaves your hand, including for two seconds.
  2. Keep your head out of the plume. Extraction pulls the fume away from you only if you are not leaning over it.
  3. Clean the tip on the sponge or brass wool. Never shake or flick the iron.
  4. Cut component leads with the offcut contained, pointing down and away from everyone at the bench.
  5. If the iron falls, let it fall and step back. Do not catch it.
  6. No food or drink at the bench at any time.

8.3 Finish

  1. Return the iron to the stand and switch off at the station, then at the outlet.
  2. Leave the iron to cool in its stand. Never put a hot iron in a drawer or a bag, and never leave it loose on the bench.
  3. Leave the extraction running for a couple of minutes after the iron is off.
  4. Clean flux residue with isopropyl alcohol on a cold, unpowered board.
  5. Clear waste to the correct streams, wipe the bench and wash your hands with soap and water.
  6. Check continuity and polarity with a multimeter before any battery is reconnected. Reconnect the pack away from the soldering bench.

8.4 Troubleshooting

SymptomLikely causeAction
Solder will not wet the jointOxidised tip, insufficient heat or a dirty padClean and re-tin the tip. Do not raise the temperature repeatedly to force it as that produces more fume and damages the board.
Heavy smoke from the jointExcess flux, or temperature set too highReduce temperature, use less flux, confirm the extraction is drawing. Stop if it does not improve.
Extraction not drawingFilter loaded or the unit is faultyStop soldering. Tell Lab 1 staff and the Tech Team Lead. Do not carry on without extraction, and do not move the work to ASB 9819 instead.
Burning smell with no visible smokeInsulation or a component overheatingSwitch off at the outlet, disconnect any power, ventilate and investigate cold. Report under SOP-ADM-09.
Board still shows a short after reworkSolder bridge or a stray offcutInspect under magnification and check with a meter. Never reconnect a pack to a board that shows a short.

9 Burns and Accidental Exposure

ExposureImmediate response
Burn from the iron or molten solderCool under clean running water for at least 15 minutes. Do not apply ice, creams or adhesive dressings, and do not pull solidified solder off the skin. Call Campus Public Safety on 778-782-4500 for first aid, or 911 for a serious burn.
Solder or flux in the eyeFlush at the eyewash for at least 15 minutes with the eyelids held open. Do not rub. Get medical attention. This always needs assessment.
Flux fume — coughing, tight chest, wheezeStop work and move to fresh air. Get medical attention for wheeze or breathing difficulty and mention rosin flux specifically. Report it: sensitization is a lasting change and the team needs to know.
Suspected lead ingestionWash hands thoroughly. Seek medical advice if a significant quantity may have been swallowed. Report under SOP-ADM-09.
Isopropyl alcohol on skin or in eyesRinse with water. For eye contact, flush at the eyewash for 15 minutes and get medical attention.

10 Decontamination and Housekeeping

  • Always wash hands with soap and water before eating, drinking or leaving.
  • Return Racerbot tools and consumables to the team’s storage.
  • Clean up your waste following §6.4 before you leave.

11 Emergency Procedures

11.1 Fire at the bench

  1. Switch off at the outlet if it is safe to do so.
  2. For anything beyond a spark that has already gone out: pull the alarm, evacuate and call 911, then Campus Public Safety on 778-782-4500.
  3. Only someone trained in extinguisher use may attempt a very small, early-stage fire, and only once the alarm is pulled and the exit is clear.
  4. If a battery is involved, follow SOP-TECH-01 §11. Do not attempt to move it.

11.2 Reporting

  • Injuries, fires, smoke, property damage, extinguisher use and near misses are reported the same day to the Team Lead and the Operations Coordinator, and to the FAS Safety Officer.
  • An SFU incident report is filed for any injury, fire, exposure, property damage or significant near miss.
  • The full process should follow SOP-ADM-09, Incident Reporting and Post-Incident Review. Reporting in good faith is never penalized, including when the person reporting caused the problem, to better aid future incident prevention.

Incidents should be reported to both Lab 1 staff and the Operations Coordinator.

Emergency contacts:

Fire, medical emergency, police911
SFU Campus Public Safety (Burnaby)778-782-4500
FAS Safety OfficerContact via the FAS Safety website

Assembly area for the Applied Sciences Building is the point shown on the evacuation map posted in ASB 9819. Do not re-enter the building until emergency or safety personnel authorise re-entry.

12 References

  • SFU Racerbot POL-03 — Operations: Safety, Facilities and Property, §5.
  • Lab 1 local rules, induction requirements and emergency procedures — that lab governs where it is stricter than this SOP.
  • SOP-TECH-01 — Lithium Battery Safety, Charging and Storage.
  • SOP-TECH-06 — Day-to-Day Lab Operations and Housekeeping.
  • SOP-ADM-09 — Incident Reporting and Post-Incident Review.
  • Solder and flux supplier safety data sheets (Appendix A.1).
  • Isopropyl alcohol safety data sheet (Appendix A.2).
  • SFU Racerbot Student Team Risk Assessment, 2026-09-10.

Appendix A — Attachments

Attachments are listed in the order they are referenced and filed behind this page.

RefDocumentDate / version
A.1Safety data sheets — solder and flux in current use
A.2Safety data sheet — isopropyl alcohol
A.3Lab 1 local rules and induction record for Racerbot members
A.4Cleared-to-solder list maintained by the Tech Team Lead