Lesson 1Safe Pressure Levels and Regulator Adjustments for Common Mild Steel Plate CutsSummarises safe oxygen and fuel pressure ranges for mild steel plate, proper regulator tuning, and gauge interpretation. Stresses preventing overpressure, backfires, and subpar cuts via stable, balanced settings in local workshop conditions.
Common pressures by plate thicknessAdjusting and balancing regulatorsInterpreting gaugesTuning for preheat and piercingSpotting unsafe pressure indicatorsLesson 2Basic Metallurgy of Carbon and Mild Steel for Oxy-Fuel Cutting (Thickness, Oxidation, Heat-Affected Area)Introduces essential metallurgy of carbon and mild steel for oxy-fuel cutting. Covers oxidation, heat-affected zone effects, thickness impacts, and how steel composition and structure affect cut quality and warping in practical Zimbabwean applications.
Carbon levels and steel typesIron oxidation in cuttingHeat-affected zone and hardnessThickness, mass, and heat distributionImpacts on warping and distortionIdentifying metal defectsLesson 3Cutting Methods for Straight, Square Edges (Torch Angle, Speed, Preheat, Piercing)Covers torch use for straight, square cuts, including right torch angle, distance, and speed. Details preheat timing, run-on tabs, piercing steps, and keeping a steady cut line for reliable results in boilermaking tasks.
Torch angle and nozzle distancePreheat time and melt poolPiercing steps and safetyManaging speed and cut widthRun-on and run-off tabsSteady hand controlLesson 4Edge Cleaning and Prep After Cutting (Grinding, Slag Removal, Size Checks)Outlines post-cut edge cleaning with chipping, grinding, and filing. Includes slag and dross removal, deburring, and size verification using gauges and squares to ready edges for welding, fitting, or machining in local shops.
Safe slag and dross removalGrinding and smoothing edgesDeburring holes and cornersSquareness and bevel checksLength and straightness measurementWelding edge preparationLesson 5Marking, Layout, and Measuring for Cutting Rectangular Frame Pieces (Scribing, Squares, Templates)Addresses accurate layout for rectangular frame parts using squares, scribes, and templates. Explains reference point selection, dimension transfer from plans, and marking that stays clear but limits surface harm in Zimbabwean fabrication.
Reading plans and sizesSelecting references and edgesUsing squares, tapes, rulesScribing and punching linesTemplates and guidesDiagonal and squareness checksLesson 6Pre-Use Checks and Leak Tests (Visual Inspection, Soap Test, Flashback Checks)Details pre-use inspection for cylinders, hoses, regulators, and torch. Covers soap leak testing, flashback device checks, and valve/connection verification to avoid gas leaks, flashbacks, and failures in safe boilermaking practice.
Visual hose and joint checksRegulator and gauge inspectionSoap leak test approachFlashback device testingValve function checksDefect logging and taggingLesson 7Oxy-Fuel System Parts and Upkeep (Cylinders, Regulators, Hoses, Torch, Tips, Flashback Devices)Describes oxy-fuel system parts and roles, including cylinders, regulators, hoses, torch, tips, and flashback arrestors. Includes basic upkeep, cleaning, and replacement to ensure safe, dependable use in Zimbabwean workshops.
Cylinder valves and fittingsRegulators and pressure managementHose types, colours, careTorch body, mixers, valvesTip types, cleaning, wearFlashback arrestors and valvesLesson 8Common Troubleshooting and Quality Checks (Undercut, Taper, Dross)Addresses spotting and fixing common cut issues like undercut, taper, drag lines, and dross. Offers practical tweaks to speed, tip size, pressures, and basic quality checks for production in local boilermaking settings.
Spotting undercut and washoutTaper and bevel errorsDross and drag line causesSpeed, height, angle tweaksPressure and tip fixesVisual and gauge checksLesson 9Handling, Storage, and Labelling Cut Parts (Tagging, Stacking, Rust Prevention)Covers safe handling and storage of fresh cut parts, including labelling, tagging, and position marks. Includes stacking, support use, and rust prevention to maintain sizes and tracking in Zimbabwean shop conditions.
Tagging and part labellingOrientation and fit marksSafe lifting and handlingStacking, supports, dunnageShort-term rust protectionStorage logs and labelsLesson 10Gas Choices and Tip Sizing for Common Plate Thicknesses (Acetylene vs Propane, Tip Numbers)Discusses oxygen-fuel gas options and tip sizes for typical mild steel thicknesses. Compares acetylene and propane, listing tip numbers and flows for efficient, cost-effective cutting in local fabrication work.
Acetylene vs propane comparisonGas by thickness and taskTip charts from makersTip size and hole choiceFlow rates and preheat tuningCut speed and quality effects
